Steps in drug trialling: Firstly, the drug is discovered (not sure if optional). Then lab research is done on it. Next, it is tested on animals, then cells/ tissues, then on human volunteers. Penultimately the drug is evaluated by researchers before it is finally sold to doctors.

Q: How does vaccine make someone immune to a disease (3 marks)

Reply 5

dhruvap

The drugs are first tested in labs where they use cells to see how strong the drug is. The drug is then tested on live animals to find its toxicity and effectiveness, this test also gives an indication on the optimum dosage required. Clinical trails involve testing the drug on healthy patients first, they are given the drug to see possible side effects and also to find out how safe they are on humans. The number of Volunteers is increased to see if there are possible problems with the drug on patients with different body factors. They are finally tested on people with the illness where they try and find the optimum dosage.

Additional notes: Double-blind trails are when the doctor and the patient don't know who is taking placebo and who is taking the actual drug.

Explain how MRSA has become resistant to some types of antibiotics (4/5 marker ?)

Reply 6

tmansfield039

Rate at which chemical reactions take place in body

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Reply 7

dhruvap

Original post by IAmAnTroll

Vaccines are dead/inactive versions of the pathogen, they activate the white blood cells to detect them and produce antibodies that kill off the pathogen. The antibodies will replicate themselves if they see the pathogen again as white blood cells have added the pathogen in their directory.

Reply 8

Hasib_332

MRSA has become resistant to some types of antibiotic due to natural selection. There is variation in the bacterium population, a mutation may lead to resistance to antibiotics. Those with resistance are better adapted to their environment and they survive, and they pass on their beneficial gene, whereas those without the beneficial gene die. Over time an entire population of antibiotic resistant bacteria will be found.

Describe how a vaccination prevents disease in the future?

Reply 9

IAmAnTroll

Original post by dhruvap

Mutations of pathogens produce new strains. Some strains are resistant to the antiobiotic. These survive when the antibiotic is applied. They reproduce and a whole population of antiobiotic-resistant bacteria are produced. Aka natural selection

Q: How are polar bears adapted to survive in extremely cold conditions?

Reply 10

dhruvap

Original post by MarcusThePotato

How are polar bears adapted to their environment?

Polar bears have small ears to reduce eat loss due to a lower surface area. They also have thick fur to stay insulated, also reduces heat loss and therefore keeps body warm. They have padded paws that enable them to walk on snow without losing heat. They have white fur to camouflage with surrounding snow so that they can track and kill prey easily.

Reply 11

IsaacVB

What is meant by a balanced diet? 2 marks

Reply 12

dhruvap

Explain how lichens can be used to detect environmental changes.

Reply 13

IAmAnTroll

Original post by Hasib_332

A vaccination contains a dead or inactive form of a pathogen
the pathogen is inserted into the blood stream
the white blood cells react by producing antibodies which target these pathogens and kill them
when the pathogen gets into the body again the white blood cells can respond quickly by producing antibodies to kill the pathogen

Reply 14

tmansfield039

Have a thick fur and fat under skin to keep warm, have small surface area to volume ratio to conserve energy. Have small Ears to reduce heat loss.

Q. What does FSH do and where is it produced?

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Reply 15

IsaacVB

Name hormones of the menstrual cycle and what they do (4 marks)

Reply 16

IsaacVB

Original post by dhruvap

Explain how lichens can be used to detect environmental changes.

They can't grow in areas of high amounts of methane and sulphur dioxide

Reply 17

LaurenHannahL

Original post by MarcusThePotato

How are polar bears adapted to their environment?

Polar bears have a thick layer of blubber which act as an insulator
The have a large surface are to volume ratio which helps them store heat
They have small ears which prevent heat loss
They are white which helps them camouflage into the snow to hide them from predators
They have a thick coat which acts as an insulator

Question, What are the different hormones in the menstrual cycle and what do they do?

Reply 18

dhruvap

Original post by IsaacVB

What is meant by a balanced diet? 2 marks

A balanced diet is a diet containing food from all the different categories of food, for example Proteins, carbohydrates and Fats in the optimum quantity.

Reply 19

IAmAnTroll

Original post by tmansfield039

FSH is produced in the pituitary gland and matures the egg and stimulates the production of LH

Q: Explain how phototropism and geotropism work in plants (6 marks)