AQA GCSE Biology B1

AQA GCSE Biology B1 What are cells? The building blocks of organisms Define eukaryotic cell Cells that have a true nucleus Define prokaryotic cell Cells that do not have a true nucleus What is in an animal cell? Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes What is in a plant cell? Same as animal plus: vacuole, chloroplasts, chlorophyll, cell wall What is in a yeast cell? Same as animal plus: temporary vacuole, cell wall What is in a bacterial cell? Cytoplasm, cell membrane, cell wall, ribosomes, chromosomes, plasmid, capsule, flagellum Function of nucleus The control centre of the cell, contains DNA Function of cytoplasm Where chemical reactions take place Function of cell membrane Controls the flow of substances into and out of the cell Function of mitochondria Releases energy into the cell in respiration Function of ribosomes Where protein synthesis takes place Function of vacuole Keeps the cell turgid (filled with plant sap) Function of chlorophyll Absorbed light energy in photosynthesis Function of cell wall Provides structure for the cell, made of cellulose Function of chromosomes Carries genetic information Function of plasmid Carries genetic information Function of capsule Protects against phagocytosis Function of flagellum Helps the cell move Adaptations of muscle cells Contain proteins that slide over each other making fibres contract Contain mitochondria to transfer energy Store glycogen used in cellular respiration Adaptations of nerve cells Lots of dendrites to make connections to other nerve cells The axon carries the nerve impulses from one place to another and are often very long Synapses pass impulses to another cell or between a nerve and the muscle Adaptation of root hair cells Increase surface area for water to move up the cell Have mitochondria that transfer energy needed for transport of mineral ions into the cell Have a large permanent vacuole that speeds up the movement of water by osmosis Adaptations of sperm cells Long tail to whip to propel the sperm forward Middle section has lots of mitochondria which transfer energy to the tail