National 5 Biology Revision

National 5 Biology Revision Where are nuclei found? ️️In the cells of green plants, animals and fungi. Describe a nucleus's appearance. ️️Large, normally spherical structure containing thread like chromosomes. What is the function of a nucleus? ️️To control a cell's activities and passes information from cell to cell and genetic information (including DNA) from generation to generation. Where are cell membranes found? ️️In the cells of green plants, animals and fungi. Describe a cell membrane's appearance. ️️A thin layer surrounding the cytoplasm. What is the function of a cell membrane? ️️To control the passage of substances into and out of the cell. Where are mitochondria found? ️️In the cells of green plants, animals and fungi. Describe a mitochondria's appearance. ️️One of many, tiny, sausage like structures containing enzymes. What is the function of mitochondria? ️️Aerobic respiration. Where are large central vacuole found? ️️In the cells of plants and fungi. Describe a large central vacuole's appearance. ️️Fluid filled sac-like structure in cytoplasm. What is the function of a large central vacuole? ️️Stores water and solutes as cell sap and regulates water content by osmosis. Where are cell walls found? ️️In the cells of green plants, fungi and bacteria. Describe a cell wall's appearance. ️️Outer layer made up of basket like structure of fibers (structure and composition of cell wall of fungi and bacteria differ from that of green plant cells) What is the function of a cell wall? ️️To support the structure of a cell Where are Chloroplast found? ️️In the cells of green plants only. Describe a Chloroplast's appearance. ️️One of many discus-shaped structures containing chlorophyll. What is the function of Chloroplast? ️️Photosynthesis Where are Circular chromosomes found? ️️In the cells of bacteria only. Describe the appearance of Circular chromosomes. ️️Single ring of genetic material. What is the function of Circular chromosomes? ️️Control cell activities and pass genetic information from cell to cell. Where are Plasmids found? ️️In the cells of bacteria only. Describe a Plasmid's appearance. ️️One of several tiny rings of genetic material. What is the function of a Plasmid? ️️To control cell activities and pass genetic information from cell to cell. Where are Ribosomes found? ️️In ALL cells. Describe a Ribosome's appearance. ️️One of many tiny particles lacking membrane boundary. What are organelles? ️️Tiny structures found within a cell's cytoplasm that are usually surrounded by cell membrane and have a specific function within the cell. Define the term 'Ultra-structure'. ️️The tiny structures within a cell. What are Lipids? ️️Fats or oils of fats found and glycerol What is meant if a cell is 'selectively permeable'? ️️The property of a cell membrane that controls the movement of molecules between cells depending on their size. What is 'active transport'? ️️The transportation of molecules against their concentration gradient from a region of low concentration to high concentration Define 'concentration gradient'. ️️The difference in concentration between two solutions, between two cells or between cells and a surrounding solution. What is 'Diffusion'? ️️The passive movement of molecules from high concentration to low concentration until they are evenly spread. What is 'Osmosis'? ️️The movement of WATER MOLECULES between a region of low soluble concentration and high soluble concentration. What is 'Passive transport'? ️️The movement of molecules down a concentration gradient without the need for additional energy e.g. diffusion and osmosis. What name is given to the basic units of life that can lead an independent existence? ️️Cells Name the 4 structural features that a typical plant cell and a typical animal cell have in common. ️️Cell membrane Ribosome Nucleus Mitochondria Identify 3 structural features present in an Elodea leaf cell but absent from a cheek epithelial cell. ️️Chloroplast Cell Wall Large central vacuole Express 1 milimetre in micrometres. ️️1000 mircometres Name 2 types of molecule present in the cell membrane. ️️Lipids and Proteins Which of the molecules present in the cell membrane is destroyed at 70 degrees Celsius? ️️The Proteins Name two essential substances that enter an animal cell by diffusion. ️️Oxygen and glucose Name a waste material that diffuses out of an animal cell. ️️Carbon diox