17102339
Description
Flashcards by Darcey Harvey, updated more than 1 year ago
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Created by Darcey Harvey
about 5 years ago
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| Question | Answer |
| What is the main difference between a prokaryotic cell and a eukaryotic cell? | A eukaryotic cell has a nucleus, a prokaryotic cell does not |
| What type of organisms are prokaryotes? | Bacteria |
| What is the function of mitochondria? | Aerobic Respiration to release energy |
| What do plant cells have that animal cells do not? | Cell walls, chloroplasts, vacuoles |
| How are xylem cells adapted to their function? | They are dead, hollow and strong so they can easily transport water |
| How is a sperm cell adapted to its function? | It has a tail so it can swim and many mitochondria for energy |
| What word means how many times bigger a microscope image is than its actual size? | Magnification |
| What is the formula for calculating magnification? | M = image size / actual size |
| What is the name for how bacteria reproduce? | Binary Fission |
| How many pairs of chromosomes would you find in a normal human body cell? | 23 |
| What is a chromosome made of? | DNA |
| If you wanted to grow some bacteria in the laboratory how could you make sure your plate was not contaminated? | Wear gloves/wash hands, use a Bunsen to sterilise your equipment (such as the loop), only open the lid of the plate a small amount |
| What has to happen in a cell before it can divide? | The DNA has to copy itself (replicate) |
| What is the name of the type of cell division that makes new identical cells? | Mitosis |
| Why do you need cell division to happen in your body? | To make new cells so you can grow and to replace old cells |
| What type of cells can change (differentiate) into other types of cell? | Stem cells |
| Why do some people object to using stem cells in medical treatments? | Religious and ethical objections to using stem cells from embryos |
| By what process can oxygen and carbon dioxide cross cell membranes in the lungs? | Diffusion |
| What makes diffusion occur faster? | Large surface area, higher temperature, bigger difference in concentration |
| By what process can water move across cell membranes eg in plant roots? | Osmosis |
| What process requires energy from respiration to move molecules against their concentration gradient? | Active Transport |
| What is moved into plants by active transport process? | Minerals e.g. nitrate |
| What happens to plant cells if water moves out by osmosis? | They become plasmolysed |
| What happens to animal cells if they take in too much water by osmosis? | They burst |
| What name is given to a solution with lots of solute (eg salt) in it so it has more salt than the cells present? | Hypertonic |
| What enzyme is produced by the salivary glands and what does it break down? | Amylase breaks down starch |
| Why is the stomach acidic? | It provides the optimum pH for the enzyme pepsin. It also kills bacteria. |
| What does bile do? | It emulsifies fats to increase their surface area for the action of lipase |
| What is the job of the pancreas in the digestive system? | It releases digestive enzymes |
| What are the two parts of the small intestine called? | Duodenum and ileum |
| Why does the ileum have villi? | To increase the surface area for absorption of digested food |
| What happens to enzymes if body temperature rises too high? | They start to denature at high temperatures meaning the active site changes shape |
| Why does each enzyme only work on one substrate? | The active site of an enzyme has a specific shape to fit a substrate like a ‘lock and key’ |
| What enzyme breaks down fats into fatty acids and glycerol? | Lipase |
| What are the 4 chambers of the heart called? | Right and left ventricle, right and left atrium (plural = atria) |
| What is the only artery in the body to carry deoxygenated blood? | Pulmonary artery (carries blood to the lungs to pick up oxygen) |
| What is blood made up of? | Plasma carries the red blood cells. White blood cells are platelets |
| Why does your blood need to clot using platelets if you cut yourself? | To stop bacteria entering your body and to prevent blood loss |
| Which type of blood vessel has very thin walls to allow exchange of substances with cells? | Capillaries |
| Which blood vessels become blocked leading to heart disease? | Coronary Arteries |
| Why do veins have valves? | To prevent the blood flowing backwards as the pressure from the heart is low in the veins |
| Which layer of the leaf carries out most photosynthesis? | Palisade mesophyll |
| Which layer of the leaf has air spaces for carbon dioxide to diffuse in? | Spongy mesophyll |
| What name is given to the holes in the underside of leaves which are controlled by guard cells and allow carbon dioxide into the leaf? | Stomata |
| By what process is water lost from leaves? | Transpiration |
| What is translocation? | The movement of sugars around the plant |
| How is xylem tissue adapted to its job? | The cells are hollow and their walls are very strong |
| Why is transpiration usually faster in summer in the UK? | It is warmer so water evaporates from the stomata at a faster rate as the water particles have more kinetic energy |
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