EEd 4 – Teaching Science in Elementary Grades PDF

BACHELOR OF ELEMENTARY EDUCATION EEd 4 – Teaching Science in the Elementary Grades Elmer A. Irene, Ed.D. College of Education  i 1 Teaching Science in Elementar...

BACHELOR OF ELEMENTARY EDUCATION EEd 4 – Teaching Science in the Elementary Grades Elmer A. Irene, Ed.D. College of Education  i 1 Teaching Science in Elementary Grades PREFACE “Give me a fish and I eat for a day. Teach me to fish and I eat for a lifetime.” This famous Chinese proverb would definitely inspire an aspiring educator like you. Truly, it is the role of a teacher to teach students how to fish, in simple words, it is your key part to teach your students to think. But how will you teach a child the right way of trawling and grilling a fish if you cannot even do these by yourself? How will you guide them into a lifetime learning if you do not know what and how to lead them? In this course, you will learn the science of teaching and learning Biology and Chemistry concepts to Elementary students. Here, you should have a “feel” of what it should be like not just as a teacher but as a learner as well. When you put yourself on the shoes of being a learner, you realize the importance of doing the right way of motivating, and not just instructing. The authors hope that the principle of John Dewey’s learning by doing and the science of learning will surface in your learning journey. SO buckle up, sit back and relax, prepare your notebook and pen as well as your gadget, and enjoy learning! EAI  1 Teaching Science in Elementary Grades ii TABLE OF CONTENTS Page No. Preface ---------------------------------------------------------------------- i Table of Contents --------------------------------------------------------- ii UNIT 1: Plants and Animals and their Habitats --------------------- 1 UNIT 2: Pedagogy in Teaching Biology Topics in Elementary Grades------------------------------------------------------ ------------------ 19 UNIT 3: MATTER AND ITS RELEVANCE TO HUMANS --------------- 32  1| Teaching Science in Elementary Grades 1 UNIT 1: Plants and Animals and their Habitats 1.0 Intended Learning Outcomes a. Describe the basic parts and function of plants and animals. b. Recognize the relevance of science process skills in coming up with scientific investigations/studies. c. Execute an activity manifesting the different science process skills. 1.1. Introduction In this unit, you will not just describe the basic parts and functions of specific concepts in Biology, but you will also be manifesting to yourself the different science process skills that your need to teach your students. These skills will be useful in understanding and executing the lessons you will be learning in this course. Enjoy! But first, let us have this pre-assessment. Instruction: Read the following situations below and write in the provided space the skills that a person must have in order to change the situations with positive outcomes. Briefly explain why these skills are needed. 1. Julia Bartito was asked by a vendor how many liters of vegetable oil does her mother requested her to buy. Julia is just 9-year-old and only know basic mathematics. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ __________________________________________________________________________. 2. Gerald Andarla was brought by her mother in the City. They were buying groceries in Lester Lace when her mother asked her to get two cans of large corned beef. He doesn’t know where to find those cans. _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________ ___________________________________________________________________. 1.2 Plants and Animals and their Habitats 1.2.1 Basic and Integrated Science Process Skills It was stated by Padilla (2018) that one of the most significant and prevalent goals of schooling is to help our student to think. In order for the schools to achieve this goal, they must share subjects that will develop the unique skills of the students. These skills include the emphasis on hypothesizing, manipulating the physical world, and reasoning from data. And one of the subjects that will advance our students to get these skills is teaching Science.  1| Teaching Science in Elementary Grades 2 Science Process Skills or SAPA (Science - A Process Approach) – are skills that are defined as a set of broadly transferable abilities, appropriate to many science disciplines and reflective of the behavior of scientists (Padilla, 2018). These skills are grouped into basic and integrated skills. What are the Basic Science Process Skills? (adapted from the online article of Padilla, 2018) -Observing - using the senses to gather information about an object or event. Example: Describing a pencil as yellow. -Inferring - making an "educated guess" about an object or event based on previously gathered data or information. Example: Saying that the person who used a pencil made a lot of mistakes because the eraser was well worn. -Measuring - using both standard and nonstandard measures or estimates to describe the dimensions of an object or event. Example: Using a meter stick to measure the length of a table in centimeters. -Communicating - using words or graphic symbols to describe an action, object or event. Example: Describing the change in height of a plant over time in writing or through a graph. -Classifying - grouping or ordering objects or events into categories based on properties or criteria. Example: Placing all rocks having certain grain size or hardness into one group. -Predicting - stating the outcome of a future event based on a pattern of evidence. Example: Predicting the height of a plant in two weeks’ time based on a graph of its growth during the previous four weeks. What are the Integrated Science Process Skills? (adapted from the online article of Padilla, 2018) -Controlling variables - being able to identify variables that can affect an experimental outcome, keeping most constant while manipulating only the independent variable. Example: Realizing through past experiences that amount of light and water need to be controlled when testing to see how the addition of organic matter affects the growth of beans. -Defining operationally - stating how to measure a variable in an experiment. Example: Stating that bean growth will be measured in centimeters per week. -Formulating hypotheses - stating the expected outcome of an experiment. Example: The greater the amount of organic matter added to the soil, the greater the bean growth. -Interpreting data - organizing data and drawing conclusions from it. Example: Recording data from the experiment on bean growth in a data table and forming a conclusion which relates  1| Teaching Science in Elementary Grades 3 trends in the data to variables. -Experimenting - being able to conduct an experiment, including asking an appropriate question, stating a hypothesis, identifying and controlling variables, operationally defining those variables, designing a "fair" experiment, conducting the experiment, and interpreting the results of the experiment. Example: The entire process of conducting the experiment on the effect of organic matter on the growth of bean plants. -Formulating models - creating a mental or physical model of a process or event. Examples: The model of how the processes of evaporation and condensation interrelate in the water cycle. After studying several researches, Padilla (2018) found that (1) applying a set of specific clues for predicting, (2) using activities and pencil and paper simulations to teach graphing, and (3) using a combination of explaining, practice with objects, discussions and feedback with observing, are the proven effective teaching strategies in learning the basic process skills. Padilla (2018) also added that studies that emphasize the Science Curriculum Improvement Study (SCIS) and SAPA indicate that if teachers will teach these skills, elementary school students can retain the process skills abilities for forthcoming use instead of just learning them. Thus, it was concluded that students will be able to learn the basic skills if they will significantly be included in teaching methods or instruction. On the other hand, we cannot expect our students to excel in demonstrating integrated skills especially if they do not have experiences or did not practice these skills. Teachers cannot assume that their students can master the experimenting skill if they practiced this in few times. They must be given multiple opportunities to practice and work within different content areas and contexts, and the teacher must be patient with this (Padilla, 2018). Padilla (2018) then concluded that teachers need to select curricula which emphasize science process skills. For us to give our students this opportunity to learn these science process skills, we need to give them various activities may it be online, offline, or whatever the trend that will definitely make our students want to learn more until develop these important skills.  