Explain how the various specialized cells are modified to carry out their functions in plants and animals - KCSE biology essays

Animal cells:

Sperm cell;

Has acrosome containing lytic enzymes; that digest the egg membranes for penetration during fertilization;

Has a long tail; containing numerous mitochondria; to generate maximum energy for propulsion/swimming in the vaginal fluid after ejaculation;

Red blood cells;

Are flattened, circular/spherical biconcave in shape; to increase the surface area for packaging of haemoglobin;

Has haemoglobin; that combines with respiratory gases; for transport to and from body tissues;

White blood cells;

Are amoeboid in shape hence able to change shape; to engulf pathogens through phagocytosis;

Lymphocytes produce antibodies to fight pathogens;

Nerve cell;

Has extensions/dentrites; to receive and send information for sensation;

Ciliated epithelial cells;

Have cilia for propulsion of mucus that traps dust and micro-organisms in the respiratory tract;

Muscle cells;

Elongated, striated and contractile; to bring about movement;

Plant cells:

Guard cells;

Bean-shaped; to regulate the size of the stomata allowing gaseous exchange; and control water loss;

Has chloroplasts with chlorophyll; for photosynthesis;

Root hair cell;

Elongated; thin-walled; with dense cytoplasm for absorption of water and mineral salts;

Epidermal cell;

thin; for protection of inner tissues from mechanical and micro-organism attack;

Palisade cell;

Contains numerous chloroplasts with chlorophyll; for photosynthesis; elongated; to
increase surface area for trapping maximum amounts of light energy;

Meristematic cell;

thinwalled; with dense cytoplasm; for primary and secondary growth; Max. 20 mks