GenBio2 - Cell - 1st Midterm Examination PDF

ROBERT HOOKE -He was able to observe in a piece of cork specimen structures that appear as tiny compartments similar to small rooms that are fitted to each other. CELL -chamber-like structures ANTON VAN LEEUWENHOEK -Published his observations on tiny living organisms which he named animalcules....

ROBERT HOOKE -He was able to observe in a piece of cork specimen structures that appear as tiny compartments similar to small rooms that are fitted to each other. CELL -chamber-like structures ANTON VAN LEEUWENHOEK -Published his observations on tiny living organisms which he named animalcules. ROBERT BROWN -Was able to compare different kinds of plant specimens under the microscope. One common thing about them- they are all composed of cells.  NUCLEUS (dark dense spot) MATTHIAS SCHLEIDEN -Concluded that all plant parts are made of cells. THEODOR SCHWANN -Stated that all animal tissues are composed of cells. RUDOLF VIRCHOW -Concluded that all cells come from pre-existing cells. SPONTANEOUS GENERATION Living creatures could arise from non-living matter.  CELL THEORY 1.All living organisms are composed of one or more cells; 2.The cell is the basic unit of life in all living things; and 3.All cells come from pre-existing cells.  ORGANELLES They coordinate and function efficiently for the normal functioning of the cell. A few of them function by providing shape and support, whereas some are involved in the locomotion and reproduction of a cell. 9/2/2024 Sample Footer Text 15  CELL MEMBRANE Thin pliable(easily bent; flexible) elastic outermost structure which envelops the cell. 9/2/2024 Sample Footer Text 17  The plasma membrane is present both in plant and animal cells. It functions as the selectively permeable membrane, by permitting the entry of selective materials in and out of the cell according to the requirement. In an animal cell, the cell membrane functions by providing shape and protects the inner contents of the cell. 9/2/2024 Sample Footer Text 18 MITOCHONDRIA Mitochondria are called the powerhouses of the cell as they produce energy-rich molecules for the cell. They play a major role in breaking down nutrients and generating energy-rich molecules for the cell. Many of the biochemical reactions involved in cellular respiration take place within the mitochondria. 9/2/2024 Sample Footer Text 20  It is an elongated organelle enclosed by phospholipid membrane. The chloroplast is shaped like a disc CHLOROPLAST and the stroma is the fluid within the chloroplast that comprises a circular DNA. Each chloroplast contains a green coloured pigment called chlorophyll required for the process of photosynthesis. The chlorophyll absorbs light energy from the sun and uses it to transform carbon dioxide and water into glucose. 9/2/2024 Sample Footer Text 21  A tiny, circular-shaped, single membrane-bound LYSOSOMES organelles, filled with digestive enzymes. Helps in the digestion and removes wastes and digests dead and damaged cells. Therefore, it is also called as the “suicidal bags”. Lysosomes are called the suicidal bags because they are capable of breaking down or digesting all the wastes, dead and damaged cells.  Golgi Apparatus is also termed as GOLGI Golgi Complex. It is a membrane- bound organelle, which is mainly APPARATUS composed of a series of flattened, stacked pouches called cisternae. This cell organelle is primarily responsible for transporting, modifying, and packaging proteins and lipids to targeted destinations. Golgi Apparatus is found within the cytoplasm of a cell and is present in both plant and animal cells. 9/2/2024 Sample Footer Text 23  A network of ENDOPLASMIC membranous tubules, RETICULUM present within the cytoplasm of a cell. Forms the skeletal framework of the cell, involved in the detoxification, production of lipids and proteins. 9/2/2024 Sample Footer Text 24 SMOOTH ENDOPLASMIC RETICULUM 1. Ribosomes absent 2. Site of synthesis of lipid and steroid hormones. ROUGH ENDPLOPASMIC RETICULUM 1. Contains ribosomes 2. Site of protein synthesis, processing and packaging.  NUCLEUS The largest, double membrane- bound organelles, which contains all the cell’s genetic information. Controls the activity of the cell, helps in cell division and controls the hereditary characters. The nucleolus is the largest nuclear organelle and is the primary site of ribosome subunit biogenesis in eukaryotic cells. Sample Footer Text 26  RIBOSOMES Non-membrane organelles, found floating freely in the cell’s cytoplasm or embedded within the endoplasmic reticulum. Involved in the synthesis of proteins. 9/2/2024 Sample Footer Text 27  Why proteins are important in cells? Proteins are responsible for nearly every task of cellular life, including cell shape and inner organization, product manufacture and waste cleanup, and routine maintenance. 9/2/2024 Sample Footer Text 28  VACUOLE A membrane-bound, fluid-filled organelle found within the cytoplasm. Provide shape and rigidity to the plant cell and help in digestion, excretion, and storage of substances. 9/2/2024 Sample Footer Text 29 CELL TYPES  eu means “true” EUKARYOTIC karyon means “nucleus” CELLS have a membrane-bound nucleus that encloses its genetic material. found in multicellular organisms much bigger than prokaryotic cells and contain membrane- bound organelles, organized structures that perform a specific function.  