WEEK 2-CELL TYPES, FUNCTIONS & MODIFICATION.pptx

CELL TYPES, FUNCTIONS & MODIFICATION

1. CELL: TYPES, FUNCTIONS, AND MODIFICATION BAY-ANG MAGPAG-ONG NATIONAL HIGH SCHOOL-SHS DEPARTMENT- BIOLOGY 1

2. LEARNING COMPETENCIES  Distinguish prokaryotic and eukaryotic cells according to their distinguishing features (STEM_BIO11/12-Ia-c-3)  Classify different cell types (of plant/animal tissues) and specify the functions of each (STEM_BIO11/12-Ia-c-4)  Describe some cell modifications that lead to adaptation to carry out specialized functions (e.g., microvilli, root hair) (STEM_BIO11/12-Ia-c-5)

3. Animal tissues AND ITS four main types

4. 1. Epithelial Tissue This type of tissue is commonly seen outside as coverings or as linings of organs and cavities. It is characterized by closely-joined cells with tight junctions. Being tightly packed, tight junctions serve as barriers for pathogens, mechanical injuries and fluid loss. Cells that make up epithelial tissues have distinct arrangements:

5. A. Cuboida l- 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)

6. 2. CONNECTIVE TISSUE - Connective tissue is a diverse group of tissues that support, connect, and separate different types of tissues and organs in the body. It provides structural support, protection, and helps in various functions like nutrient transport and tissue repair.  These tissues are composed of the following: A. BLOOD- made up of plasma (i.e., liquid extracellular matrix): contains water, salts and dissolve proteins, erythrocytes that carry oxygen (RBC), leukocytes for defense (WBC), and platelets for blood clotting.

7. B. 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 are also examples of loose connective tissues that store fats which functions to insulate the body and store energy.

8. C. CARTILAGE- characterized by collagenous fibers embedded in chondroitin sulfate. Chondrocytes are the cells that secrete collagen and chondroitin sulfate. Cartilage functions are cushion between bones. D. BONE- mineralized connective tissue made by bone-forming cells called osteoblasts which deposits collagen. Blood vessels and nerves are found at a central canal surrounded by concentric circles of osteon.

9. 3. MUSCLE TISSUE These tissues are composed of long cells called muscle fibers that allow the body to move voluntary or involuntary. It gives rise to muscles' ability to contract. This is opposed to other components or tissues in muscle such as tendons or perimysium. It is formed during embryonic development through a process known as myogenesis. Muscle tissue consists of elongated cells also called as muscle fibers. This tissue is responsible for movements in our body. Movement of muscles is a response to signals coming from nerve cells.

10. In vertebrates, these muscles can be categorized into the following: Skeletal- striated: voluntary movements, attached to the skeleton Cardiac- striated with intercalated disk for synchronized heart contraction, involuntary, located in the walls of the heart Smooth- not striated; involuntary, located in walls of hollow visceral organs.

11. 4. Nervous Tissue These tissues are composed of nerve cells called neuron and glial cells that function as support cells. These neurons sense stimuli and transmit electrical signals throughout the animal body. Neurons connect to other neuron that receives impulses from other neurons, while the axon is the part where the impulse is transmitted to other neurons.

12. plant tissues AND ITS four main types

13. MERISTEMATIC TISSUE is actively dividing to produce new cells. Meristematic tissue consists of undifferentiated small cell, with dense cytoplasm and large nuclei. The cells differentiate into new tissue of the plant. Meristematic tissue is found at the meristems of plants: A. Apical Meristem - are located at the growing points at the tips of roots and stems and results in an increase in the length of these structures.

14. B. Lateral Meristem - results in the growth in thickness or width of woody roots and stems. This tissue is also called cambium; cork cambium divides to form the cork cells that form the outer bark of a woody plant. Vascular cambium divides to make xylem and phloem tissue

15. C. Intercalary Meristem -enable plants to regrow lost or damaged tissues. Contributing to their ability to recover from grazing or environmental stress.

