2nd Quarter Life Science (Week 1-2) PDF

**2^nd^ QUARTER: LIFE SCIENCE** **WEEK 1-2: INTRODUCTION TO LIFE SCIENCE** **BIOLOGY** is the scientific study of life. This comprises number of disciplines such as biochemistry and ecology. As a wide-ranging and complex science, biologists designed the term "unifying themes", which serve as the b...

**2^nd^ QUARTER: LIFE SCIENCE** **WEEK 1-2: INTRODUCTION TO LIFE SCIENCE** **BIOLOGY** is the scientific study of life. This comprises number of disciplines such as biochemistry and ecology. As a wide-ranging and complex science, biologists designed the term "unifying themes", which serve as the bases for the study of life. **[LESSON 1: EARLY FORMS OF LIFE]** - Evidences from fossil records show the emergence of the different life forms. - The common ancestor of all life was **prokaryotic.** - Since, oxygen was scarce on the early Earth, so the ancestral cell must also have been an **anaerobic.** - At present, the oldest cell **microfossils** (microscopic fossils) are filaments from 3.5 billion-year-old rocks in Western Australia. The filaments resemble chains of modern photosynthetic bacteria and the rocks in which they occur are the remains of ancient **stromatolites.** - The evolution of life is brought about by the changes in the environment which are linked to changes in climate and geology. - Evidence that life evolved is found in fossil records and molecular biology. [**LESSON 2: PROPERTIES OF LIFE** ] **1. [Order/High Degree of Organization]** --- the highly ordered structure that typifies life. **2. [Reproduction]**---the ability of organisms to reproduce their own kind. **3. [Growth and development]**---consistent growth and development controlled by inherited DNA. **4. [Energy processing]**---the use of chemical energy to power an organism's activities and chemical reactions. **5. [Response to the environment]**---an ability to respond to environmental stimuli. **6. [Regulation and Homeostasis]**---an ability to control an organism's internal environment within limits that sustain life. **7. [Evolutionary adaptation]**---adaptations evolve over many generations as individuals with traits best suited to their environments have greater reproductive success and pass their traits to offspring. 8\. [Diversity and Unity] -- evolution accounts for both the diversity and the unity of life. **THEMES ON LIFE** 1. All levels of life have systems of related parts. - A system is an organized group of interacting parts. - A cell is a system of chemicals and processes. It is the basic unit of life. - A body system includes organs that interact. - An ecosystem includes living and nonliving things that interact. **Successive Levels of Biological Organization** - Life can be studied at different levels, from molecules to the entire living planet - The study of life can be divided into different levels of biological organization - Biological organization unfolds as follows: - **Biosphere**---all of the environments on Earth that support life. - **Ecosystem**---all the organisms living in a particular area and the physical components with which the organisms interact. - **Community**---the entire array of organisms living in a particular ecosystem. - **Population**---all the individuals of a species living in a specific area. - **Organism**---an individual living thing. - **Organ system**---several organs that cooperate in a specific function. - **Organ**---a structure that is composed of tissues and that provides a specific function for the organism. - **Tissues**---a group of similar cells that perform a specific function. - **Cells**---the fundamental unit of life. - **Organelle**---a membrane-bound structure that performs a specific function in a cell. - **Molecule**---a cluster of small chemical units called atoms held together by chemical bonds. - **Atom** -- the smallest particle of an element. - **Emergent properties** result from the arrangement and interaction of parts within a system. 2. Structure and function are related in biology. - Structure determines function. - The structure is the shape of the object. - The function is the object's specific role. 3. Organisms must maintain homeostasis to survive in diverse environments. - Homeostasis is the maintenance of constant internal conditions. - All living organisms must live in a stable environment. 4. Evolution explains the unity and diversity of life. - Evolution is the change in living things over time. The genetic makeup of a population of a species change. - It accounts for both the diversity and the unity of life. 5. Traits are being inherited and transferred. - The continuity of life depends on the inheritance of biological information in the form of DNA molecules. - The genetic information is encoded in the nucleotide sequences of the DNA. 6. Organisms reproduce. - It is necessary part of living; process of making more of one's own kind. 7. Organisms are interdependent with one another. - Organisms have evolved to live and interact with other organisms. - Ecology deals with the interactions of living organisms with one another and their environment. 