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69 Cards in this Set

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  • Back

What are the main roles of the kidneys?

1) Remove Urea from the blood

2) Adjust ion levels in blood

3) Adjust water content in blood

What do the kidneys produce?


What are the three stages for filtering blood (in the kidneys)?

1) Ultrafiltration - The small molecules are forced into the Nephron

2) Selective reabsorption - particular molecules are allowed back into the blood

3) Release of Waste products

What happens to the glucose in reabsorption in the Kidneys?

All of it is filtered back into the blood

How is water in the body controlled?

By a negative feedback loop using the hormone ADH

What does ADH stand for?

Anti - Diuretic Hormone

What happens if there is too much water in blood?

1) The hypothalamus detects the rise

2) The pituitary gland produces LESS ADH

3) Less ADH means kidneys reabsorb LESS water

4) More water is urinated out

5) Water level goes down

What happens if there is not enough water in the blood?

1) The hypothalamus detects the fall

2) The pituitary gland produces MORE ADH

3) More ADH means kidneys reabsorb MORE water

4) Less water is urinated out

5) Water level goes up

Label this image

What are the options if your kidneys do NOT function correctly?

1) Dialysis machine

2) Kidney transplant

How does a dialysis machine work?

1) Blood flows through the dialysis machine

2) The machine is full of dialysis liquid which has the same concentration of salts and glucose as blood, so they flow into the blood

3) Waste products flow out, through the semi permeable membrane.

What is the issue with kidney transplants and how can it be solved?

The body can reject them

- Always take a kidney from someone with similar tissue type

- Treat the patient with drugs that suppress the immune system so that it will not attack the kidney

What are the specialised features of an egg cell?

1) It contains nutrients in the cytoplasm to feed the embryo

2) Straight after fertilisation, the egg's membrane changes to stop any more sperm getting in (So there is the correct amount of DNA)

3) The nucleus is haploid, so the embryo has the right amount of chromosones

What are the specialised features of a sperm cell?

1) Long tails to swim to the egg

2) Lots of mitochondria so they can provide enough energy to swim that distance (from respiration)

3) The head contains acrosome to dissolve the membrane of the egg

4) The nucleus is haploid, so the embryo has the right amount of chromosones

What and When are the four stages of the menstrual cycle?

Day 1 - Uterus lining breaks down (menstruation)

Days 4-14 - Uterus lining builds up

Day 14 - An egg is released from the ovaries (ovulation)

Days 14-28 - The lining of the uterus is maintained before starting the cycle again

What are the four main hormones in the menstrual cycle?

FSH (Follicle stimulating hormone), LH (Lutensing hormone), Oestrogen and Progesterone

What are the roles of FSH in the menstrual cycle?

1) Causes a follicle (An egg and its surroundings to mature)

2) Stimulates oestrogen production

What are the roles of oestrogen in the menstrual cycle?

1) Causes thickening of the uterus lining

2) Lots of oestrogen stimulates a surge in LH

What are the roles of LH in the menstrual cycle?

1) Stimulates ovulation at day 14

2) Turns the follicle remains into a corpus luteum - which release progesterone

What are the roles of progesterone in the menstrual cycle?

1) Maintains uterus lining

2) Inhibits (stops) production of FSH and LH

3) Low levels allows lining to break down and then levels of FSH to increase

What happens to the hormones if a woman gets pregnant?

The levels of progesterone stay high, maintaining the uterus lining.

What is the purpose of the placenta?

To provide the baby with oxygen, glucose, nutrients etc, and remove waste products like urea

How are the levels of hormone controlled?

Negative feedback loop, i.e:

1) FSH stimulates ovary to release oestrogen

2) Oestrogen inbits production of FSH

What are the three main fertility treatments?

Hormone treatment, IVF (with eggs from the mother OR another mother) and surrogacy.

What does hormone fertility treatment involve?

Injection of FSH and LH into the blood can cause egg release from their ovaries in women who cannot produce enough of them

What are/is the Pros for hormone treatment?

A lot of women are helped to get pregnant.

What are/is the Cons for hormone treatment?

1) It doesn't always work, lead to some women having it many times, and it is expensive

2) Too many eggs can be stimulated, causing multiple pregnancies

What does IVF involve?

It involves collecting a woman's eggs and fertilising them with a man's sperm in a test tube and, once grown enough, the embryo is transferred to a woman's uterus.