1| Teaching Science in Elementary Grades 4 1.2.2 Parts and Functions of Plants and Animals 1.2.2.1 Basic Parts and Functions of Plant and Animal Cells You watched in the video the parts and functions of different organelles found in the Before you continue animal and plant cells. These are some of the reading this part of the basic knowledge you need to know before you lesson, scan the QR code or fully understand the complicated processes go to the link provided happening in the life of all living organisms and watch the video. that will lead you to conceptualizing strategies in teaching Sciences. If you can’t remember this lesson in your Junior and Senior High https://www.youtube.com/watch?v=URUJD5NEXC8&f school, maybe try your best to reread and eature=share review all your Science notes to make sure you can follow our lesson. We all know that all life shares common characteristics. One known example and very significant for us to know, is the existence of cells in all life forms. The Cell is the basic unit of life. All the Biology books you will ever read will start from teaching us how the cell functions up to how everything else gets complex. But although it is called the ‘basic’ unit of life, cell in itself is already complicated (you can say that while watching the video). It has organelles found in every single one of it and they, too, are as intricate as the cell. According to the book of (Mader and Windelspecht, 2019), when we observe plants, animals, and other organisms, it is important to realize that what we are also seeing is a vast collection of cells that work together in a highly organized, regulated manner and thus conduct the business of life. The cell is the smallest unit of living matter- but not for the non-living. Thanks to the collective work of nineteenth-century scientists Robert Brown (1773–1858), Matthias Schleiden (1804–1881), and Theodor Schwann (1810–1882) who in no other way helped us and determined that plants and animals are composed of cells. Further work by the German physician Rudolph Virchow (1821–1902) also helped us with the fact that cells actually self-reproduce and that “every cell comes from a preexisting cell.” That resolved the curiosity and facilitated us to understand that various illnesses of the body, such as diabetes and prostate cancer, are due to cellular malfunction. We can also infer that all life on Earth today came from cells in ancient times, and that all cells are related in some way. In reality, a continuity of cells has been present from generation to generation, which means the very first cell is the ancestor of the cells that do the works inside us. The work of Schleiden, Schwann, and Virchow helped created the cell theory. It states that (Mader and Windelspecht, 2019): 1. All organisms are composed of cells. 2. Cells are the basic units of structure and function in organisms. 3. Cells come only from preexisting cells because cells are self-reproducing. Fundamentally, there are two different types of cells that exist in nature. The Prokaryotic cells lack a membrane-bound nucleus while Eukaryotic cells possess a nucleus.  1| Teaching Science in Elementary Grades 5 Prokaryotes as a group are one of the most abundant and diverse life-forms on Earth, and they are present in great numbers in the air, water, and soil, as well as living in and on other organisms. What distinguishes eukaryotic cells is the presence of a nucleus and internal membrane-bound compartments, called organelles. Nearly all organelles are surrounded by a membrane with embedded proteins, many of which are enzymes. A baseline understanding of cell structure and function will be helpful when you study the function of specialized cells. Overall, the cell can be seen as a system of interconnected organelles that work together to metabolize, regulate, and conduct life processes. The following is a summary of organelles found in the animal and plant cells and their functions (Campbell et al, 2017): Nucleus- “headquarter” or the control center of the cell. The nucleus has three recognizable regions or structures: the nuclear envelope, nucleolus, and chromatin. Nuclear envelope- double membrane enclosing the nucleus; perforated by pores; continuous with Endoplasmic Reticulum. Nucleolus- non-membranous structure involved in production of ribosomes; a nucleus has one or more nucleoli. Chromatin- material consisting of DNA and proteins; visible in a dividing cell as individual condensed chromosomes. Plasma membrane- membrane enclosing the cell. Ribosomes- complexes that make proteins; free in cytosol or bound to rough ER or nuclear envelope. Golgi apparatus- organelle active in synthesis, modification, sorting, and secretion of cell products. Lysosome- digestive organelle where macromolecules are hydrolyzed. Mitochondrion- organelle where cellular respiration occurs and most ATP is generated. Peroxisome- organelle with various specialized metabolic functions; produces hydrogen peroxide as a by-product and then converts it to water. Microvilli- projections that increase the cell’s surface area. Cytoskeleton- reinforces cell’s shape; functions in cell movement; components are made of protein. Includes: microfilaments, intermediate filaments and microtubules. Centrosome- region where the cell’s microtubules are initiated; contains a pair of centrioles. Flagellum- motility structure present in some animal cells, composed of a cluster of microtubules within an extension of the plasma membrane. Endoplasmic Reticulum (ER)- network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes; has rough (ribosome- studded) and smooth regions.  1| Teaching Science in Elementary Grades 6 Cytoplasm- semifluid matrix outside nucleus that contains organelles. Chloroplast*- carries out photosynthesis, producing sugars. Cell wall*- outer surface that shapes, supports, and protects cell. Central vacuole*: large, fluid-filled sac that stores metabolites and helps maintain turgor pressure. * only found in plant cells. Plant Cell Animal Cell Cell wall is present. No cell wall is present. Cells connect with plasmodesmata. Cells connects with various junctions. Cell division involves a cell plate. Cell division involves a cleavage furrow. No centrioles are present during Centrioles are present during mitosis. mitosis. Plastids are present. No plastids are present. Vacuoles are large. Vacuoles are small or absent. Table 1.1. Comparison between Animal and Plant Cell. Mader and Windelspecht (2019) 1.2.2.2 Plant and Animal Tissues PLANT TISSUES The body of a plant is organized in a similar fashion to the body of an animal. Tissue is composed of specialized cells that perform a particular function, and an organ is a structure made up of multiple tissues. In the case of a plant, embryo first begins to develop and its first cells are called meristem cells. Like animal stem cells, plant meristem cells are undifferentiated cells that can divide indefinitely and give rise to many types of differentiated cells. As new cells are produced, they are small and boxlike, with a large nucleus and tiny vacuoles. As these cells mature, they assume many different shapes and sizes, each related to the cell’s ultimate function. When a seed germinates and an embryo grows, meristem tissue is present at the tips, or apices, of the young plant and are called apical meristems. Apical meristems in turn give rise to three specialized meristems that create the differing plant tissues (Mader and Windelspecht, 2019). Mader and Windelspecht (2019)  1| Teaching Science in Elementary Grades 7 The following are the plant tissues presented by Mader and Windelspecht (2019): Epidermal Tissue The entire body of both nonwoody (herbaceous) and young woody plants contains closely packed epidermal cells called the epidermis. The walls of epidermal cells that are exposed to air are covered with a waxy cuticle to minimize water loss. The cuticle also protects against bacteria and other organisms that might cause disease. In roots, certain epidermal cells have long, slender projections called root hairs. The hairs increase the surface area of the root for absorption of water and minerals, as well as anchoring the plant to various substrates. On stems, leaves, and reproductive organs, epidermal cells produce hairs, called trichomes, that have two important functions: to protect the plant from too much sun and moisture loss and to discourage herbivory (plant eating). In leaves, the lower Mader and Windelspecht (2019) epidermis of eudicots and both surfaces of monocots contain Figure 1.1. The Epidermal Tissue specialized cells called guard cells. Guard cells, which are epidermal cells with chloroplasts, surround microscopic pores called stomata. When the stomata are open, gas exchange and water loss occur. In plants with wood, the epidermis of the stem is replaced by cork cells. New cork cells are made by a meristem called cork cambium. This entire cork area of the plant is called the periderm. As the new cork cells mature, they increase slightly in volume, and their walls become encrusted with suberin, a lipid material, so that they are waterproof and chemically inert. The cork cambium overproduces cork in certain areas of the stem surface, causing ridges and cracks to appear. These features on the surface are called lenticels. Lenticels are the site of gas exchange between the interior of a stem and the air. Study figure 1.1 to know the structures of the terms mentioned.  1| Teaching Science in Elementary Grades 8 Ground Tissue Ground tissue forms the bulk of a flowering plant; it contains parenchyma, collenchyma, and sclerenchyma cells (see figure 1.2). Parenchyma cells are the most abundant and correspond best to the typical plant cell. These are the least specialized of the cell types and are found in all the organs of a plant. They may contain chloroplasts and carry-on photosynthesis, or they may contain colorless plastids that store the products of photosynthesis. Parenchyma cells can divide and give rise to more specialized cells, as when roots develop from stem cuttings placed in water. Collenchyma cells are like parenchyma cells except they have thicker primary walls. The thickness is uneven and usually involves the corners of the cell. Collenchyma cells often form bundles just beneath the epidermis and give flexible support to immature regions of a plant body. The familiar strands in celery stalks are composed mostly of collenchyma cells. Sclerenchyma cells have thick secondary cell walls impregnated with lignin, which is a highly resistant organic substance that makes the walls tough and hard. Most sclerenchyma cells are dead at maturity; their primary function is to support the mature regions of a plant. Two types of sclerenchyma cells are fibers and sclereids. Fibers are long and slender and may be grouped in bundles, which are sometimes commercially important. Hemp fibers can be used to make rope, and flax fibers can be woven into linen. Flax fibers, however, are not lignified, which is why linen is soft. Sclereids, which are shorter than fibers and more varied in shape, are found in seed coats and nutshells. Sclereids, or “stone cells,” are responsible for the gritty texture of pears and the hardness of nuts and peach pits. Mader and Windelspecht (2019) Figure 1.2. The Ground Tissue Vascular Tissue There are two types of vascular tissue. Xylem transports water and minerals from the roots to the leaves, and phloem transports sucrose and other organic compounds, usually from the leaves to the roots. Both xylem and phloem are considered complex tissues, because they are composed of two or more kinds of cells. In the roots, the