extra questions b11

Question 1

Which metabolic process produces water?

Answer 1

respiration of glucose

Question 2

Insulin cannot be taken as a tablet. This is because insulin is a type of protein.
What would happen to the insulin in the tablet if it reached the stomach?

Answer 2

would be digested / broken down by enzymes

Question 3

Explain why more water was lost by breathing during the race

Answer 3

• more energy needed
• more respiration
• increased breathing rate
• more oxygen needed

Question 4

Describe how the oral contraceptive pill stops a woman becoming pregnant.

Answer 4

inhibits FSH production
prevents egg maturation
prevents ovulation

Question 5

What is a hormone? (3 marks)

Answer 5

chemical messenger that targets specific organs, travels in blood, made by endocrine system

Question 6

Name the two hormones that control blood glucose concentration.

Answer 6

Glucagon and insulin

Question 7

Explain how negative feedback controls the blood glucose concentration
during the first one and a half hours after the meal.

Answer 7

• increase in blood glucose
• glucose detected by pancreas
• pancreas secretes insulin
• liver converts glucose to glycogen
• low blood glucose detected by pancreas
• pancreas releases glucagon
• liver converts glycogen to glucose (which enters blood)
• blood glucose rises

Question 8

Explain how blood glucose levels are controlled in the body of someone who
does not have diabetes.

Answer 8

if too high insulin released from pancreas
so glucose is moved into cells
allow glucose is stored
if too low, glucagon is released (from pancreas)
causes glycogen to be converted to glucose and released into the blood

Question 9

Hyperthyroidism is caused by an overactive thyroid gland.
Suggest what would happen in the body of a person with hyperthyroidism.

Answer 9

Too much thyroxine is released into the blood
which raises BMR
causing increase in formation of glycogen

Question 10

Explain why missing a dose of the mini-pill would reduce the success rate of
the mini-pill.

Answer 10

drop in progesterone levels, FSH is not inhibited anymore LH is not inhibited anymore egg is matured and released

Question 11

Explain why a transplanted organ may be rejected.

Answer 11

white blood cells produces antibodies
(which) attack the antigens on the transplanted organ / pancreas

Question 12

The table shows that both protein and glucose are found in the blood
plasma but not in the urine.
Use your knowledge of kidney functioning to explain why.

Answer 12

protein (too) big cannot pass through filter
(glucose) small can pass through filter, all reabsorbed

Question 13

Why should sports drinks contain ions?

Answer 13

replace ions lost

Question 14

Protein is not found in the urine of a healthy person. Explain why

Answer 14

(protein) molecule is large
cannot pass through filter

Question 15

Substance B is not found in the urine of a healthy person.
Suggest an explanation for this. diameter of 1

Answer 15

B is reabsorbed completely

Question 16

The number of cases of Type 2 diabetes in the UK is increasing rapidly.
(a) Describe how insulin and glucagon help control the blood sugar concentration in a healthy person.

Answer 16

insulin is produced by pancreas
* if blood glucose levels are too high, insulin is produced
* allowing glucose to move from the blood into the cells
* glucose is converted to glycogen
* if blood glucose levels fall, glucagon is produced
* glycogen is converted to glucose
* causing glucose to be released into the blood

Question 17

The concentration of glucose in the blood of the two vessels is different.
Explain why.

Answer 17

(concentration high) in the hepatic portal vein is blood with glucose absorbed from
the intestine
concentration is lower in the hepatic vein because insulin
(has caused) glucose to be converted into glycogen

Question 18

The person does not eat any more food during the next 6 hours after the meal.
However, 6 hours after the meal, the concentration of glucose in the blood in
the hepatic vein is higher than the concentration of glucose in the blood in the
hepatic portal vein.
Explain why.

Answer 18

because glucagon (made in the pancreas) causes glycogen to be converted into glucose
glucose released into blood

Question 19

Suggest two ways to improve the students method for measuring human reaction time

Answer 19

• repeat and calculate mean
• more precise scale

Question 20

Give two ways the endocrine system is different from the nervous system

Answer 20

• hormones via blood
• chemical transmission
• slower
• longer lasting

Question 21

Explain the use of hormones in contraception and treatment of infertility

Answer 21

Contraception
- uses oestrogen and progesterone
inhibits FSH
- prevents follicle maturation, no egg to fertilise
inhibits LH
- prevents ovulation, no egg to fertilise
- methods include contraceptive pill, injection, IUD, implant etc
Fertility
FSH
- stimulates maturation of several eggs
- increases the number of eggs matured
LH
- stimulates ovulation
- allows egg to be collected from ovary
- IVF and insertion of embryos into uterus
- progesterone to maintain uterus inking an d increase chance of implantation

Question 22

What is homeostasis

Answer 22

Regulation of internal conductions for optimum conditions for cells/enzyme activity

Question 23

Explain how the concentration of substance Q is controlled by negative feedback

Answer 23

• if concentration of Q becomes high hormone a is released
• if concentration of Q becomes low b is released
• hormone a/b brings concentration of q back to normal

Question 24

Explain how thyroxine causes an increase in body temperature

Answer 24

• increases metabolic rate
• respiration increases temperature

Question 25

People with the muscle disease are not able to store glycogen in their muscles. The results shown in the graph for the person with the muscle disease are different from the results for the healthy person. Suggest an explanation for the difference in the results.

Answer 25

cannot store glucose need to receive glucose / sugar for energy

Question 26

In the first stage of in-vitro fertilisation (IVF), eggs from the mother are fertilised with sperm from the father. Describe the next stages of IVF.

Answer 26

embryo inserted into uterus

Question 27

Describe the process of IVF.

Answer 27

egg(s) collected from ovary * (eggs) mixed with sperm * embryo formed * (embryos) inserted into womb / uterus

Question 28

A person with type 2 diabetes has higher blood insulin concentration than a non-diabetic person. Explain why.

Answer 28

- cells absorb less glucose - so glucose concentration remains high - high blood glucose causes pancreas to release more insulin

Question 29

Suggest why a blood test is more reliable than a urine test

Answer 29

Blood gives current result, urine levels might be several hours old

Question 30

Suggest why patients are not allowed to eat 8 hours before the blood test

Answer 30

So results aren’t affected by glucose from food

Question 31

Explain why missing a dose of the mini pill would reduce the success rate of the mini pill (progesterone only)

Answer 31

- causes drop in progesterone levels - FSH and LH not inhibited anymore - egg is matured and released

Question 32

Explain why a transplanted organ may be rejected

Answer 32

Immune system produces antibodies which attack the antigens on the transplanted organ

Question 33

What happens to the woman with the artificial pancreas to bring blood sugar back to normal

Answer 33

- rise detected by sensor - information used to calculate how much insulin she is going to need - pump delivers insulin into the blood - causing glucose to move into cells

Question 34

The student stated: ‘metoformin works better when used with other drugs’ Evaluate the students statement

Answer 34

Pros: - met + a gives larger % reduction than met alone - met + b gives larger % reduction than met alone - med + A SD does not overlap with met SD, so difference is significant Cons: - met +B SD overlaps with met SD - so difference is not significant - difference could be due to chance - number of people used not very large - may not be repeatable - concentration of drugs may differ