SPECIALIZED CELLS CSEC BIOLOGY 10 DM MARCH 28

SPECIALIZED CELLS CSEC BIOLOGY 10 DM MARCH 28, 2014 MRS. HAUGHTON

OBJECTIVES 1. 2. 3. 4. At the end of the class you should be able to: Identify common parts of plant and animal cells. Define the term cell specialization or cell differentiation. Recall structure and function of specialized animal cells. Identify common specialized cells found in the human body.

CELL DIFFERENTIATION Organelle cell tissue organ s ystem organism The more cells an organism has, the more complex it is. All cells start out looking the same (unspecialized) until they differentiate (have their own unique structure and function).

Cell specialization is the process which undifferentiated cells undergo in order to attain a special structure to be able to carry out specific functions in the body. Also called cell differentiation.

Both plants and animals possess their own special differentiated cells. A few of them are listed below.

INSTRUCTIONS TO TAKE NOTES For each cell: 1. Write the name of the cell as the heading. 2. In the margin, write S (for structure) then write the notes for the structure of the cell. 3. In the margin, write F (for function) then write the notes for the function of the cell. 4. Skip six (6) lines, then move on to the other cell.

SPECIALIZED ANIMAL CELLS Sperm cell Egg cell (ovum) Muscle cell Nerve cell Red blood cell (erythrocyte) White blood cell (Lymphocyte) White blood cell (Granulocyte/Phagocyte) White blood cell (Monocyte) Epithelial cells (stratified, columnar, cuboidal, squamous, ciliated, glandular)

DO THE FOLLOWING Prepare the following table. SPECIALIZED ANIMAL CELL STRUCTURE FUNCTION

SPERM CELL (structure) Consists of head, neck and tail. Head nucleus, cytoplasm and enzymes that help the sperm get into the egg. Neck contains mitochondria to give Tail energy for swimming towards the egg cell.

SPERM CELL (function) The sperm fertilizes the egg to produce an embryo (which will develop into a baby).

EGG CELL Much larger than the sperm cell. Does not move. Consists of nucleus, cell membrane, and cytoplasm containing nutrientrich yolk.

EGG CELL Fertilized embryo. by a sperm cell to form an

MUSCLE CELL Elongated cells tapered at both ends and bulging in the middle. Contains cell membrane, cytoplasm and many mitochondria for energy.

MUSCLE CELL Contract and relax to bring about movement.

NERVE CELL Extremely long. Consists of a cell body containing the nucleus. Has a long fibre called the axon which carries the nerve impulse.

NERVE CELL Transmits messages around the body in the form of electrical nerve impulses.

ERYTHROCYTE Round, tiny, elastic and flexible so that they can squeeze through blood vessels. Have a depression in the middle so are called biconcave discs.

ERYTHROCYTE Contain no nucleus or mitochondria. Consists of cell membrane, cytoplasm and a red pigment called haemoglobin which transports oxygen.

ERYTHROCYTE Transports oxygen in the bloodstream from the lungs and from cell to cell throughout the body.

LYMPHOCYTE Consists of a cell membrane, cytoplasm and large round nucleus that takes up most of the inside of the cell.

LYMPHOCYTE Secrete antibodies that destroy disease-causing organisms that invade the body.

GRANULOCYTE/PHAGOCYTE Consists of a cell membrane, cytoplasm with granules and a very irregularly shaped nucleus called a lobed nucleus.

GRANULOCYTE/PHAGOCYTE Engulfs (swallows) and destroys foreign organisms and particles that enter the body.

MONOCYTE Consists of a cell membrane, cytoplasm and a large bean-shaped nucleus.

MONOCYTE Engulfs (swallows) and destroys foreign organisms and particles that enter the body.

STRATIFIED EPITHELIAL CELLS Irregular shaped cells the upper layer of which is constantly being shed.

STRATIFIED EPITHELIAL CELLS Make up the outer layer of skin.

COLUMNAR EPITHELIAL CELLS Column-shaped cells with large nuclei.

COLUMNAR EPITHELIAL CELLS Makes up the intestinal lining.

CUBOIDAL EPITHELIAL CELLS Cube shaped cells.

CUBOIDAL EPITHELIAL CELLS Makes up outer lining of ovaries.

SQUAMOUS EPITHELIAL CELLS Irregular shaped cells that make up a very thin layer of tissue that looks like a sheet.

SQUAMOUS EPITHELIAL CELLS Makes up the lining of the blood vessels.

CILIATED EPITHELIAL CELLS Cells with fine hairs (cilia) that are located next to cells that secrete a sticky substance called mucous.

CILIATED EPITHELIAL CELLS The mucous traps invading particles and the cilia sweeps them away. Examples are found making up the inner lining of the nostrils and lining of the bronchioles (tubes found in the lungs).

GLANDULAR EPITHELIAL CELLS Consist of secretory cells which arrange themselves to form ducts or pores which secrete substances such as saliva, tears or mucous.

GLANDULAR EPITHELIAL CELLS Makes up the lining of the rectum.

SPECIALIZED PLANT CELLS

Please continue note taking as for the animal cell. Remember S for Structure and F for Function.

MESOPHYLL CELLS (S) Looks like a typical plant cells but has numerous chloroplasts.

MESOPHYLL CELLS

MESOPHYLL CELLS (F) Contain chloroplasts and so are responsible for making food for the plant by the process photosynthesis.

EPIDERMAL CELLS (S) Look like typical plant cells but do not have any chloroplasts. Cells are transparent so that light can penetrate them and get to the mesophyll cell layers beneath.

EPIDERMAL CELLS

EPIDERMAL CELLS (F) Make up the outer layer of all plant parts (leaves, stems, and roots) where it is important for protection.

ROOT HAIR CELL (S) Epidermal cells located at the plant roots. The root hair is an extension of the cell.

ROOT HAIR CELL

ROOT HAIR CELL (F) The root hair increases the surface area of the root cells for absorption of water from soil.

GUARD CELLS (S) Are special epidermal cells because they contain chloroplasts and are shaped like beans. They occur in pairs turned towards one another so that a space or pore called a stoma (plural stomata) forms between them. Are mainly located on the undersurfaces of leaves.

GUARD CELLS

GUARD CELLS (F) Control the size of the stomata by adjusting their shape. This allows more or less gases to pass into and out of the leaf when necessary.

XYLEM (S) Dead cells with thick cell walls and nothing else. Long, extremely narrow, hollow tubes formed from columns of elongated cells stacked on one another. The end walls of each individual cell have disappeared so that they appear like very long tubes.

XYLEM

XYLEM (F) Transport water and minerals from the soil and roots through the stem and to the leaves.

PHLOEM (S) STRUCTURE continued on next slide Living cells formed from long, narrow tubes formed from columns of elongated cells. The end walls have not completely disappeared. Consists of two cells: the long ones called sieve tubes and smaller ones attached to them called companion cells.

PHLOEM (S) STRUCTURE continued from previous slide Sieve tubes only have cytoplasm inside them, but companion cells contain the nucleus, cytoplasm, mitochondria that enable phloem, tissue to be living.

PHLOEM

PHLOEM (F) Transport products of photosynthesis (food) around the entire plant from leaves to growing parts as well as storage organs like fruits.

HOMEWORK You are given a sheet with fourteen specialized cells found in humans. Use the notes taken in class today in order to