vascular tissue is located in the vascular cylinder; in the stem, it forms vascular bundles; and in the leaves, it is found in leaf veins. Xylem contains two types of conducting cells: tracheids and vessel elements, which  1| Teaching Science in Elementary Grades 9 are modified sclerenchyma cells. Both types of conducting cells are hollow and dead, but the vessel elements are larger, may have perforation plates in their end walls, and are arranged to form a continuous vessel for water and mineral transport. The elongated tracheids, with tapered ends, form a less obvious means of transport, but water can move across the end walls and side walls, because there are pits, or depressions, where the secondary wall does not form. In addition to vessel elements and tracheids, xylem can contain sclerenchyma fibers that lend additional support as well as parenchyma cells that store various substances. Vascular rays, which are flat ribbons or sheets of parenchyma cells located between rows of tracheids, conduct water and minerals across the width of a plant. The conducting cells of phloem are specialized parenchyma cells called sieve-tube members, arranged to form a continuous sieve tube. Sieve-tube members contain cytoplasm but no nuclei. The term sieve refers to a cluster of pores in the end walls, which is known as a sieve plate. Each sieve-tube member has a companion cell, which contains a nucleus. The two are connected by numerous plasmodesmata, and the nucleus of the companion cell may control and maintain the life of both cells. The companion cells are also believed to be involved in the transport function of phloem. Sclerenchyma fibers also lend support to phloem. ANIMAL TISSUES According to what Charles Darwin (1909) noted on his book “Origin of Species”, while the planet Earth has cycled year after year around the sun, “endless forms most beautiful and most wonderful” have appeared and will keep on appearing. This statement only shows that there are variety of animals in the world that were discovered and will be discovered in several times. But despite that diversity, as stated by Mader and Windelspecht (2019), animals have an unbroken thread of unity, provided by evolution from a common ancestor. At the biosphere level, animals are heterotrophic consumers that require a constant supply of food, ultimately supplied by the autotrophs at the base of the food chain. At the organismal level, organs are composed of tissues, and each type of tissue has cells that perform specific functions. Let us take a brief discussions of the tissues found in the animals (Mader and Windelspecht, 2019): Epithelial Tissue Epithelial tissue, also called epithelium, consists of tightly packed cells that form a continuous layer. Epithelial tissue covers surfaces and lines body cavities. Usually, it has a protective function, but it can also be modified to carry out secretion, absorption, excretion, and filtration. Epithelial cells may be connected to one another by three types of junctions composed of proteins. Regions where proteins join them together are called tight junctions. Epithelial tissues are often exposed to the environment on one side, but on the other side they are attached to a basement membrane. The basement membrane is simply a thin layer of various types of proteins that anchors the epithelium to the extracellular matrix, which is often a type of connective tissue.  1| Teaching Science in Elementary Grades 10 There are five (5) types of epithelial tissue: 1. Simple epithelia have only a single layer of cells and are classified according to cell type: a. Squamous epithelium- is composed of flattened cells, lines blood vessels and the air sacs of lungs. b. Cuboidal epithelium- contains cube-shaped cells and is found lining the kidney tubules and various glands. c. Columnar epithelium- has cells resembling rectangular pillars or columns, with nuclei usually located near the bottom of each cell. 2. Stratified epithelia have layers of cells piled one on top of the other. Only the bottom layer touches the basement membrane. 3. Glandular Epithelia is when an epithelium secretes a product. A gland can be a single epithelial cell, as in the case of mucus-secreting goblet cells within the columnar epithelium lining the digestive tract, or a gland can contain many cells. a. Exocrine glands- secrete their product into ducts. b. Endocrine glands- have no duct, and secrete hormones internally, so they are transported by the bloodstream. Connective Tissue Connective tissue is the most abundant and widely distributed tissue in complex animals. It is quite diverse in structure and function; even so, all types have three components: specialized cells, ground substance, and protein fibers. The ground substance is a noncellular material that separates the cells and varies in consistency from solid to semifluid to fluid. The fibers are of three possible types. White collagen fibers contain collagen, a protein that gives them flexibility and strength. Reticular fibers are very thin collagen fibers that are highly branched and form delicate supporting networks. Yellow elastic fibers contain elastin, a protein that is not as strong as collagen but is more elastic. The ground substance plus the fibers together are referred to as the connective tissue matrix. Connective tissue is classified into three major categories: 1. Fibrous Connective Tissue- both loose fibrous and dense fibrous connective tissues have cells called fibroblasts, located some distance from one another and separated by a jellylike matrix containing white collagen fibers and yellow elastic fibers. a. Loose fibrous connective tissue: o has space between components. o occurs beneath skin and most epithelial layers. o functions in support and binds organs. b. Adipose connective tissue: o cells are filled with fat. o occurs beneath skin, around heart and other organs. o functions in insulation, stores fat.  1| Teaching Science in Elementary Grades 11 c. Dense fibrous connective tissue o has collagenous fibers closely packed. o in dermis of skin, tendons, ligaments. o functions in support. 2. Supportive Connective Tissue- provide structure, shape, protection, and leverage for movement. Cartilage and bone are the two main supportive connective tissues. a. Cartilage. The cells lie in small chambers called lacunae, separated by a matrix that is solid yet flexible. Unfortunately, because this tissue lacks a direct blood supply, it heals very slowly. There are three types of cartilage, distinguished by the type of fiber in the matrix. o Hyaline cartilage- the most common type of cartilage, contains only very fine collagen fibers. The matrix has a white, translucent appearance. It is found in the nose and at the ends of the long bones and the ribs, and it forms rings in the walls of respiratory passages. The fetal skeleton also is made of this type of cartilage. o Elastic cartilage- has more elastic fibers than hyaline cartilage. For this reason, it is more flexible and is found, for example, in the framework of the outer ear. o Fibrocartilage has a matrix containing strong collagen fibers. Fibrocartilage is found in structures that withstand tension and pressure, such as the pads between the vertebrae in the backbone and the wedges in the knee joint. b. Bone. Of all the connective tissues, bone is the most rigid. It consists of an extremely hard matrix of inorganic salts, notably calcium salts, deposited around protein fibers, especially collagen fibers. The inorganic salts give bones rigidity, and the protein fibers provide elasticity and strength, much as steel rods do in reinforced concrete. o Compact bone makes up the shaft of a long bone. It consists of cylindrical structural units called osteons. o Spongy bone contains numerous bony bars and plates, separated by irregular spaces. Although lighter than compact bone, spongy bone is still designed for strength, just as braces are used for support in buildings. 3. Fluid Connective Tissues- (blood) which consists of formed elements and plasma, is a fluid connective tissue located in blood vessels. Formed elements in the blood consist of the many kinds of blood cells and the platelets. Blood transports nutrients and oxygen to interstitial fluid and removes carbon dioxide and other wastes. It helps distribute heat and plays a role in fluid, ion, and pH balance. o Red Blood Cells- Contains a red color pigment called hemoglobin which helps in transportation of oxygen. o White Blood Cells- These cells help to fight against infections. o Platelets- helps in clotting of blood. o Lymph- It helps in the transportation of substances.  1| Teaching Science in Elementary Grades 12 Muscular Tissue Muscular (contractile) tissue is composed of cells called muscle fibers. Muscle fibers contain actin filaments and myosin filaments, whose interaction accounts for movement. The muscles are also important in the generation of body heat. There are three distinct types of muscle tissue: 1. Skeletal muscle- also called voluntary muscle is attached by tendons to the bones of the skeleton, and when it contracts, body parts move. Contraction of skeletal muscle is under voluntary control and occurs faster than in the other muscle types. Skeletal muscle fibers are cylindrical and quite long—sometimes they run the length of the muscle. 2. Smooth (visceral) muscle- is so named because the cells lack striations. The spindle-shaped cells, each with a single nucleus, form layers in which the thick middle portion of one cell is opposite the thin ends of adjacent cells. Smooth muscle is not under voluntary control and therefore is said to be involuntary. Smooth muscle, found in the walls of viscera (intestine, stomach, and other internal organs) and blood vessels, contracts more slowly than skeletal muscle but can remain contracted for a longer time. When the smooth muscle of the intestine contracts, food moves along its lumen (central cavity). When the smooth muscle of the blood vessels contracts, blood vessels constrict, helping raise blood pressure. 