IGCSE Topic 1: Cells & Organisms Complete Test 2024.

IGCSE Topic 1: Cells & Organisms Complete Test 2024. Cell membrane - CORRECT ANSWER Lipid layer that surrounds the cell and contains the cytoplasm. Cell wall - CORRECT ANSWER The strong structure made largely from cellulose that gives plant cells their rigidity and their ability to resist turgour pressure. Chitin - CORRECT ANSWER Carbohydrate polymer that forms the cell walls in fungi and the external skeleton of insects. Chloroplast - CORRECT ANSWER The membrane bound organelle in plants that is the site of photosynthesis. Circulatory system - CORRECT ANSWER Organ system involved in transport of materials around the body. Includes heart and blood vessels. Contractile vacuole - CORRECT ANSWER Found in freshwater protists, this organelle is important in the regulation of the organism's water content under different osmotic conditions. Cytoplasm - CORRECT ANSWER The complex mixture of enzymes and chemicals where many of the reactions of life happen in the cell. Differentiation - CORRECT ANSWER The process by which a cell becomes specialised to carry out a particular function in a multi-cellular organism. Excretory system - CORRECT ANSWER The organ system involved in excretion. Includes the kidneys, which filter toxic waste from the body, and the liver. Mitochondria - CORRECT ANSWER A membrane bound structure (organelle) within the cell where aerobic respiration takes place. Provides most of the energy for cell activity. Multicellular - CORRECT ANSWER Organisms that are composed of more than one cell are described as this.