So tiny & yet filled with the Secrets of the Universe

Candidates should be able to: (a)identify cell structures & organelles of plant & animal cells from diagrams, photomicrographs and under light microscope using slides & fresh material treated with an appropriate temporary staining technique: chloroplasts cell membrane cell wall cytoplasm cell vacuoles (large sap-filled in plant cells, small temporary in animal cells) nucleus (b) identify membrane systems & organelles from diagrams & electron micrographs: endoplasmic reticulum mitochondria Golgi body ribosomes

(c) state functions of the membrane systems and organelles identified above. (d) compare the structure of animal & plant cells. (e) state the relationship between cell function and cell structure for the following: absorption – root hair cells conduction and support – xylem vessels transport of oxygen – red blood cells (f) differentiate cell, tissue, organ and organ system.

» Cell membrane » Nucleus » Mitochondria » Endoplasmic Reticulum » Vacuole » Cytoplasm » Ribosomes » Golgi Body

» Cell membrane ˃Partially permeable (only some substances pass through) ˃Double phospholipid layer membrane ˃Controls movement of substances in & out of cell » Nucleus ˃Controls cellular activities (repair, growth, division) ˃Chromatin threads contain hereditary DNA (Deoxyribonucleic acid) » Vacuole ˃Contains water & food substances » Cytoplasm ˃Jelly-like fluid contain enzymes & organelles (specialised structures) ˃Site where most reactions occur

» Cytoplasm contains organelles such as mitochondria, ribosomes, endoplasmic reticulum & Golgi body. ˃Mitochondria (Power station) +Releases energy for cell activities during aerobic respiration ( Glucose + O 2  CO 2 + H 2 O + energy) ˃Ribosomes +Synthesis of proteins within the cell ˃Endoplasmic Reticulum +Smooth & Rough ER (lined with ribosomes) +Synthesis of proteins, lipids and other cellular substances ˃Golgi body +Secretion of protein +Processes & packages proteins

» It is an organelle that functions to release energy within the human body. » It is a POWER STATION for all living organsims! » The formula that you need to know.

» Similar to an animal cell » Differences ˃Cell Wall +Non-living +Fully permeable +Made of cellulose +Gives a fixed shape +Protects from injury ˃Larger vacuole sap filled +Contains cell sap rich in sugar, mineral salts & amino acids. ˃Chloroplast +Contains chlorophyll that traps light energy +Site of photosynthesis (CO 2 + H 2 O  Glucose + O 2 )

» Draw with pencil (easily to be erased) » Draw big and clearly » No shading » No double lines » No fine lines » Label parts of the diagram » Label with straight lines

» Chloroplast » Cell wall » Vacuole

» Sometimes the cell is not enough to carry out more specific functions. ˃Transport of oxygen ˃Absorption of water & mineral salts » Thus, the average cell does develops into a more complexed structure to enable them to carry out specific functions. » Process whereby a cell becomes specialised for a specific function. ˃Red Blood Cell ˃Root Hair Cell ˃Xylem

21 » Red Blood Cells (Erythrocytes) ˃Transport oxygen from lungs to all cells in the body (HBO) ˃Circular, flattened biconcave disc (increases cell’s surface area to volume ratio) ˃NO NUCLEUS (more space to carry oxygen) ˃Contains haemoglobin (carries oxygen) ˃Elastic – able to squeeze through small blood vessels ˃Formed by bone marrow ˃Lasts 3-4 months

» Cell has a long and narrow elongation » Increases surface area to volume ratio » More water and mineral salts can be absorbed from the soil

» Long hollow tubes » Transports water and mineral salts from roots to leaves » No protoplasm or nucleus ˃Hollow lumen ˃Allow more substances to be easily transported » Contains lignin (dead) ˃Strengthens the walls ˃Prevents xylem vessels from collapsing ˃Provides mechanical support

» Cells  Tissues  Organ  Organ System » Tissues ˃Group of similar cells performing the same function (muscle, RBC’s) ˃Simple – one type of cells ˃Complex – more than one type of cell » Organs ˃Several tissues work together for a specialised function. (lung) » Organ System ˃Several organs working together +Circulatory System – Lungs, Heart +Digestive System