3. Cardiac muscle- is found only in the walls of the heart. Its contraction pumps blood and accounts for the heartbeat. Cardiac muscle combines features of both smooth muscle and skeletal muscle. Like skeletal muscle, it has striations, but the contraction of the heart is involuntary for the most part. Cardiac muscle cells also differ from skeletal muscle cells in that they usually have a single, centrally placed nucleus. The cells are branched and seemingly fused one with the other, and the heart appears to be composed of one large, interconnecting mass of muscle cells. Nervous Tissue Nervous tissue contains nerve cells called neurons and supporting cells called neuroglia. An average human body has about 1 trillion neurons. The nervous system conveys signals termed nerve impulses throughout the body. 1. Neuron is a specialized cell that has three parts: dendrites, a cell body, and an axon. A dendrite is a process that conducts signals toward the cell body. The cell body contains the major portion of the cytoplasm and the nucleus of the neuron. An axon is a process that typically conducts nerve impulses away from the cell body. Long axons are covered by myelin, a white, fatty substance. The term fiber is used here to refer to an axon along with its myelin sheath, if it has one. Outside the brain and spinal cord, fibers bound by connective tissue form nerves. 2. Neuroglia outnumber neurons as much as ten to one, and they make up approximately half the volume of the organ. Although the primary function of neuroglia is to support and nourish neurons, recent research has shown that some neuroglia directly contributes to brain function. Several types of neuroglia are found in the brain: microglia, astrocytes, and oligodendrocytes.  1| Teaching Science in Elementary Grades 13 1.2.2.3 Organs and Organ Systems of Animals As discussed by Mader and Windelspecht (2019), an organ is composed of two or more types of tissues working together to perform a particular function. For example, a kidney is an organ that contains a variety of epithelial and connective tissues, and these tissues are specialized for the function of eliminating waste products from the blood. In most animals, individual organs function as part of an organ system. An organ system contains many different organs that cooperate to carry out a general process, such as the digestion of food. Similar types of organ systems are found in most invertebrates, as well as in all vertebrate animals. These organ systems carry out the life processes that all of these animals, including humans, must carry out. Below is the summary of the contributions of each organ system to the human body (Longenbaker, 2017): o Integumentary System—external support and protection of body; helps maintain body temperature. o Skeletal System—internal support and protection; body movement; production of blood cells. o Muscular System—body movement; production of heat that maintains body temperature. o Nervous System—regulatory center for control of all body systems; learning and memory. o Endocrine System—Secretion of hormones for chemical regulation of all body systems. o Cardiovascular System—transport of nutrients to body cells and transport of wastes away from cells. o Lymphatic System—drainage of tissue fluid; purifies tissue fluid and keeps it free of pathogens. o Respiratory System—rids the blood of carbon dioxide and supplies the blood with oxygen; helps maintain the pH of the blood. o Digestive System—breakdown of food and absorption of nutrients into blood. o Urinary System—maintenance of volume and chemical composition of blood. o Reproductive System—Production of sperm and egg; transfer of sperm to female system where development occurs. INDEPENDENT LEARNING. As you can observe in the above list, there are numbers of organ systems which work together for a living organism to function well. Each of these organ systems have many different organs that cooperate to carry out a general process. For you independent learning, look for references, as many as you can, or one reference if you want (whichever is convenient to you) and study the different organs of all the organ systems. Remember that questions on your summative tests will include this part, so you have to do your best to familiarize the organs of the organ systems.  1| Teaching Science in Elementary Grades 14 1.2.2.4 The Shoot System and Root System The body of a plant consists of a root system and a shoot system. The shoot system contains the stem and leaves, two types of plant vegetative organs. Axillary buds can develop into branches of stems or flowers, the reproductive structures of a plant. The root system is connected to the shoot system by vascular tissue (brown) that extends from the roots to the leaves (Mader and Windelspecht, 2019). The shoot system of a plant is composed of the stem, the branches, and the leaves. A stem supports the leaves in a way that exposes each one to as much sunlight as possible. In addition, the stem transports materials between roots and leaves and produces new tissue. At the end of a stem, a terminal bud contains an apical meristem and produces new leaves and other tissues during the initial primary growth of a plant (see fig. 1.3). Lateral (side) branches grow from a lateral bud located at the angle where a leaf joins a stem. A node occurs where a leaf or leaves are attached to the stem, and an internode is the region between nodes. Vascular tissue transports water and minerals from the roots through the stem to the leaves and transports the products of photosynthesis, usually in Mader and Windelspecht (2019) the opposite direction. The root system simply consists of the roots. Figure 1.3. Organization of a Plant body The root tip also contains an apical meristem and results in primary growth downward. Ultimately, the three vegetative organs—the root, the stem, and the leaf—perform functions that allow a plant to live and grow. LET’C CHECK YOUR PROGRESS! To understand more the difference Briefly answer the following questions below. between the shoot and the root system. Scan this QR code. 1. Describe how the plant body is organized? ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ 2. List the three vegetative organs in a plant, and state their major functions. ____________________________________________________________ ____________________________________________________________ ___________________________________________________________  1| Teaching Science in Elementary Grades 15 ASSESSMENT Quiz No. 1. Label the parts of the plant and animal shown below and describe the function of each part in the table that follows. Plant Animal Plant Part Function  1| Teaching Science in Elementary Grades 16 Animal Part Function Quiz No. 2 Research two scientific investigations/studies about the plant and animal cell. Write the title of the study and summarize the results and discussions. List all the science process skills you think were used and how each of these skills contributed in the conduct of each study. ___________________________________________ (Title of the study) Summary: ____________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ ______________________________________________________. List of Science Process Skills and their contribution: (Give at least three skills) __________________-_______________________________________________________________. __________________-_______________________________________________________________. __________________-_______________________________________________________________.  1| Teaching Science in Elementary Grades 17 ___________________________________________ (Title of the study) Summary: ____________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ ______________________________________________________. List of Science Process Skills and their contribution: (Give at least three skills) __________________-_______________________________________________________________. __________________-_______________________________________________________________. __________________-_______________________________________________________________. Class Participation 1. Demonstrate through a Tiktok video how will you execute a specific activity manifesting the different science process skills. (Non-tiktok users may only send a short video.) 1.3 References Darwin, C. (1909). The origin of species. New York: PF Collier & son. Longenbaker, Susannah N. (2017) Mader’s Understanding Human Anatomy & Physiology, Ninth Edition. McGraw Hill Education. Mader, Sylvia S. and Windelspecht (2019). BIOLOGY 13th Edition: McGrew-Hill Education. 2 Penn Plaza, New York, NY 10121. Nuclues Medical Media. (2015). Biology: Cell Structure [Video]. https://www.youtube.com/watch?v=URUJD5NEXC8&feature=share Smith, Gorrzynski *(2013). General, Organic & Biological Chemistry: McGrew-Hill International Edition. 1.4 Acknowledgment The images, tables, figures and information contained in this module were taken from the references cited above.  1 2 | Teaching Science in Elementary Grades 19 UNIT 2: Pedagogy in Teaching Biology Topics in Elementary Grades 2.0 Intended Learning Outcomes a. Describe the basic parts and function of plants and animals. b. Recognize the relevance of science process skills in coming up with scientific inves- tigations/studies. c. Execute an activity manifesting the different science process skills. 2.1. Introduction Considering the Enhanced Basic Education curriculum, teaching should follow a spiral progression of concepts which means learners should encounter formal education from most basic to the most complex as they engage in the learning process (Department of Education, 2013). Take note, in the K-12 curriculum, teaching Biology or Physics or Chemistry alone is no longer the trend. All these branches are being taught in the same school year. However, in this lesson, we will focus on how you should deliver Biology topics among learners in the secondary level. To make students’ learning more authentic, they should be taught in a way that Science, citizenship, and sustainable development are tackled at the same time. This may tell us that our teaching should be guiding principles to inform action (Howe et al., 2017). Going out of the classroom is one of the most obvious learning activities that would involve students in learning outdoor while they’re using multisensory faculties such as in an activity called “earthwalks” which requires both kinesthetic and emotional levels of the students. You may introduce sustainable development by presenting the following text from Earth Charter (www.earthcharter.org): Earth, our home, is alive with a unique community of life. The forces of nature make existence a damaging and uncertain adventure, but Earth has provided the conditions essential to life’s evolution The resilience of the community of life and the well-being of human depend upon reserving a healthy biosphere with all its ecological systems, a rich variety of plants and animals, fertile soil, pure waters, and clean air. The global environment with its finite resources is a common concern of all peoples. The protection of Earth’s vitality, diversity, and beauty is a sacred trusts. From the above Earth Charter, there are four principles as follows: 1. Respect Earth and life in all its diversity; 2. Care for the community of life with understanding, compassion and love. 3. Build democratic societies that are just, participatory, sustainable and peaceful; 4. Secure Earth’s bounty and beauty for present and future generation. Thus, we should teach our students in a way that helps them understand and appreciate the beauty and complexity of living things and their habitats.  