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37 Cards in this Set
- Front
- Back
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How is oestrogen used as a contraceptive? Whar happens if it's is taken daily? |
-Oestrogen inhibits the production of FSH so eggs do not mature, preventing egg release
- if taken every day to keep (oestrogen) levels permanently high egg development and production stops completely. |
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What does progesterone do? |
Stimulates the production of a thick cervical mucus which prevents sperm reaching the egg. |
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What two hormones does the pill contain? |
Oestrogen and Progesterone |
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Pros of the pill? |
-Over 99% effective -Reduces risk of some cancers. |
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Cons of the pill? |
-Isn't 100% effective. -Can cause side effects like headaches/nausea -Doesn't protect against STD's |
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Pros of injecting FSH and LH to increase fertility: |
Helps women get pregnant when they couldn't otherwise. |
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Cons of injecting FSH and LH to increase fertility: |
-Doesn't always work and it can be expensive to do it multiple times. -Too many eggs can be stimulated resulting in unexpected multiple pregnancies (dangerous) |
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Pros of IVF? |
Can give an infertile couple a child. |
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Cons of IVF? |
-Can have strong reaction to hormones like vomiting and dehydration -Reports of increased risk of cancer. -Multiple births (dangerous) |
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What is Auxin? |
Plant growth hormone
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What does auxin react to ? |
Light (phototropism) Gravity (geotropism) Moisture |
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What happens when plant shoots are exposed to light? |
Auxins accumulate on side in the shade.This makes the shoots grow faster on that side and bends them towards the light. |
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What do Auxins do in shoots and roots? |
Shoots: Promote growth Roots: inhibit growth Produced in the tips of shoots and roots and moves backwards to affect cell elongation just behind the tips. |
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How do shoots respond to light? |
-Auxin accumulates on the side with more shade -Cells on the shaded side elongate faster so the shoot bends upward towards the light |
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How do shoots respond to gravity? |
-Auxin accumulates on the side of gravity. -Cells on the lower side elongate faster so the shoot bends upwards. |
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How do roots respond to an uneven amount of moisture on different sides of a root? |
-Auxin accumulates on the side with more moisture and inhibits growth there -the cells on the other side will elongate faster so the root bends towards the moisture. |
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What can plant growth hormones be used for in agriculture? |
Selective weed-killers affecting only broad-leaved plants: -Broad-leaved plants = often weeds -Weed-killers disrupt their growing pattern and eventually kill them. -The crops have narrow leaves so are safe. |
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What things are controlled by homeostasis? |
Ion levels. Water levels Temperature. (Blood) sugar levels. |
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What are the 3 main ways water is lost? |
Sweat (via skin) Breathing (via lungs) Urine (via kidneys) |
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What temperature enzymes in the body work best at? |
37°C |
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Which organ controls temperature? |
Brain (thermoregulatory centre) Its sensitive to blood and skin temperature |
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What is one negative impact of steroids? |
High blood pressure. |
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What are ethical issues against taking drugs for sport? |
Unfair advantage (not from training). Athletes may not be fully aware of health risks. |
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Reasons why athletes should be able to take PED's? |
Have the right to make their own decision (if the risk is worth it). Drug-free sport isn't fair (some athletes have access to better facilities/training/coaches) |
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What do Statins do? |
Lower risk of heart and circulatory disease. Lower blood cholesterol. |
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What are the three main steps in drug testing? |
Human cells/tissues → see what it does Animal Testing → check toxicity + dosage Human testing → check for side effects + optimum dose |
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What was thalidomide originally designed for? |
Sleeping pill |
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What was thalidomide used for with negative effects? |
Morning sickness in pregnant women. |
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How many babies did thalidomide effect and how many survived? |
10,000 affected → half survived. It caused abnormal limb development |
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What is thalidamide now used to treat? |
Leprosy + some cancers. |
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The first version of the combined oral contraceptive pill contained high levels of oestrogen and progesterone. What were the problems with it? |
-High levels of oestrogen were linked to side effects like blood clots -The pill now has lower levels of oestrogen so has fewer side effects |
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Why would you use a progesterone-only pill? |
It has fewer side effects, but it's not as effective. |
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Why can low FSH levels affect fertility? Why inject FSH and LH to improve fertility? |
-Low FSH levels → eggs can't mature = no eggs are released and you can't get pregnant. -FSH and LH can be injected to stimulate egg release in the ovaries |
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Describe IVF (in vitro fertilisation) |
1)FSH and LH may be given first to stimulate egg release from the ovaries 2)Eggs collected from the woman's womb are fertilised in a lab using the man's sperm 3)Embryos grown into tiny balls of cells 4) One or two embryos are transferred to the womb to improve the chances of pregnancy |
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How do roots respond to gravity
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-Auxin accumulates on the side of gravity and inhibits growth there -Cells on the top will elongate faster so the shoot bends downwards. |
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Practice question: Why is your urine a deeper colour if you exercise on a hot day? |
You lose more water through sweating and breathing (faster) when you exercise. So urine will be more concentrated = a deeper colour. |
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Describe a double-blind trial |
Two groups → one group gets a sugar pill (placebo) Both patient and doctor don't know if they're getting sugar pill or placebo |
