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85 Cards in this Set
- Front
- Back
Biology |
B3 |
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What is osmosis? |
The movement of water through a partially permeable membrane from a high water concentration to a low water concentration |
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Why does osmosis happen? |
Because of random movement of molecules. When molecules hit the partially permeable membrane only water will travel through because other particles are too big. |
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What does isotonic mean? |
A substance that is the same concentration as blood should be. |
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What do sports drinks contain? |
Sucrose to replace sugars lost in respiration and water and ions which are lost in sweat. |
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What is the difference between animal and plant cells when they are in a substance more dilute than the cytoplasm? |
Animal cells burst Plant cells become turgid which is good as this is what keeps the plant rigid. |
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What is the difference between animal and plant cells when they are in a substance less dilute than the cytoplasm? |
Animal cells shrink. Plant cells' membrane pulls away from the cell wall. |
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Why is the cell wall important in plant cells? |
It stops them from bursting or shrinking if they don't have the right amount of water. |
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What is active transport? |
A type of transport that moves against the concentration gradient and requires energy. |
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How is the energy for this produced? |
Cell respiration |
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How and where is active transport used in a plant? |
In root cells to absorb minerals (e.g nitrates) from liquid in soil. |
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How does active transport happen? |
Proteins in the cell membrane transport molecules from surroundings into the cell. |
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What organelle do cells which use active transport have a lot of? |
MITOCHONDRIA |
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Where are some exchange surfaces in the body? |
Lungs Intestines Kidneys |
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What adaptation does the small intestine have to help it absorb nutrients from food? |
Villi |
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What adaptation do lungs have to help them absorb oxygen and release carbon dioxide? |
Alveoli |
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What do kidneys have to get rid of urea from the blood? |
Nephrons! |
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How are villi adapted for exchange? |
Large surface area |
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How are alveoli adapted for exchange? |
Flattened cells (therefore small distance for diffusion) |
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How are nephrons adapted for exchange? |
Constant blood flow (concentration gradient is kept constant) |
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How is the small intestine adapted for exchange? |
Villi Thin walls Proteins for active transport Dense network of blood capillaries |
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Where does gas exchange happen? |
In the thousands of alveoli in the lungs |
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Where does air pass through to reach the alveoli? |
Trachea, bronchi and bronchioles |
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How are the alveoli and capillaries in the lungs adapted for gas exchange? |
They are only one cell thick so diffusion distance is short |
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How is the concentration gradient needed for diffusion maintained? |
The diaphragm and intercostal muscles relax and contract. |
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How do we breathe in? (inspiration) |
Ribs move outwards Diaphragm contracts (moves down) Intercostal muscles contract |
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How do we breathe out? (expiration) |
Ribs move inwards Diaphragm relaxes (moves up) Intercostal muscles relax |
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How are plants adapted for their needs? |
Large flat leaves to absorb light Stomata to absorb carbon dioxide Thin leaves for easy gas diffusion Root hair cells to absorb water and minerals |
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How are cells arranged in leaves? |
At the top the cells are packed together tightly to trap all of the light. In the middle there are gaps so gas can diffuse in and out of cells. |
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What is transpiration? |
The diffusion of water from the stomata |
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How does water leave the plant? |
Water moves across the cell membrane and evaporates from the cell wall. Water vapour then moves to the stomata, which may be opened or closed by the guard cells. |
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What happens when water diffuses out of the stomata? |
Water and minerals are drawn into the roots. |
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What factors increase the transpiration rate |
High temperatures (molecules have more energy) Wind (water is taken away from the leaf) Dry weather (larger concentration gradient) |
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What is a function of transpiration for plants in hot climates? |
Can act as a coolant to stop the plant from burning on hot days. |
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What are the top parts of the heart called?