2 2 | The Teaching of Science 20 2.1.1 Teaching in Biology through Cross-curricular Opportunities & Use of Appropriate Instructional Materials (IMs) In as far as Biology is concerned, at first what you may do is let students grasp under- standing of the key concepts in Biology and later engage them in activities which help them elaborate and apply their knowledge about those concepts. Some examples include the following (Howe et al., 2017): 1. Students can apply their knowledge about living and non-living things if you will ask them to collect and classify these things, the possible way they can; 2. Students can compare and contrast seasonal change if they will be allowed to share their own understanding about their own experience in a winter or summer; 3. Students may be asked to illustrate a food chain and they should give emphasis on arrow direction indicating matter ad energy flow from producers to consumers. They may also refer humans as part of the food chain being the consumers; 4. Students may apply their knowledge and would acquire better understanding of microorganisms if they will share their own observation on a spoiled food and relate spoilage to the growth of microbes. Aside from this, they may also share what their parents tell them when they are asked to practice good personal hygiene; 5. Students may grasp an understanding of adaptation and evolution if they will be asked of the following: a. Where do plants and animals live? b. Why do they live there? c. What kind of living things can thrive in a certain habitat? Why? 6. We may ask students to look at plants available in the market or go to a garden or farm or have a classroom display of plants. In this way, they may have exploration of the structure plants and from there, we may integrate the key concepts on seed development, photosynthesis and plant growth; 7. We may be able to teach well our students about the levels of biological organization by asking them to describe their own body structure and let them explain their own observation on the functions of these body structures; 8. Growth and reproduction can be understood by our students by asking them the following questions: a. What makes you grow? b. Have you changed since you were born? c. What changes do you observe among people as they age? 9. We can help our students to have better understanding of the application of the key concepts of biology if we would introduce them medicine and other related industries.  3 2 | The Teaching of Science 21 According to the research Igiri and Effiong (2015), the use of IMs aid teachers to make teaching biology real and permanent and the proper presentation of good IMs the way teachers employ them in the instruction enhance the understanding of the subject matter being taught. Table 2. Some IMs used in Teaching Biology IMs Description When to use/importance Is a replica of something** Models are used so students may form concepts in their minds about the subject matter at hand** They are used to provide students with nonverbal ways Models* A simplified representation of a to express understanding; when consistently used, more complex system *** models give students practice and confidence in speaking to explain their observations*** Are ideal visual aids because they are reality which are Objects** It is the thing itself or a realia used whenever possible to obtain so students can have direct contact with them during laboratory or study** A sample or part of an Excellent visual aids used to present a sample of part of Specimens** object**** the whole object** A visit to a museum can be done when we want our students have first hand observation of cultural heritage A place where objects are and other symbolic objects to expand students’ world Museum** exhibited***** knowledge and when we want to teach critical thinking, empathy, and disposition among our students******* A graphic representation show- These are best used in class when students need to focus ing information in a simple way Charts* only on the most important infographics and make which often use lines and interpretations. curves.****** Are photographs or tools that They are used to display projects, develop research or a Posters*** enable visualization in the particular perspective for class to consider****** classroom****** A representation on a flat This is used in biology class when students need to spot Maps*** surface of the whole or part of specific places or need to be guided during a field trip an area***** Is a spherical or rounded repre- Just like maps, globe can be used by students when they Globe*** sentation of the earth, a celestial need to spot places or look into the globe lines while body or heavens***** studying them Are real specimen of a Preserved particular organism that is Ideally, they can be used during laboratory activity that specimen* preserved using formalin or required dissection alcohol An instrument that produces This is basically used when students need to observe Microscope* enlarged images of small specimens that cannot be seen by unaided eye objects or specimen******** Sources: *Olangunju (2000); **Heiss (1938);***Igiri and Effiong (2015);****Bryce et al(2015); *****Cambridge dictionary (n.d.); ******Manarin (2016); *******Shulman (2013); ********Shreiber (2020)  4 2 | The Teaching of Science 22 Table 2. Some IMs used in Teaching Biology (cont.) IMs Description When to use A set of tools and apparatuses used for growth of desired organisms, usually microbes; the set Can be used when students need to Culture includes test tubes, petri dish, growth culture microorganisms for study in equipment* mediums (both and liquid), inoculation loops, their laboratory activities or research pipettes and tips, incubators, autoclaves, undertaking laminar flow hoods and microscope** Used to exemplify scientific concepts Are representation of situations or processes thereby allowing students to explore by means of something analogous. They may the nature of things*** Simulations* be computer simulations to represent the real Also helps improve students’ learning world*** by trying ideas, changing variables and run hypothetical experiments**** Sources: *Olangunju (2000); **labcompare (2020); ***Fleming (2018);****Baybe (1989) CLASS PARTICIPATION DIRECTIONS: Choose one from the application activities below. Your option should complement the available learning resources you have. Please use a SCRATCH PAPER for your task accomplishment. A. Choose appropriate learning opportunities and IMs that will match your topic discussion based on your option under ‘Let’s Do This’ activity in page 35. You may select as many as you want. Explain their congruency by writing at most 5 sentences for each. B. Interview 2 Junior or Senior High school students in you neighborhood. Ask them if they are familiar with the IMs presented in this lesson and when and how their science teachers employ these IMs in their class. Explain how well their teachers know when to employ these IMs. Limit your answer in 10 sentences.  5 2 | The Teaching of Science 23 LET’S HAVE AN ASSESSMENT… MULTIPLE CHOICE: Choose the best answer and write your answer on a scratch paper. There may be items with more than 1 correct answer. (Graded as short quiz) 1. Teacher C wants the students to have a first hand experience of the realia to make learning authentic. Which of the following IMs should be used? a. Models b. Simulations c. Specimens d. Objects 2. The anticipation of the teacher is to let students compare and contrast seasonal changes. What is the most appropriate IMs to be used if having outdoor activity is impossible? a. Museum b. Simulations c. Charts d. Maps and Globe 3. Which among the following supports best cross-curricular opportunities as applied in teaching biology concepts? a. Teachers of the same field will be having a symposium where students can listen to a speaker who will talk about their own field of specialization b. Students may be given the opportunity to work with students coming from different programs and design a collaborative work to be implemented later. c. Teacher L is a PE teacher currently working with a MAPEH teacher to plan for the best opening salvo that their students will perform in the coming charter day. d. A group of student-researchers are tasked to deal with the achievement levels of student-respondents in their program. 