AQA GCSE Biology - Paper 1

What does a nucleus do? - It contains genetic material and controls the activities of the cell What does cytoplasm do? - It's a gel-like substance where most of the chemical reactions happen. It contains enzymes that control these chemical reactions What does a cell membrane do? - It holds the cell together and controls what goes in and out What do mitochondria do? - These are where most of the reactions for aerobic respiration occur. Respiration transfers energy that the cell needs to work What do ribosomes do? - This is where protein synthesis takes place - where proteins are made in the cell What do cell walls do? - They are made of cellulose and they support and strengthen the cell What does a vacuole do? - It contains cell sap and helps maintain the shape of the cell What do chloroplasts do? - This is where photosynthesis occurs, which makes food for the plant. They contain chlorophyll - a green pigment - which absorbs light needed for photosynthesis What do bacterial cells contain? - Cytoplasm, cell membrane, cell wall, flagella, ribosomes, mitochondria, slime capsule, plasmids (small rings of DNA) and a single circular strand of DNA that floats freely in the cytoplasm