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Atria!!! |
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What are the bottom parts of the heart called? |
Ventricles!!!!!!!!!!!!!!!!!! |
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What is the term for veins and arteries connected to the lungs? |
Pulmonary |
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Which side has lots of oxygen? |
The left |
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Which side has very little oxygen? |
The right |
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What does the blood leave the heart to go to the body through? |
The aorta |
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What does the blood return to the heart from the body through? |
The vena cava |
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Describe arteries |
They carry blood away from the heart They carry blood under high pressure so have thick elastic walls |
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What do coronary arteries do? |
Deliver blood to the heart |
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Describe capillaries |
They carry blood cells and are needed for transport They are one cell thick for easy diffusion |
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Describe veins |
They carry blood away from the heart They carry blood under low pressure so have valves to prevent back flow |
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What can be inserted into the coronary artery in case of cholesterol/ plaque build up? |
A stent |
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Describe plasma |
Pale yellow Carries dissolves nutrients (glucose, amino acids) And waste (CO2, urea) |
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What do red blood cells contain? |
Haemoglobin |
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What are platelets needed for? |
Blood clotting (e.g scabs) |
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What changes occur in the blood? |
Lungs exchange gas Small intestine absorbs nutrients Kidneys diffuse out urea |
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What do xylem transport? |
Water and dissolved minerals (1 direction) |
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What do phloem transport? |
Dissolved sugars (2 direction) |
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How can transpiration be measured? |
Using a photometer |
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What is urea? |
A waste product made from excess amino acids in the liver |
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What do kidneys do? |
Filter blood, absorbing everything except cells and large molecules |
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What happens to useful nutrients?
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They are re-absorbed |
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What is homeostasis? |
Keeping body levels constant (e.g temperature and water)
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How can kidney failure be treated? |
Dialysis or transplant |
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What are advantages of kidney transplants? |
If it works the patient doesn't have to use dialysis so can have a normal life. |
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What are disadvantages of kidney transplants? |
The risk of kidneys being rejected or their not being enough kidneys available. |
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What does a dialysis machine do? |
It acts as a substitute kidney, removing waste from blood. It has to be used more than once a week and doesn't cure patients. |
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What do patients with donor kidneys have to do? |
Take immunosuppressant drugs for the rest of their lives to stop their immune system from attacking the kidney. |
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What part of the brain controls temperature? |
The thermoregulatory centre |
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How does the body react to being too hot? |
Blood vessels dilate to be closer to the surface so that more heat is lost by radiation. We sweat and heat energy is used to evaporate the sweat. |
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How does the body react to being too cold? |
Blood vessels contract so that blood is kept away from the skin. Muscles contract rapidly to make us shiver, this requires energy from respiration which heats the body up. |
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What happens if body temp is too hot or cold? |
When cells are too cold, chemical reactions happen much slower. When cells are too hot enzymes can be denatured which stops reactions. |
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What happens if glucose levels are too low? |
Brain cells are affected and the person could faint. |
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What happens if glucose levels are too high? |
Water leaves the cells by osmosis and can cause permanent damage. |
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What is the role of the pancreas? |
To release hormones when blood sugar levels are too high or low. |
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What do people with type 1 diabetes have to do to maintain a healthy lifestyle? |
Eat little amounts and often
Inject insulin before meals Be careful about the amount of exercise they do |
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What is insulin? |
A hormone produced in the pancreas that tells the liver to store glucose as glycogen. |
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What is glucagon? |
A hormone produced in the pancreas that tells the liver to break down glycogen into glucose and release it into the blood. |
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What negative effect does sewage have on aquatic life? |
It lowers the oxygen concentration which kills some animals which live in water. |
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How can air be polluted? |
By smoke from fossil fuels which can cause asthma By sulfur dioxide which can cause acid rain |
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How can land be polluted |
By pesticides and herbicides |
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Why does deforestation happen? |
For timber So that land can be used for cattle, or growing crops for food or biofuel |
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Why doesn't vegetation rot in peat bogs? |
There are low oxygen levels because of the amount of water. Bacteria need oxygen to function. |
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What are some effects of climate change? |
Droughts, floods, rising sea level, extinction of species, change in migration patterns
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What is a replacement fuel for fossil fuels? |
!!!!!!BIOFUELS!!!!!! |
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What is unsustainable fishing? |
When fish are caught faster than they can breed |
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What are some ways to fish sustainably? |
Using nets with bigger holes (so little fish can get away) Imposing quotas on the amount of fish that can be caught Not fishing during breeding season |
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What is mycroprotein? |
A high protein alternative to fish and meat that can be made to look like food. (Used in quorn) |
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What fungus is mycoprotein made of? |
Fusarium |
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What is regulated when making mycoprotein? |
Ph levels Oxygen levels Temperature |
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THE |
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