4. Simulations are used to exemplify scientific concepts thereby allowing students to explore the nature of things. a. True b. False c. Sometimes true d. Wrong 5. Teacher A want her students to observe minute things and will ask them to illustrate their observation during the laboratory reporting session. Which of the following is the most appropriate IMs to be used? a. Microbiology equipment c. Microscope b. Preserved specimens of microbe d. Microscope and specimens SCORING GUIDE: Each correct option is 2 points  6 2 | The Teaching of Science 24 2.1.2 Working Scientifically Perhaps the easiest way to let students work scientifically is to engage them in practical activities. For instance, if the subject matter is the needs of life, students may be provided with opportunities to learn the needs of life: air (oxygen), water, and habitat, learners may have encounter with pets, visit a zoo and ask people who look after them. However, teachers need to ask consent from the parents of there students (Howe et al., 2017). Students may also be given chances to learn how to use survey tools to apply some techniques as shown in the following table. Table 3. Ideas for Ecosystem Surveys Type of Example of Activities Outcomes Learning Outcomes Survey Descriptive Make an annotated  A collection of sketches that Students will find out about the sketch of the ecosys- can be made into a book for different kinds of living things in tem including plants, students to compare the environment, identify animals soils etc. similarities & differences between Note the ‘good’ and  A list of like & dislikes local environments and ways in ‘bad’ aspects of the about the environment from which these affect the living environment the students’ perspective things found there. Spatial Use simple mapping  A scale plan & cross section techniques to make a of the ecosystem Students will identify similarities plan & cross-section of  A wall display of the plan or & differences between local envi- the ecosystem on cross section e.g. ‘our pond’ ronments and ways in which which the position of showing above and below these affect the living things the different types of ground and water level found there. living things can be plotted Physical Use of scales or meas-  A list of abiotic factors of the uring devices, includ- ecosystem. Notes about how ing data-loggers, to wet or dry the soil was in record the factors and different areas. Graphs or Students can analyze the abiotic gradients of the physi- contour maps showing key factors in the local environment cal environment such measurements as wind, temperature, light, and sound levels Numerical Use of sampling tech-  A pyramid of numbers niques to estimate the showing different popula- Students will identify similarities populations of differ- tions of living things & differences in the local environ- ent species. Use metre- ment  A food chain showing the square quadrat, repeat relationship between living Students will learn the feeding and multiply until things found in the habitat relationships in a habitat estimated population is found  7 2 | The Teaching of Science 25 Table 3. Ideas for Ecosystem Surveys (cont.) Type of Example of Activities Outcomes Learning Outcomes Survey Temporal Study a plant and how it  A ‘tree diary’ from wet to changes over time dry season. A set of photo- Students will learn about Study an ecosystem over graphs & captions showing the seasonal changes and time, making a record of its changes in the environment how it affects the appearance, the weather, & populations during a populations and living things to be seen school year Managerial Interview adults how the Students will learn to ecosystem is cared for and  A fact-like presentation discuss & consult with managed. Find out what dossier that can be present- different members of the information exists about the ed to the school administra- school community. They ecosystem that would be tors or parent-teacher will learn to work in useful to help maintain & association about a local groups, to democratically improve the biodiversity of environment & what needs agree priorities for to be done to improve it. the ecosystem change. Source: Howe et al. (2017) Students may also conduct other activities requiring scientific inquiries and research skills where they can apply the integrated science process skills often regarded as ‘scientific method’.  Formulating Hypothesis. Stating the proposed solutions to a problem or expected outcomes for experiments.  Identifying Variables Stating the changeable factors that can affect an experiment. It is im- portant to change only the variable being tested and keep the rest constant. independent variable: a factor that is manipulated in an experiment dependent variable: a factor that is test- ed/measured to determine its response controlled variable: a factor that is kept constant in an experiment  Defining Variables Operationally. Explaining how to measure a variable in an experiment.  Describing Relationships between Variables. Explaining relationships between the inde- Source: Lancour (2009) pendent and dependent variables.  Analyzing Investigations and their Data. Inter-  Experimenting. Carrying out an experiment by preting data, identifying errors, evaluating the hy- carefully following directions of the procedure pothesis, formulating conclusions, and recom- so the results can be verified by repeating the mending further testing where necessary. procedure several times.  Understanding Cause-Effect Relationships.  Acquiring Data. Collecting qualitative and Providing reasons on what caused to what happen quantitative data as observations and measure- and why. ments.  Formulating Models. Recognizing patterns in data  Organizing Data in Tables and Graph. Mak- and making comparisons to familiar objects or ing appropriate data tables and graphs for data ideas.  8 2 | The Teaching of Science 26 CLASS PARTICIPATION DIRECTIONS: Analyze each statement and determine if it is TRUE or FALSE. Explain your answer in 2 sentences for each item. 1. In a managerial survey, students will be able to work with different members of the school community and discuss things democratically. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ___________________________________________. 2. Students may conduct temporal activities to learn about seasonal changes in a lo- cal environment. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________. 3. Students may observe working scientifically by performing science integrated process skills all the time. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________. 4. Correct identification of variable greatly affects the entire scientific investigation of a particular subject matter or study. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________. 5. Physical survey is appropriate when simple mapping technique can be applied to a scientific activity at hand. __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________. SCORING GUIDE: Each correct answer is 1 point plus 2 points for a concise and error free grammar and spelling explanation.  9 2 | The Teaching of Science 27 2.1.3 Classroom Management and Assessment of Learning In as much as we would like our students to learn best when having outdoor activities, we also need to ensure to reduce the risk because while we know that working outside is rewarding, there are unpredictable circumstances (Howe et al., 2017). We need to consider the ‘adult-to-child ratio’ which should be 1:6 if the class is outside the school premises. You may also want to have an ocular visit to the site to have a risk assessment and seek advice from the supervisor, and adults should be oriented about the possible risks and how to control them (Howe et al., 2017). If it is impossible to continue with the outdoor activities, perhaps simulations and videos would be an alternative and continue the learning process. Table 4. Risk Assessment when Working Outdoor Hazard Action to reduce risk Sharp items/syringes You have to check the general condition of the site. Use disposable gloves for in leaf, litter/ collecting from the ground. In the event of a cut, inform parents as soon as undergrowth possible. Students must be reminded about the appropriate behavior. Falling into pond Adult to control access to pond unless students are deemed responsible and capable of dealing with an accident. Consult doctor immediately in the events of student swallowing pond water. Allergic reaction to found material/ Ensure data on students’ known allergies is collected and checked and prescribed animal (most likely medication is available. Students at risk could use gloves and keep specimens in manifest hives/rash or plastic bags. breathing difficulty) Cuts caused by garden Demonstrate to students how to use tools properly. Clean tools afterwards. tools In the events of a cut, inform parents as soon as possible. Insist that students should wear long trousers and closed shoes in areas likely have ticks. Tick bites In the event of a bite inform parents as soon as possible. It is advisable to remove the tick with tweezers or tick puller. Lyme disease is a potential further risk. You should consult a doctor and told about the bite if the students begins to feel Source: Howe et al. (2017) unwell in the coming days. In addition, teachers also need to address concerns while teaching sensitive issues be- cause Biology topics also deal with issues like sex and illegal drugs. Teachers should en- sure the practice of implementing policies when teaching these sensitive issues. This im- plies that parents should be informed about what is happening in the classroom. There should be an emphasis that sex has a clear moral position, seen in the context of a stable relationship and marriage (Howe et al., 2017).  