16. II. PERMANENT TISSUE These are specialized in function and do not divide constantly. Differentiation of cells begins as soon as cells have been formed by cell division, and results in changes in structure. There are two groups of permanent tis sue:

17. 1. Epidermal Tissue - This is the outermost layer of cells that covers the roots, stems, and leaves. They are tightly packed, with no intercellular air spaces. The main function of the epidermal cells is to protect the underlying tissue from injury. Guard cells - are bean- shaped epidermal cells that occur on either side of a stoma- which is the opening that occurs on the surface of a leaf. The guard cells function to open and close the stoma, thus controlling the loss of water by transpiration. . Hair cells - are formed by an extension of the cell wall. The hair functions to increase the surface area of the root to maximize the uptake of water and nutrients.

18. 2. VASCULAR TISSUE - functions to transport and support. Xylem - transport water and mineral salts from the ground water through the roots to the stems and leaves. It consists of vessels and tracheids - both cells have cell walls that are strengthened with lignin and both types of cells are dead at maturity. Phloem - transport food from the leaves, where photosynthesis takes place, to areas undergoing growth or storage sites. Phloem tissue consists of long columns of sieve tubes and companion cells.

19. IV. GROUND TISSUE This type of tissue forms the body of the plant and is responsible for support, storage, and photosynthesis. There are three types of ground tissue: Parenchyma - thin walled and alive at maturity; often multifaceted. Collenchyma - thick walled and alive at maturity. Sclerenchyma - thick walled and dead at maturity

20. What is cell modification?

21. Cell specialization or modification occurs after cell division wherein newly formed cells are structurally modified so that they can perform their function efficiently and effectively.

22. APICAL MODIFICATION It is a cell modification found on the apical surface of the cell. Cilia and flagella ➢ Cilia are usually short, hair-like structures that move in waves. ➢ Flagella are long whip-like structures. ➢ Formed from microtubules

23. Villi and microvilli ➢ Villi are finger-like projections that arise from epithelial layer in some organs. They help to increase surface area allowing for faster and more efficient adsorption. ➢ Microvilli are smaller projections that arise from the cell’s surface that also increase surface area allowing faster and more efficient adsorption.

24. These projections increase the surface area of the small intestine for the absorption of nutrients, and as a higher surface area = higher rate of transportation processes such as diffusion, they thus increase the rate of absorption.

25. Pseudopods ➢ Temporary, irregular lobes formed by amoebas and some other eukaryotic cells ➢ Bulge outward to move the cell or engulf prey ➢ From the Greek word pseudes and podos, meaning “false” and “feet”.

26. Extracellular matrix (ECM) ➢ Compound secreted by the cell on its apical surface ➢ Cell wall in the extracellular structure in plant cells that distinguishes them from animal cell ➢ Glycoprotein is the main ingredient of ECM in animal cells. ➢ They cover external surface, line up internal organs, take up nutrients, export wastes, and interact with the external environment.

27. BASAL MODIFICATION ➢ Cell modification found on the basal surface of the cell desmosomes/hemidesmosomes ➢ Anchoring junction on the basal surface of the cell Rivet-like links between cytoskeleton and extracellular matrix components such as the basal lamina that underlie epithelia. Primarily composed of keratin, integrin, and cadherin.

28. LATERAL MODIFICATION A cell junction that provides contact between neighboring cells or between the cell and extracellular matrix. Tight Junction ➢ Acts as barriers that regulate the movement of the water and solutes between epithelial layers ➢ Prevent leakage of ECF

29. Adhering Junction ➢ Anchoring junction on the lateral surface of the cell ➢ Very similar to the anchoring junction of the basal surface of the cell ➢ Fasten cells to one another

30. Gap Junction ➢ Also known as communicating junctions ➢ Closable channel that connect the cytoplasm of adjoining animal cells ➢ Presence of connexon that allow direct exchange of chemical between the cytoplasm of the cells

31. THANK YOU!