8. Organisms acquire and process energy. - Living organisms use a source of energy for their metabolic activities. - Some living organisms capture the light energy and convert it into chemical energy in food. - Some living organisms use chemical energy stored in molecules obtained from food. 9. Scientific Inquiry - The process of science includes observation-based discovery and the testing of explanations through the hypothetic-deductive. - Scientific credibility depends on the repeatability of observation and experiments. 10. Science, Technology and Society - Many technologies are goal-oriented applications of science. - The relationships of science and technology to society are now more crucial to understand than ever before. **WEEK 3: The Reproduction of Animals** **[REPRODUCTION]** - is one of the characteristics of life. - is the process of producing individuals of the same kind and to provide the continued existence of a species. - It may be sexual or asexual type of reproduction. - There are two types of reproduction that exists in living organisms: asexual and sexual reproduction. **Asexual reproduction** is common among lower form of animals while **sexual reproduction** can be found in more complex animals.  **[Asexual Reproduction]** - This type of reproduction does not need two parents to produce an individual. Therefore, the offspring produced is the exact copy of the parent animal. - The offspring produced through asexual reproduction is called CLONE. - Most common forms are fission, fragmentation, and budding. **1.** Fission **--** is the separation/division of an organism to form individuals of approximately same size. This is usually observed in animal like protists. - **2 Types of Fission:** a. **Binary Fission** is a type of asexual reproduction wherein two individuals will form as the parent divides in half. Example, sea anemone& other flagellated & ciliated protozoans b. **Multiple Fission** involves the repeated division of the nucleus prior to that of the cytoplasm, which ends up producing many daughter cells. Example, Plasmodium species. **2. Fragmentation** -- the breaking of body parts into fragments, is always followed by regeneration and regrowth of lost parts. Even if the animal is broken into many pieces, each piece will grow into a new individual. Planarians as well as sponges, cnidarians, bristle worms, and sea squirts reproduce by fragmentation. **3. Budding --** is when an outgrowth called a **bud** grows and develops from the parent animal and would eventually separate to become a new individual. This type of reproduction is common in certain species of coral and hydra.  https://d14fikpiqfsi71.cloudfront.net/media/W1siZiIsIjIwMTYvMDUvMTIvMTUvNDAvMDgvZDg4OGMwN2UtOGNkOS00YmY3LWFiN2YtOWVkODUwZWViZmQ1L2ZyYWdtZW50YXRpb24ucG5nIl0sWyJwIiwidGh1bWIiLCI2MDB4XHUwMDNlIix7fV1d.png?sha=e61b3588cc129743  1\. Fission 2. Fragmentation 3. Budding **[Sexual Reproduction]** ------------------------------------- - Sexual reproduction needs two parents to produce an offspring. The combination of the genes from both parents increases the chances of species variation. Therefore, species extinction is highly unlikely. - Fertilization, the union of egg and sperm cells, [could happen internally or externally.] ### **a. External Fertilization** - In external fertilization, the union of egg and sperm occurs outside the female reproductive tract. - This is common among most species of bony fish and amphibians. - As shown in the illustration below, the clasping of the male frog induces the female to release eggs, over which the male releases his sperm. Most eggs of the amphibians develop in the water but others carry them on their back or in their vocal sacs as shown below. ### **b. Internal Fertilization** In **internal fertilization**, the union of egg and sperm occurs within the female reproductive tract. Animals that undergo in this type of reproduction produce offspring in any of the following ways: oviparity, ovoviviparity, and viviparity. - **Oviparity** -- after the eggs are fertilized internally, it would complete its development outside the mother's body. The egg would receive its nourishment through its yolk. This is found in some bony and cartilaginous fish (including clown fish and blue tangs), most reptiles, some amphibians, all birds, and a few mammals (monotremes). - **Ovoviviparity** -- the eggs are also fertilized internally and receive its nourishment through its yolk. However, eggs will complete its development within the mother. They are then fully developed when they are hatched and released by the mother. This is common in some bony fish (including mollies, guppies, and mosquito fish), some cartilaginous fish, and many reptiles. - **Viviparity** -- the eggs are developed internally and receive nourishment directly from the mother's blood through placenta rather than from the yolk. This can be found in most cartilaginous fish (including lemon sharks), some amphibians, a few reptiles, and almost all mammals including humans. **WEEK 4: Genetic Engineering and Its Applications in Reproduction** **Genetic Engineering and Biotechnology** ========================================= **Genetic engineering**  - It means modifying genes in a living organism to produce genetically modified organisms (GMOs) also known as **transgenic organisms**. - It is a modern type of genetic modification. In this process, the **gene of interest** is physically removed and placed in an organism to be modified. This method is more rapid and specific than the traditional plant breeding because a gene coding for a specific trait could be transferred to an organism. - Genetic engineering is an application of **biotechnology** which uses biological systems, processes, or organisms to create products intended to improve the quality of human life. DEFINITION OF TERMS ------------------- 1. **[VECTOR]- any carrier that transfers genetic information into a cell.