10 2 | The Teaching of Science 28 Furthermore, when you want your students conduct activities that involve laboratories, it is apparent that timing and preparation of resources is important. Therefore, whenever you plan for related activities, you have to plan how and when to access the resources, or think if they are really accessible to you (Howe et al, 2017). Have a trial to check if the materials and other tools are properly functioning and if there are no damages which may cause hazard to students. Generally, if you will be having a laboratory activities, you have to conform with the policies and guidelines for the use of the laboratory apparatuses and the use of the laboratory facility itself. Consult technician and laboratory in-charge who can guide you along the conduct of the said activities. When it comes to assessment, always remember to consider the type of assessment at hand. Recall that assessment of learning is employed after teaching when you want to have a summative assessment to know how well each student completed the learning tasks and activities to evaluate their achievement. On the other hand, assessment for learning is an ongoing assessment done to monitor students’ performance and modify and have a remedy for their learning difficulties then have a timely, specific feedback and make adjustments for their learning. Meanwhile, assessment as learning tells us that we, teachers, should help our students tap their metacognition and help them become lifelong learners. Thus, we should provide them opportunities for peer and self-assessment so they will learn to make sense of information, relate it to their prior knowledge and use it for new learning. In this way, students would develop the spirit of ownership and efficacy when they use feedback to make adjustments, improvement and changes to what they understand (Alberta.ca n.d.). To assess students’ prior knowledge, you may have ‘elicit’ activities at first where you can assess whether students have understanding or misconception of a concept in biology. From there, you may start developing learning activities that would help them understand better or correct their misconception (Howe et al., 2017). Other assessment strategies are presented below: Observation  Observation of students’ performance is an integral part of assessment. In doing so, you need to have anecdotal records because your observations can be forgotten. In this way, you will have a record of continuous progress and achievement of your students. Interviews  To assess students’ understanding, you may conduct an interview that maybe formal or informal. In this way, you are giving the students the chance to model and explain their understanding at the same time, when you pose science-related questions, you are able to focus on individual students skills and attitudes. Group/Peer Assessment  This gives students the opportunity to assess how well they work in group and reflect on one another’s work according to a clearly established criteria.  11 2 | The Teaching of Science 29 Self-assessment  This would encourage students to assess their own work. In this way, they will apply known criteria and expectations to their own work and reflect on results to determine their own progress towards a learning outcome. Performance assessment/Student Demonstration  You can assess students knowledge, skill development, and thinking process when you ask them to have a performance task such as demonstration. In this task, remember to use a scoring rubric to fairly evaluate the students’ performance. Science Journal entries  This type of formative assessment will help you assess students learning through their preferred pictures, labeled drawings, and words thus, allowing you to measure students’ depth of understanding. Rubrics/Checklist  These are used as tools to check specific process, information, and products provided by the students. They will help you describe the qualities of students’ work at various levels of proficiency for each criterion. You may develop tools like this in collaboration with the students. Visual Displays  This gives students the opportunity process information and produce a knowledge frame- work. Completed poster, concept map, diagram, model, etc., are products with which teachers can determine what students are thinking. Laboratory report  This allows you to measure students’ ability to observe, record, and interpret experimental results and further helps you to determine how well students understand the content. Pencil-and-Paper Tasks  Written tasks such as multiple choice questions, completion of a drawing or labeled diagram, problem solving, or long-answer questions, are discrete assessment tools which should be both restricted and extended. Research Repot/Presentation  This allows students to achieve the learning outcomes in individual ways. You should also remember that assessment should be built into the project at every stage, from planning to researching, to presenting finished product.  12 2 | The Teaching of Science 30 ASSESSMENT DIRECTIONS: Choose one or two scenario(s) below and write an essay with 3– 6 sentences to elaborate the idea in that item. (Graded as quiz) 1. Parents A, B and C are asking teacher M about the route and schedule of an incoming fieldtrip of their children. Teacher M has provided them the programme for the said events. 2. While preparing for the performance task to be held next week, the students of teacher C have raised their concern on the set of criteria which will be used to evaluate their performance. 3. Because Teachers Y and Z want their students to learn better about water cycle, they decided to ask from PAGASA the weather forecast in the next coming weeks. 4. Even before their laboratory class, the students of Teacher X are already oriented about the policies and guidelines on the use of their laboratory equipment and facility. 5. So students are aware of how they will be assessed and what parameters will be used in assessing them, their teacher has provided them a set of rubrics and grading system for all the anticipated assessment tasks. SCORING GUIDE: Each correct option is 2 points plus 3 points for a concise and error-free gram- mar and spelling explanation. 2.3 References Anderman, E. M. (n. d.). The Challenges of Teaching and Learning about Science in the 21st Century: Exploring the Abilities and Constraints of Adolescent Learners. The Ohio State University, 165A Ramseyer Hall, 29 West Woodruff Avenue, Columbus, OH 43210. Britannica Encyclopedia(2020). Lynn Margulis. Britannica Encyclopedia. https://www.britannica.com/ biography/Lynn-Margulis Bybee (1989). Teaching High School Biology: Materials and Strategies. NCBI. httsp:// www.ncbi.nlm.nih.gov/books/NBK218805/ Campbell, Neil A. et al. (2014). BIOLOGY 10th Edition. South Asia Pte Ltd., Pearson Educ. Campo et al. (2013). Science Learner’s Module. 1253 G. Araneta Ave., Quezon City, Philippines: Vibal Publishing House, Inc. Department of Educ. (2013). Science Curriculum Guide. DepEd Complex, Meralco Ave. Pasig City Fleming, A. (2020). Simulations for Science Education. http://ettec.ctlt.ubc.ca/510wiki/index.php? title=Simulation_for_Science_Education&oldid=64027  13 2 | The Teaching of Science 31 Igiri, C. E. and Effiong, O. E. (2015). Impact of IMs in Teaching and Learning of Biiology in Snior Secondary Schools in Yakurr LG A. International Letters of Social Humanistic Sciences, 62 27-33. https://doi.ord/10.18052/www.scipress.comILSHS.62.27 Glaze, A. (2017). Teaching and Learning Science in the 21st Century: Challenging Critical As- sumptions in Post-Secondary Science. Education Science 8 (12). doi:10.3390 educsci8010012 Gomez, M. A. (2018). Students’ Motivation toward Science Learning and Achievement in Bi- ological Sciences in a Self- Regulated Learning Environment. Journal of Education and Society Volume 2, Issue 1 , ISSN: 2619-7189. p. 10. Howe et al. (2017). Science 5-11: A Guide for Teachers Third Edition: Routledge., 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN, New York. NY 10017. labcompare (2020). Microbiology Equipment. CompareNetworks. https:// www.labcompare.com/Clinical-Diagnostics/5140-Microbiology-Equipment/ Mader, Sylvia S. and Windelspicht (2019). BIOLOGY 13th Edition. 2 Penn Plaza, New York, NY 10121: McGrew-Hill Education. Manarin, K. (2016). Interpreting Undergraduate Research Posters in the Lit. Classroom. Teaching & Learning Inquiry 4.1:1-15. Molino-Magtolis, J. B. (2013). The Use of Model Making in Teaching Human Organ Sys- tems. JPAIR Multidisciplinary Research Vol. 11, ISSN 2244-0445. doi: http:// dx.doi.org/10.7719/jpair.v11i1.197 National Geographic Society (2019). Biodiversity. Resource Library Encyclopedia Entry. https://www.nationageographic.org/encyclopedia/biodiversity/ Pearson Education, Inc. (2008). Central Dogma of Molecular Biology. Pearson Benjamin Cum- mings. Shulman, R. (2013). Why should visit museums? https://museumquestions.com/2013/ 11/07/why-should-schools-visit-museums/ Schreiber, B. A. (2020). Microscope. Britannica Encyclopedia. https://www.britannica.com/ technology/microscope Venville, G. and Treagust, D. (1997). Analogies in Biology Education: A Contentious Issue. University of California Press on behalf of the National Association of Biology Teach- ers. The American Biology Teacher, Vol. 59, No. 5. p. 286. https:// www.researchgate.net/publication/290185489 2.4 Acknowledgment The images, tables, figures and information contained in this module were taken from the references cited above.  3 | The Teaching Science in the Primary Grades 1 UNIT 3: MATTER AND ITS RELEVANCE TO HUMANS 3.0 Intended Learning Outcomes: a. Describe the role of water in sustaining life on earth; b. Illustrate the elements that play vital role in one’s life; and c. Share one’s daily experience on the necessity of water. 3.1 Introduction You know that when you are thirsty, you need water or other liquid that could satisfy your thirst. The question is, do you know why does your body need water? A plant also needs water for it to grow. You water the plants in your backyard because you know they will grow when you do so. Where do you sprinkle the water, on the plants’ leaves or in the soil where the roots are found? If you know where it should be poured, you are helping the plant then. Our lesson about water will help you explore and understand how a non-living matter contributes to the sustainability of life on Earth. 3.2 Matter and Its Relevance to Humans 3.2.1 Properties of Water that Support Life Activity: A. Stand up and ready yourself to jog or jump in place until you sweat. Record the time it took for you to sweat. While doing so, observe any change in your body temperature or wait for the sweat to come out of your skin pores. Fan yourself after doing the activity. Write your observation on the spaces provided below. Explain what you feel while you were fanning yourself. Limit your explanation in 2-5 sentences. B. Recall the days when you are cold. What do you notice on your body temperature? What happens to your skin or hair shafts? Do you know any explanation on this? Synthesize 3-5 sentences to answer the questions and write it on the spaces provided below. Water is a molecule that supports life (Campbell et al, 2014). A molecule is made up of two or more atoms which are kept together by a covalent bond. This means that the atoms in this molecule are sharing electrons in order to compose water. The atoms are hydrogen and oxygen; there are 2 hydrogen atoms and 1 oxygen atom making a molecular formula H₂O. What makes water very essential to life? The answer lies on its properties. These C. M. D. Hamo-ay  3 | The Teaching Science in the Primary Grades 2 properties of water permit life to thrive on earth, on the crust and beneath the water. These properties are dependent on the chemical bonding present in the water molecule. The illustration below will help you comprehend the chemical bonding. Figure 1. Hydrogen Bonds between Waters Molecules. The bonding shows that oppositely charged electrons are attracted to each other. Notice the V-shaped structure of the water molecule. This is due to unequal sharing of the electrons between Hydrogen (partial positive charge, δ+) and Oxygen (partial negative charge, δ-) making the bond a polar covalent bond. The result of this is hydrogen bonding among the water molecules. 