AQA A-level Biology Examination

AQA A-level Biology Examination Describe eukaryotic cells - Answer- They are complex cells and include all animal and plant cells, as well as all algae and fungi cells. What does it mean if a organism is eukaryotic? - Answer- It is a multi-cellular organism that is made up of eukaryotic cells. What is an organelle? - Answer- A part of a cell that plays a specific role. Name the organelles you might find in an animal cell - Answer- 1)Plasma cell surface membrane 2)Rough/smooth endoplasmic reticulum 3)nucleus (nucleolus) 4)lysosome 5)ribosome 6)Golgi apparatus 7)cytoplasm 8)mitochondrion Name the organelles you might find in a plant cell - Answer- 1)Plasma cell surface membrane 2)cellulose wall 3)chloroplast 4)rough/smooth endoplasmic reticulum 5)mitochondrion 6)Golgi apparatus 7)vacuole 8)cytoplasm 9)nucleus 10) ribosome How are algal cells similar to plant cells? - Answer- They have the same organelles. How are fungal cells different to plant cells? - Answer- Their cell walls are made of chitin, not cellulose. They don't have chloroplasts because they don't need to photosynthesise Describe the cell surface plasma membrane. Outline the functions. - Answer- It is found on the inside of cells that also have a cell wall (plants), and is mainly made up of lipids and proteins. It controls the movement of substances in and out of the cell. It also has receptor molecules on it, to allow it to respond to chemicals like hormones. Name the components of the nucleus - Answer- 1)nucleolus 2)nuclear envelope 3)nucleoplasm 4)nuclear pores 5)chromatin Describe the nucleus. Outline the functions. - Answer- A large organelle surrounded by a nuclear envelope which contains many pores. The nucleus contains chromosomes. The nucleus controls the cell's activities by controlling the transcription of DNA. The pores allow substances to move between the nucleus and the cytoplasm. The nucleolus makes ribosomes. Describe mitochondrion. Outline the functions. - Answer- They are usually oval-shaped and have a double membrane. The inner membrane is folded to form structures called cristae. Inside is the matrix, which contains enzymes involved in respiration. The site of aerobic respiration, where ATP is produced. They are found in large numbers in cells that are very active and require a lot of energy. Describe the structure of chloroplasts. Outline the functions. - Answer- A small, flattened structure found in plant and algal cells. It is surrounded by a double membrane, and has membrane inside called thylakoid membranes. They are stacked up in some parts to form grana. Grana are linked together by lamellae. The site where photosynthesis takes place. Some parts happen in the grana, and other parts happen in the stroma. (thick fluid found in chloroplasts) Describe the structure of the Golgi apparatus. Outline the functions. - Answer- A group of fluid-filled, membrane-bound, flattened sacs. Vesicles are often seen at the edges of the sacs. It processes and packages new lipids and proteins. It also makes lysosomes. Describe the structure of a Golgi vesicle. Outline the functions. - Answer- A small fluid-filled sac in the cytoplasm, surrounded by a membrane, and produced by the Golgi apparatus. Stores lipids and proteins made by the Golgi apparatus and transports them out of the cell via the cell surface membrane. Describe the structure of a lysosome. Outline the functions. - Answer- A round organelle surrounded by a membrane, with no clear internal structure. It's a type of Golgi vesicle.