** 2. **[PLASMIDS]- are small circular pieces of DNA within a bacterium.** 3. **[ALTERATION]- an act of changing something that is natural.** 4. **[TRANSGENE]- a gene that is taken from the genome of one organism and introduced into the genome of another organism by artificial techniques.** 5. **[TRANSGENIC]- it denotes an organism that contains genetic material into which DNA from another organism has been artificially introduced.** THE PROCESS OF GENETIC ENGINEERING ---------------------------------- **1. DNA Isolation** -- isolating the plasmid and gene of interest. https://d14fikpiqfsi71.cloudfront.net/media/W1siZiIsIjIwMTYvMDUvMTMvMDMvMTAvMzcvMTY0ZWM5ZTItZmIzYy00ZDNiLTg1NmQtZDg2MTIxYmI0YTIyL0ROQSUyMGlzb2xhdGlvbi5wbmciXSxbInAiLCJ0aHVtYiIsIjYwMHhcdTAwM2UiLHt9XV0.png?sha=86afb67750336426 ### **2. Ligation** (gene insertion to the plasmid) - Involves sealing the gene of interest into the plasmid after they are both cut with the same restriction enzyme. When the resistant gene is inserted into the isolated plasmid, they are cleaved using the same restriction enzyme before they are combined using DNA ligases. **Restriction enzymes** are also called **restriction endonucleases**. Once they recognize a specific nucleotide sequence, they cleave the strands.  **3.** Transformation (plasmid is placed back into bacterial cell) - plasmid is placed back into bacterial cell then cells ingest foreign DNA from the surroundings. - The recombinant plasmid would then be placed back to the bacterium in a process called **transformation**.   **4. Selection** (identification of the desired clone) - is the process where the bacteria containing the recombinant plasmid with the gene of interest is selected and will be used to integrate the gene of interest in the host organism.  As shown in the illustration above, copies of the **recombinant plasmid**--- a circular, double-stranded DNA molecule will be isolated and transferred to other organisms. Depending on the gene of interest, genetic engineering has various applications in the field of medicine, environment, and agriculture. **Current Uses of GMOs** The genes of bacteria, plants, and animals are being modified to improve the quality of human life. Depending on the gene of interest, GMOs have many uses in agriculture, medicine, and the environment. **Uses of Genetically Modified Bacteria** - ***Escherichia coli*** creates a synthetic human insulin. - **Cyanobacteria** is used to yield polyhydroxybutyrate to produce bioplastic. **Uses of Genetically Modified Plants** - **Bt corn** is a pest-resistant plant against corn-infesting larvae. - **Banana vaccine** is an edible vaccine against hepatitis virus. - **Golden rice** is a genetically modified rice that produces beta-carotene. **Uses of Genetically Modified Animals** - **Bioluminescent animals** are used to identify different types of cells to detect diseases. - Some bioluminescent animals such as glofish became novelty pets to humans. - **Fast-growing salmon** are genetically modified salmon to continually produce growth hormones. **Advantages of GMOs** The GMOs offer many benefits to mankind such as: - **Increased productivity.** This enables farmers to have higher crop yields and reduced pesticide use. (e.g. Bt corn) - **Reduced pesticide use.** Since GM crops are modified for a specific pest, the use of pesticide against that pest is reduced or removed. - **Improved nutrition like the high beta carotene content of Golden Rice.** GM crops such as Golden Rice with improved nutrition (high in beta carotene) reduces eye-related problems like blindness due to malnutrition. - **Aided disease detection.** Diseases can be identified because of protein trackers in bioluminescent animals. **Disadvantages of GMOs** GMOs also raised concerns from people because of its possible harm to the environment and mankind such as: - **Reduced biodiversity of non-damaging insects.** Pest resistant crops (e.g. Bt corn) lead to unintended harm to non-crop damaging insects such as larvae of Monarch butterflies when affected by pollen of Bt corn. - **Decreased pesticide effectivity.** Pest resistant crops seem to reduce the need for pesticide at first but it would increase later on. - **Produced allergic reactions.** Some people develop an allergic response to GM crops when exposed to them. - **Led to a higher cost for GM seeds.