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30 Cards in this Set
- Front
- Back
Why is there a difference between heart rate for different people ?
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The fit person recovers quicker as they have a greater stroke volume, so they have a larger cardiac output and they don't respire anaerobically. |
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What happens if you have a lack of fibre?
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Peristalsis will be reduced as the muscle contractions push the fibre along the gut. Intestinal muscles will also be weaker. |
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Advantages of probiotics
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They are beneficial bacteria which replace harmful bacteria and alleviate IBS and inflammation of the intestinal wall.
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What happens after transcription and prior to translation?
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The mRNA leaves the nucleus through the nuclear membrane and attaches to a ribosome in the cytoplasm. |
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What is phagocytosis? |
Where white blood cells engulf harmful pathogens. |
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Why is the fossil record incomplete? |
We haven't found all fossils. Some fossils may be damaged. Some may be found in pieces. Soft tissue doesn't form fossils. |
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Strengths of the visking tube gut model |
Demonstrates diffusion Visking is a partially permeable membrane Demonstrates amylase Concentration gradient Water represents blood |
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Weaknesses of visking tube gut model |
Membrane not 1 cell thick Not all enzymes present No peristalsis/blood movement No villi No large surface area |
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What substances diffuse in and out of a plant? |
Water Minerals CO2 Oxygen Glucose |
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How does water travel in a plant? |
It enters by osmosis through the partially permeable wall of the root hair cell. Then, it travels through the xylem.It then evaporates from the leave through the stomata in transpiration. |
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How does glucose travel in a plant? |
It is converted into sucrose and dissolved in water. It then travels through the phloem and can travel in both directions. |
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How do minerals travel in a plant? |
They enter the plant through active transport and are then dissolved in water and travel through the xylem. They go from root to tip. |
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How does CO2 enter the plant? |
Through the stomata via diffusion. It goes from a high concentration to a low concentration, down the concentration gradient. |
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What is the formula for photosynthesis? |
water+CO2--->oxygen+glucose |
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What is the formula for respiration? |
oxygen+glucose--->water+CO2 |
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What is a polypeptide? |
A chain of amino acids |
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What does translation produce? |
A polypeptide made from amino acids |
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How does heart rate affect lactic acid? |
It doesn't, they're not related. |
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Why does concentration of lactic acid reduce when at rest? |
Because, oxygen is taken in to repay the oxygen debt. This oxygen then breaks down the lactic acid into CO2 and water, reducing levels. |
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What plant vessel would transport herbicides? |
Phloem |
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What is translocation? |
The transport of dissolved substances through a plant. |
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Characteristics of the xylem |
Made of dead cells Have a thick, strengthened cellulose wall Have a hollow lumen Travels both ways Transports water and minerals |
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Characteristics of the phloem |
Made of living cells Made of thin sieve cells Only travels one way Transports food and nutrients like glucose |
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Discovery of DNA |
Rosalind Franklin took X-Ray of DNA Watson and Crick then used this to show the helical structure and diameter. They also used their theory about AT and GC base pairings. |
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How has human genome project advanced medicine? |
Genes are being identified, so faulty genes can be spotted. People can be tested for a genetic disorder. Medicine can be personalised Gene therapy |
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What is gene therapy? |
This is where a normal allele is inserted to a chromosome to replace a faulty allele. |
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What is cardiac output? |
The volume of blood leaving the ventricle every minute. |
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What are the effects of a reduced cardiac output? |
Less blood to muscles as less is leaving heart. Less oxygen and glucose getting to muscles Less aerobic respiration Less energy Less CO2 removed More anaerobic-glucose broken down without oxygen More lactic acid |
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Why must cardiac output increase during exercise? |
So more glucose and oxygen can reach cells So more aerobic respiration can occur So more energy can be gained So more CO2 is removed Due to muscle working harder |
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Risks of cloning animals |
Larger at birth Embryo rejected Speeds up aging Smaller gene pool Genetic defects |