FSH and LH are injected into the woman beforehand to produce the eggs

What are/is the Pros for IVF?

A lot of women are helped to get pregnant.

What are/is the Cons for IVF?

1) Some women react badly to the hormones

2) It is suggested the hormones MIGHT cause cancer

3) Multiple births can occur, bringing higher risk of miscarriage or stillbirth

What are/is the Pros for IVF (With eggs from another mother)?

1) A woman who cannot produce eggs can still have a baby

2) Donated eggs can prevent the passing of a genetic disorder from the mother

What are/is the Cons for IVF (With eggs from another mother)?

Families can find it difficult knowing the bay has a different genetic mother

What does surrogacy involve?

IVF is performed with the mother's eggs and the father's sperm and then this embryo is implanted in another woman's uterus. After giving birth, the surrogate mother gives the baby back to the parents.

What are/is the Pros for Surrogacy?

A woman can still have a baby is the mother can't become pregnant or it is too risky to give birth.

What are/is the Cons for Surrogacy?

The surrogate mother is technically the child's mother until it is adopted, and some mothers will not want to give the child back.

How many pairs of chromosomes does every human cell contain?

23 - 22 matched pairs and another called XX or XY

What X and Y chromosome combinations will cause a baby to be a boy or a girl?

XX - Girl

XY - Boy

What X or Y chromosomes does an egg contain?

They can only have an X chromosome

What X or Y chromosomes does an sperm contain?

Either X or Y

What is the probability that any child will be a boy, and why?

50%, 0.5 or 1/2. When the X of an egg pairs with the X from a sperm, it forms XX and therefore a woman, whilst when it pairs with a Y, it forms XY and therefore a man. Because the X or Y chromosome in sperm is equally likely, it is 50%

What does it mean if a genetic characteristic is 'Sex-linked'?

It means the allele that codes for that is found on a sex chromosome (X or Y)

Why are men more likely to suffer from sex-linked diseases than women?

As the men only have one X chromosome, which is longer, they will often only have one allele for a sex linked disease. This means it will always show itself, even if it is recessive, whereas women will often have two, meaning it is less likely they have it.

What are some examples of a sex-linked genetic disorder?

Colour blindness, Haemophilia

What does exponential mean?

It grows very fast, and the rate of growth gets faster as it progresses.

Who and when proved that microbes caused disease and how?

Louis Pasteur (19th Century)

He heated broth in two flasks and left them open, one flask with a curve in, the other not. the broth with the curve in stayed fresh as the microbes could not get in, whilst the other went off because they could, proving they existed.

What is pasteurisation and why is it better than sterilisation?

A process that involves heating something up and then cooling it, killing the bacteria. it is preferable to sterilisation because that kills of the vitamins in products too

What can you use to measure how fast microorganisms are growing and How?

Resazurin Dye - It is sensitive to oxygen, the less oxygen, the more it changes colour. As microbes respire they use up the oxygen, changing its colour, therefore the quicker it changes colour, the more bacteria there are. This allows you to see how pH or temperature affect the growth of bacteria.

What do B-lymphocyte cells do when they encounter foreign bacteria? Why?

B-lymphocytes will scan the molecules on the surface of cells. When a new antigen they do not recognise comes in, they start producing antibodies that lock onto only that SPECIFIC antigen, and then start to kill it off.

How do Lymphocytes create immunity?

1) When the B-lymphocyte has created that specific antibody, a special type of lymphocyte called a 'Memory lymphocyte' is created

2) These remember specific pathogens and can produce those antibodies quickly

3) If the same pathogen enters the body again, these memory lymphocytes quickly respond, producing many more antibodies, killing it off before it can affect you

How does immunisation work?

1) Dead of inactive pathogens (with antigens) are injected into the body

2) Your body still makes antibodies against them and memory lymphocytes are also produced.

3) If the live pathogen is in the body again, these antibodies quickly respond and kill them, making you immune

Who and How discovered immunisation?
Edward Jenner
In the 1700s, many people died from small pox, but jenner noticed those who had had COW pox would not suffer from smallpox. Therefore, he gave a boy cow pox (by putting bit of scab from a girl with cow pox into a cut), and then exposed this boy to smallpox, which he didn't catch.

What is/are the pros of immunistaion?