** Farmers buy new seeds every year. Farmers using second generation seeds would lead them to Supreme Court with a charge of patent infringement. **WEEK 5: BODY SYSTEMS** The body is made up of many, many millions of cells which you cannot see unless you use a microscope. Special cells come together to make an organ. **An organ** is a complex structure with in the body. It has a special job or jobs to do. The **body system** is a group of parts that work together to serve a common purpose. Each individual body system works in conjunction with other body system. It relies on the other systems to work well to maintain internal stability and balance, otherwise known as homeostasis. The human body and even the simplest animal are made up of several organ systems that work as one unit. The major organ systems of the body work together, either directly or indirectly, to keep the body functioning normally. The body is a chemical and physical machine. As such, it is subject to certain laws. These are sometimes called natural laws. Each part of the body is engineered to do a particular function necessary for everyday living. Every day, you use your body to do a lot of things. Because of your body, you can think, move, play and generally go about your daily activities. There are lot of things happening inside your body that make life possible. You are alive because of the many wonderful systems of organs that work together perfectly through very complex processes. These organ systems keep in touch with one another, exchanging information and working together to keep you alive. +-----------------------+-----------------------+-----------------------+ | **System of the | **Major Organ** | **Function of the | | Body** | | Organ System** | +=======================+=======================+=======================+ | **INFRASTRACTURE | | | | SYSTEMS** | | | +-----------------------+-----------------------+-----------------------+ | Muscular System | Muscles, tendons | Provides movement, | | | | support and heat | | | | production; Keeps the | | | | heart beating | +-----------------------+-----------------------+-----------------------+ | Skeletal System | Bones, cartilages, | Provides shape & | | | ligaments, bone | support; Supports and | | | marrows | protects soft tissues | | | | of the body; provide | | | | movement at joints; | | | | produces blood cells; | | | | Protects organs | +-----------------------+-----------------------+-----------------------+ | Circulatory System/ | Heart, blood vessels, | Transport oxygen, | | Cardiovascular System | blood | nutrients and other | | | | substances to the | | | | cells and transport | | | | wastes, carbon | | | | dioxide and other | | | | substances away from | | | | the cells; help to | | | | stabilize body | | | | temperature and pH. | +-----------------------+-----------------------+-----------------------+ | Nervous System | Brain, spinal cord, | Collects, transfers | | | Nerves (neurons -- | and process | | | nerve cells) | information and | | | | directs short term | | | | change in other organ | | | | systems. | +-----------------------+-----------------------+-----------------------+ | **REGULATION | | | | SYSTEMS** | | | +-----------------------+-----------------------+-----------------------+ | Immune System/ | Bone marrow, thymus | Defends against | | Lymphatic System | | microbial pathogens | | | | and other diseases | +-----------------------+-----------------------+-----------------------+ | Endocrine System | Endocrine glands: | Provides | | | pituitary, thyroid, | communication within | | | parathyroid, adrenal, | the body via hormone | | | pineal | and direct long-term | | | | change in other organ | | | Pancreas | systems to maintain | | | | homeostasis; | | | Gonads | Regulates metabolism, | | | | water and mineral | | | Thymus | balance, growth and | | | | sexual development, | | | | and reproduction | +-----------------------+-----------------------+-----------------------+ | Urinary System | Kidneys, urinary | Removes excess water, | | | bladder, ureter | salts, and waste | | | | products from the | | | | blood and body and | | | | controls pH | +-----------------------+-----------------------+-----------------------+ | Excretory System | Kidneys, anus, lungs, | Collects wastes | | | skin | produced by cells and | | | | removes the wastes | | | | from the body. | +-----------------------+-----------------------+-----------------------+ | **ENERGY SYSTEMS** | | | +-----------------------+-----------------------+-----------------------+ | Respiratory System | Nose, pharynx, | Deliver air to sites | | | larynx, trachea, | where gas exchange | | | bronchi, alveoli | can occur; Moves | | | | oxygen from the | | | Diaphragm | outside environment | | | | into the body; It | | | | also removes carbon | | | | dioxide and water | | | | from the body. | +-----------------------+-----------------------+-----------------------+ | Digestive System | Esophagus, stomach, | Process foods and | | | small intestine, | absorb nutrients, | | | large intestine, | minerals, vitamins, | | | rectum | and water. | +-----------------------+-----------------------+-----------------------+ | **OTHER SYSTEMS** | | | +-----------------------+-----------------------+-----------------------+ | Integumentary System | Skin, hair & nails | Covers and protects | | | | the body to prevent | | | | water loss and keep | | | | out foreign | | | | particles; Keeps you | | | | in touch with the | | | | environment (nerve | | | | endings); Regulates | | | | your body | | | | temperature; Gets rid | | | | of wastes | | | | (sweat/perspiration) | +-----------------------+-----------------------+-----------------------+ | | | | +-----------------------+-----------------------+-----------------------+