3.2.2 Emergent Properties of Water As mentioned earlier, the properties of water are dependent on the boding present in it. The properties include cohesion, high specific heat, water density and water as a universal solvent (Campbell et al, 2014). Figure 2. Cohesion Cohesion is a phenomenon that kept the hydrogen bonds together (Campbell et al, 2014). This property together with adhesion (the way water molecules cling on another surface, this time on the cell wall of the water-conducting vascular tissue of a plant) help water molecules fight the pull of gravity while these molecules are climbing the vascular tissues of plant in order to reach even the highest part of which that needs water. This is very important in order for plant to transport water as it is a raw material needed in photosynthesis necessary for the plant to process its own food. The figure below illustrates the process. Another noticeable occurrence in the environment where cohesion acts on it is the capability of an organism to walk on water. Due to cohesion, surface tension in water is possible. As a result, animals like water glider and raft spider can walk on water. The figure above shows how water molecules hold each other through cohesion at the same time fight the pull of gravity through adhesion and be transported from the plant’s roots to each part of it which needs water for its survival. C. M. D. Hamo-ay  3 | The Teaching Science in the Primary Grades 3 Specific heat is the amount of heat needed to be absorbed or lost for 1 g of a substance to change its temperature by 1°C (Campbell et al, 2014). Water has a relatively high specific heat compared any other liquids. Specific heat of water is 1 calorie per gram and per degree Celsius, abbreviated as 1 cal/g ∙ °C. On the other hand, ethyl alcohol like the type of alcohol in alcoholic beverages, has a specific heat of 0.6 cal/g ∙ °C; that is, only 0.6 cal is required to raise the temperature of 1 g of ethyl alcohol by 1°C (Campbell et al, 2014). Due to this high specific heat of water, this molecule can resist the change in its temperature especially when it absorbs or releases heat. This property makes it possible for this molecule to moderate air temperature (Campbell et al, 2014). Examples of events are provided for you to better understand the concepts. A. In a smaller scale explanation, this can be observed when you boil water. It takes time for you to boil it since you still need to wait until the water reaches its boiling point, 100°C. When it boils, you see smoke coming out from the kettle which is due to breakage of hydrogen bonds. Another instance is when you sweat. Recall the activity you did before this lesson. First and foremost, you sweat because of the heat generated by your body while and after the task. The thermostat of your body raises the pressure of your body by vasoconstriction which results to the rise of its temperature and that results to production of sweat in the sweat glands. Even before the sweat comes out of your skin pores, the sweat absorbed the heat in your body. Notably, to evaporate 1 g of water at 25°C, about 580 calorie of heat is needed (Campbell et al, 2014). This means that for every 1g of sweat to evaporate from your skin pores, the temperature that your body needs to generate is 25°C. As it happens, the heat goes with the vapor resulting to the cooling effect that you feel after sweating. This is known as evaporative cooling. This is important for your body because it serves as a mechanism to prevent overheating. B. In a larger scale, a large body of water absorbs a huge amount of heat from the sun during day time. But the water heats more slowly because the water molecules can resist an immediate change of its temperature. Thus, the air it releases is cool. On the other hand, the land warms faster than the body of water. As a result, the air it releases in the atmosphere is warm. However, during at night time, the land cools faster than water. This time, the air being released by land is cool. At night, while the water cools down, the heat which was absorbed during the day, is slowly being released into the air. This is why air released from the sea is warm at night time (Pearson Education, Inc., 2014). You may notice this when you standby along the shore during the night. You would feel that the air from the sea is warm. This scenario is the so-called sea breeze and land breeze. This capability of water moderates air temperature along coastal areas. In lakes, it helps C. M. D. Hamo-ay  3 | The Teaching Science in the Primary Grades 4 such body of water to stabilize the temperature and help the organisms to survive despite fluctuation of the temperature (Campbell et al, 2014). Figure 3. Sea Breeze and Land Breeze The figure illustrates that there is warm air from the body of water that is blown to the shore during the night. Meanwhile, the air coming from the land is cooler Recall the activity you had in the previous page. The ice cubes were floating, right? Perhaps what you thought was ice must be lighter compared the water. If that’s what you thought about, you were correct! This tells you that water in solid form is less dense than in liquid form. Water density is another property of water that will help you further explain your observation. This event happens, again, due to hydrogen bonding. Once the temperature of water is above 4°C, water molecules are expanding while it warms. In contrast, the molecules contract while it cools. Once the temperature drops from 4°C to 0°C, water starts to move slowly and eventually freezes. If the temperature is 0°C, there happens the locking of the molecules by forming a crystalline lattice (see Figure 4) forming a solid matter, ice. This makes water less dense when solid and denser when liquid (Campbell et al, 2014). This property of water plays a vital role in organisms living in water ecosystems to thrive even if the atmospheric temperature drops up to the point that the water solidifies. It is very amazing to know the although there is solidification of surface water, the entire body of water will never solidify because when the surface water is in solid state it only floats while it releases heat into the liquid portion of water in order to maintain its solid phase. This is because for water to form hydrogen bond, just like when crystalline lattice forms, heat must be released. Therefore, the ice releases heat in order to keep the hydrogen bonds. Noteworthy, when the ice absorbs enough amount of heat, the ice melts because the crystals collapse turning again the water into liquid form. Moreover, it is important that ice floats since it contributes to the sustainability of life particularly in the aquatic ecosystem. C. M. D. Hamo-ay  3 | The Teaching Science in the Primary Grades 5 Figure 4. Comparison of Behavior of Water Molecules when Solid and Liquid in Form The figure illustrates that there is formation of crystalline lattice when water solidifies making the hydrogen bonds stable. Meanwhile, since water is in liquid form, the water molecules are irregular in shape and constantly forming and breaking hydrogen bonds. Still related to the chemical bonding present in water, another property of this liquid matter is due to its versatility which is directly related to its polarity making it possible to be a universal solvent. It can dissolve many substances like salt, metabolites, proteins and nucleic acids (Mader, and Windelspecht 2012). A dissolving agent is termed as a solvent while a material that is being dissolved is the solute (Campbell et al, 2014). Every time you make a coffee during your break, you are making a solution—a mixture of a solute and solvent. In this case, the warm water is your solvent while the 3-in-1 coffee powder is the solute. How relevant is this property to the existence of life on earth? First and foremost, there is life because of its building blocks. Building blocks are usually non-living in nature such as nucleotides like thymine, cytosine, adenine and guanine (building blocks of DNA), glucose (building block of carbohydrates), phosphate, together with a pentose sugar, which serve as the backbone of DNA and many other macromolecules. These are chemical structures that sustain life. Noteworthy, these biologically important chemical structures can be dissolved in water. However, not all substances can be dissolved by water. Substances can either be hydrophobic or hydrophilic. Those that are hydrophilic have affinity to water thus can be dissolved although other substances can be hydrophilic without dissolving (Campbell et al, 2014). On the other hand, those that are hydrophobic cannot be dissolved in water or they just repel with the presence of water. The different reactions of hydrophilic and hydrophobic substances to water contribute to the formation of macromolecules in a way they can support life. The following are examples: A. The phospholipid bilayer in the Cell membrane. Because its tail is composed of lipids, which is nonpolar to water, it faces another tail hiding the water environment. Meanwhile, the head that is made up of phosphorous and carbon, facing the outer C. M. D. Hamo-ay  3 | The Teaching Science in the Primary Grades 6 environment with the water. This natural structure of the phospholipid by layer, which became possible because of water, protects the cell of the organism since it has become semipermeable. This means that it does not easily allow substances to go out or get inside the cell, protecting the cell especially from substances or microorganisms that can be detrimental to the organism. Thus, contributing to its overall protection. B.