1) Outbreaks of diseases can be contained if a large percentage are immunised. Even people who aren't immunised are less likely to catch it, as there fewer people to pass it on

2) Some diseases have been completely eradicated by immunisation

What is/are the cons of immunistaion?

1) It doesn't always work

2) Sometimes you can have a reaction to the injection, like an anaphylactic shock

What are monoclonal antibodies and why are they useful?

Antibodies that have been made from B-lymphocytes and divide really quickly. They can be used to stick to anything you want and they will ONLY stick to this molecule

How do you make monoclonal antibodies?

1) Inject mouse with specific antigen

2) Take the b-lymphocytes created from that mouse

3) Fuse it with a tumour cell that has been grown in a lab

4) This makes a 'Hybridoma'

5) Culture this, and it will reproduce quickly

How does a pregnancy test work, and what happens if you are or aren't pregnant?

CHG is a hormone found in the urine of pregnant women.

1) The window (you look at) has antibodies for HGH stuck fast to it and the bit you wee on has more antibodies stuck to blue ink beads

2) If you ARE pregnant, the CHG in urine sticks to the antibodies attached to the blue beads and they are carried in the urine stream - They then stick to the antibodies in the window too, so it appears blue

3) If you are NOT pregnant, the antibodies attached to the blue beads are still carried past, but they don't stick, so it doesn't appear blue.

What are the main uses for monoclonal antibodies?

Pregnancy tests, Diagnosing and treating cancer, finding blood clots

Why do monoclonal antibodies stick only to that specific cell? How about cancer cells?

Cells have specific antigens on the cell surface that the monoclonal antibodies will stick to ONLY that molecule.

Cancer cells have have specific antigens on the cell membrane that aren't found on normal cells called 'tumour markers'. You can make monoclonal antibodies that bind to these

How can you use Monoclonal antibodies to diagnose cancer?

Monoclonal antibodies for cancer cells are labelled with a radioactive element. This is dripped into a patient, and wherever there is a tumour, they'll stick. A radioactive camera can then see this as a bright spot, which can be used to see if the cancer is spreading, what size it is etc...

How can you use Monoclonal antibodies to treat cancer?

A Cancer drug is attached to monoclonal antibodies for tumours. These then travel to the cancer cell and dispense the drug. This means that ONLY the cancer cells will be killed, whereas others aren't, unlike radio or chemotherapy.

How can you use Monoclonal antibodies to find blood clots?

When blood clots, proteins join together to form a 'mesh'.

Monoclonal antibodies for these proteins are labelled with a radioactive element. This is injected into a patient, and wherever there is a blood clot, they'll stick. A radioactive camera can then see this as a bright spot, which can be used to see where there are any blood clots

What is a good use for plants? (in this topic ovbiously...) Give examples.

Some plants produce their own chemicals to defend themselves, which can be used to treat human diseases too. E.g. Asprin is a pain killer and treats fever, that was developed from a chemical in willow bark

Why do pests reduce crop yields and why is this bad?

1) Pests can eat the fruit or crops, fruit flies eat fruit

2) Weeds growing near plants will compete for nutrients. With fewer nutreints, the plants will grow less, meaning lower crop yeids

3) If plants are attacked by a pathogen, they use up energy fighting it, which means they grow less. Heavy infestation can kill a whole crop

Pests cause costs to rise to cover the costs of pesticide etc...

What does photoperiodic mean, and what is photoperiodic?

It responds to day length (amount of light). Generally plants are.

Why do plants need to respond to light levels + Examples?

1) Some need to germinate when the days are very long, like arctic plants to grow

2) Some need growing day length to tell them that it's far enough from winter to grow, so they aren't frozen

3) Some (spinach) only flower when a day is a certain length to flower in midsummer, whilst some (primroses) only flower when the day is LESS than a specific length to flower in autumn or spring. Only at these times are the right pollinating insects around

What is the name for a daily cycle + examples?

Circadian Rhythms -

Sleep/Wake cycle - Sleep at the best times for the most rest. When it gets dark, Melatonin is released, making you feel tired.

Urine production - Your body relelases MORE ADH at night, so your sleep is not interrupted.

What are examples of plant circadian rhythms?

Stomata only open in the day (response to light levels) to allow for photosynthesis, but close at night to stop water loss

Flowers only open (response to light levels) when their pollinators are active: Tobacco plants only open at night because they are pollinated by moths