pro means “before” PROKARYOTIC karyon means “nucleus” CELLS are the simplest types of cells. These are found in unicellular organisms. The DNA of prokaryotic cells is not contained within a nucleus. Instead, prokaryotic chromosomes are found in a localized area of the cell called the nucleoid region. Structure and Functions of Animal Tissues and Cell Modification Tissue is a group of cells that have similar structure and that function together as a unit.  PLANT TISSUES 1. Epidermal tissues are closely packed cells that make up the body of both non- woody and young woody plants. protective barrier against mechanical injury, water loss, and infection. 2. Ground tissues form the bulk of flowering plants. PARENCHYMA (photosynthesis in the leaves, and storage in the roots), COLLENCHYMA (shoot support in areas of active growth), and SCHLERENCHYMA (shoot support in areas where growth has ceased)is the site of photosynthesis, provides a supporting matrix for the vascular tissue, provides structural support for the stem, and helps to store water and sugars. 3. Vascular tissues transport water and nutrients within the plant as well as providing support. Xylem and phloem are vascular tissues.  Xylem tissue transports water and nutrients from the roots to different parts of the plant, and also plays a role in structural support in the stem. Phloem tissue transports organic compounds from the site of photosynthesis to other parts of the plant. ANIMAL TISSUES  Epithelial Tissue Some examples of epithelial tissue include: The outer layer of your skin (epidermis), The lining of your intestines, The lining of your respiratory tract, The lining of your abdominal cavity. Cells that make up epithelial tissues can have distinct arrangements: a. Simple Cuboidal—for secretion b. Simple Columnar—brick-shaped cells; for secretion and active absorption c. Simple Squamous—plate-like cells; for exchange of material through diffusion d. Stratified squamous—multilayered and regenerates quickly; for protection e. Pseudo-stratified columnar—single layer of cells; may just look stacked because of varying height; for lining of respiratory tract; usually lined with cilia (i.e., a type of cell modification that sweeps the mucus). Connective Tissue —most abundant and widely distributed tissue in complex animals.  —contains water, salts, and dissolved Blood proteins; erythrocytes that carry oxygen (RBC), leukocytes for defense (WBC), and platelets for blood clotting. Why blood is a connective tissue? Blood is regarded as a connective tissue because as the blood is circulated throughout the body due to pumping action of heart, it carries different materials and gases from one part of the body to another. Connective Tissue Proper (CTP) made up of loose connective tissue that is found in the skin and fibrous connective tissue that is made up of collagenous fibers found in tendons and ligaments. Adipose tissues(body fats) are examples of loose connective tissues that store fats which functions to insulate the body and store energy.  Cartilage —characterized by collagenous fibers embedded in chondroitin sulfate. Cartilage functions as cushion between bones. Bone They serve the function of making a structural framework. They connect different parts of the body.  Muscle Tissue - these tissues are composed of long cells called muscle fibers that allow the body to move voluntary or involuntary. Movement of muscles is a response to signals coming from nerve cells. a. Skeletal—striated; voluntary movements b. Cardiac—striated with intercalated disk(connect adjacent cardiac muscle cells) for synchronized heart contraction; involuntary c. Smooth—not striated; involuntary Striated muscles are highly organized tissues.  Nervous Tissue —these tissues are composed of nerve cells called neurons and glial cells that function as support cells. It is responsible for coordinating and controlling many body activities. It stimulates muscle contraction, creates an awareness of the environment, and plays a major role in emotions, memory, and reasoning. These neurons sense stimuli and transmit electrical signals throughout the animal body. Neurons connect to other neurons to send signals. The dendrite is the part of the neuron that receives impulses from other neurons while the axon is the part where the impulse is transmitted to other neurons. Cell Surface Modifications These are features or structures of the cell that makes it different from another type of cell and at the same time enables it to carry out unusual functions. Plant and animal cells are specialized to be able to carry out their tasks efficiently. They have particular adaptation to their structure to suit its function.  Cilia A cilia (singular cilium) is an organelle found in eukaryotic cells. Cilia are slender protuberances that project from the much larger cell body.  Motile cilia -are usually present on a cell's surface in large numbers and beat in coordinated waves. Function of Motile Cilia: for the transport of fluids. However, cilia are also used for locomotion (through liquids) in organisms such as Paramecium. Motile cilia are found in the lining of the trachea (windpipe), where they sweep mucus and dirt out of the lungs. In female mammals, the beating of cilia in the Fallopian tubes moves the ovum from the ovary to the uterus. Non-motile (Primary) cilia: Usually occur one per cell; all mammalian cells have a single non- motile primary cilium. Examples: sensory organs like eyes and nose Flagellum (Plural: Flagella) It is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and functions in locomotion. Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area of cells. Functions of microvilli: Absorption in intestine Secretion Cellular adhesion Examples: In sensory cells of the inner ear, in the cells of taste buds, and in olfactory receptor cells