Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
Why is there a difference between heart rate for different people ?
|
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. |
|
|
What happens if you have a lack of fibre?
|
Peristalsis will be reduced as the muscle contractions push the fibre along the gut. Intestinal muscles will also be weaker. |
|
|
Advantages of probiotics
|
They are beneficial bacteria which replace harmful bacteria and alleviate IBS and inflammation of the intestinal wall.
|
|
|
What happens after transcription and prior to translation?
|
The mRNA leaves the nucleus through the nuclear membrane and attaches to a ribosome in the cytoplasm. |
|
|
What is phagocytosis? |
Where white blood cells engulf harmful pathogens. |
|
|
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. |
|
|
Strengths of the visking tube gut model |
Demonstrates diffusion Visking is a partially permeable membrane Demonstrates amylase Concentration gradient Water represents blood |
|
|
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 |
|
|
What substances diffuse in and out of a plant? |
Water Minerals CO2 Oxygen Glucose |
|
|
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. |
|
|
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. |
|
|
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. |
|
|
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. |
|
|
What is the formula for photosynthesis? |
water+CO2--->oxygen+glucose |
|
|
What is the formula for respiration? |
oxygen+glucose--->water+CO2 |
|
|
What is a polypeptide? |
A chain of amino acids |
|
|
What does translation produce? |
A polypeptide made from amino acids |
|
|
How does heart rate affect lactic acid? |
It doesn't, they're not related. |
|
|
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. |
|
|
What plant vessel would transport herbicides? |
Phloem |
|
|
What is translocation? |
The transport of dissolved substances through a plant. |
|
|
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 |
|
|
Characteristics of the phloem |
Made of living cells Made of thin sieve cells Only travels one way Transports food and nutrients like glucose |
|
|
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. |
|
|
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 |
|
|
What is gene therapy? |
This is where a normal allele is inserted to a chromosome to replace a faulty allele. |
|
|
What is cardiac output? |
The volume of blood leaving the ventricle every minute. |
|
|
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 |
|
|
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 |
|
|
Risks of cloning animals |
Larger at birth Embryo rejected Speeds up aging Smaller gene pool Genetic defects |
