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Question 1
The endocrine system coordinates many internal functions of the body. |
a) | Give three ways in which the endocrine system differs from the nervous system.
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b) | The response of the skin to cold weather is an involuntary action. How is an involuntary action different from a voluntary action?
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c) | Give the name of the process by which the internal conditions of the body are maintained.
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Question 2
A man goes for a run. Exercising causes the man's body temperature to rise. |
a) | When the man’s core body temperature rises, his rate of sweating increases. Explain why.
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b) | The man arrives home after his run. The man’s skin looks very red. Describe what happened to the blood circulation in his skin to cause this change in colour.
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c) | The man has a very cold shower. This makes the man shiver. What causes shivering?
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d) | Shivering increases the man's body temperature. Explain how.
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Question 3
A diabetic woman needs to calculate the number of grams of carbohydrate in her meals. She then uses the mass of carbohydrate to calculate the number of units of insulin she will need to inject to lower her blood glucose concentration. She takes no other medications. |
a) | Does the woman suffer from type 1 or type 2 diabetes? Explain your answer.
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b) | The woman eats a jam doughnut and drinks a hot chocolate before going to bed. The doughnut contains 38 g of carbohydrate. The hot chocolate contains 12 g of carbohydrate. The woman needs to inject 1 unit of insulin for every 10 grams of carbohydrate she consumes. |
How many units of insulin will she need to inject to control a rise in her blood glucose levels?
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c) | Apart from injecting insulin, give one other way the woman could help to control the concentration of glucose in her blood.
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d) | The body cells of a person with untreated diabetes lose more water than the cells of a person without diabetes. Explain how diabetes can cause the cells to lose more water.
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Question 4
A scientist studied two populations in very different environments. One of the populations lives in a hot desert. The other population lives in a rainforest. The scientist recorded the air temperature, mean humidity levels and mean wind speed, in the desert and in the rainforest. The scientist also recorded the core body temperature of members of both populations. The data was recorded in the table below. |
a) | Why is it important to maintain a constant body temperature? A to provide kinetic energy for our bodies to move B to maintain the optimum temperature for enzymes to work C to prevent feeling cold D to provide the ideal temperature for mitosis
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b) | Use information from the table and your prior knowledge to explain the difference in the mean core body temperature of the members of the two tribes.
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c) | What happens to blood vessels if a persons core body temperature is too high? A the capillaries constrict B the capillaries dilate C the capillaries move closer to the surface of the skin D the blood vessels supplying the capillaries dilate
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Question 5
Homeostasis keeps conditions in the body relatively constant. Body temperature and the amount of water in the body are both controlled by homeostasis. Kidney function is controlled by a gland in the brain. |
a) | Describe how the water content of the blood is controlled.
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Question 6
Homeostasis keeps conditions in the body relatively constant. Body temperature and the amount of water in the body are both controlled by homeostasis. The human body maintains a constant core body temperature of around 37°C. |
a) | Describe what happens in the body to keep the body temperature constant.
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Question 7
The kidneys maintain a near constant amount of water in the body. The table shows the volume of water that the kidneys filter from the blood and the volume of urine produced in one day. |
a) | Calculate the volume of water reabsorbed into the blood that day.
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b) | A man is exercising on a very hot day with no access to drinking water. Explain how his body reduces water loss.
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c) | Which of the substances are found in the urine of a healthy person? Add ticks to the correct boxes.
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d) | Explain, for each of the four substances in c), why they are found in the urine of a healthy person or not.
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Question 8
Urine is produced by the kidneys before being stored in the bladder. |
a) | Describe how urine is produced by the kidneys.
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Question 9
Some people suffer from diabetes. People with type 1 diabetes do not produce enough insulin to maintain an appropriate level of blood glucose. |
a) | Which organ in the body monitors blood glucose concentration? A brain B liver C pancreas
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b) | Insulin causes its target organs to take in glucose from the blood. Which of the following is a target organ for insulin? A heart B bladder C liver
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c) | Explain how blood glucose levels are controlled in the body of a person who does not suffer from diabetes.
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d) | The control of blood sugar is an example of a negative feedback mechanism. State what is meant by negative feedback and explain how negative feedback works.
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e) | Insulin is a protein. Insulin must be injected as it cannot be taken as a tablet. Suggest what would happen to an insulin tablet if it reached the stomach.
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f) | Compare the causes of type 1 and type 2 diabetes, and explain how each type of diabetes can be treated.
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Question 10
The diagram below shows a cross section of human skin. |
a) | Name structures A, B and C.
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b) | Describe the appearance of human skin when the temperature drops.
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c) | Use information from the diagram and your own knowledge to explain the change in appearance of human skin following exposure to a cold environment.
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Question 11
Sports drinks are beverages specially formulated to help people rehydrate during or after exercise. |
a) | Why should sports drinks contain ions?
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b) | Marathon runners often drink sports drinks during a race. How do sports drinks help an athlete release energy whilst running a marathon?
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The table shows the concentrations of glucose and ions in three different sports drinks, X, Y and Z. |
c) | The body will replace water faster if the ratio of glucose to ions in the sports drink is close to 1:1. Which of the sports drinks will replace water more efficiently? A drink X B drink Y C drink Z
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d) | An athlete with diabetes was warned not to drink too much sports drink. He was told to avoid drinking sports drink Z. Explain why a diabetic athlete should be careful with the intake of sports drinks.
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