7.2 Homeostasis

Insulin is produced by an endocrine gland and is transported in the blood.

Which row shows the endocrine gland and the target organs for insulin?

(1)

Which part of the blood transports insulin to its target organs?

(1)

Figure 1 shows the blood glucose and blood insulin concentration for a healthy person during one day.

Figure 1

The blood glucose concentration increases after a meal.

Explain why the blood glucose concentration then decreases.

State one cause of type 1 diabetes.

Explain how controlling the diet can be used to treat type 2 diabetes.

A scientist is planning to test a new treatment for type 2 diabetes.

She selects 300 volunteers who have type 2 diabetes.

State two other factors that the scientist should consider when selecting the 300 volunteers.

Explain why it is important to control the internal temperature of the human body.

A person had symptoms including difficulty passing urine, aching in the lower abdomen, constant thirst and fainting.

A sample of their urine was tested.

The results are shown in Figure 1.

test	result	acceptable range
Glucose	200 mg per dl	0 to 130 mg per dl
Albumin (protein)	16 mg per dl	0 to 3 mg per dl
pH	3	5 to 7
Leukocytes (white blood cells)	40	2 to 5

Figure 1

A doctor analysed the results and asked the person to have further tests for type 2 diabetes.

Give a reason why the doctor came to this conclusion.

(1)

(ii)

Explain why the doctor also concluded that the person had a kidney infection.

(2)

A hospital patient was tested for diabetes.

A nurse recorded his mass and height.

Figure 1 shows these measurements.

mass in kg	height in metres
124	1.8

Figure 1

Calculate the BMI of this patient using the information in Figure 1.

Blood samples were taken from this patient every four hours.

The glucose concentrations were recorded in Figure 2.

Figure 2

Describe the trends shown in this data.

(3)

(ii)

This patient was diagnosed as being type 2 diabetic.

Explain why the blood glucose concentration of this patient remained high from 4 hours to 8 hours.

(3)

(iii)

This patient did some exercise during these 24 hours.

Explain how the data in Figure 2 shows that this exercise occurred after 8 hours but before 12 hours.

(3)

Endocrine glands make hormones.

Which endocrine gland is situated in the head and is attached to the brain?

Diabetics cannot effectively control the concentration of glucose in their blood.

Person A has type 1 diabetes.

Person B has type 2 diabetes.

Draw one straight line from each person to the cause of their type of diabetes.

A scientist investigated how the waist to hip ratio affected the probability of developing type 2 diabetes.

The scientist chose 100 females in each of five waist to hip ratio groups and recorded if they developed type 2 diabetes.

Figure 1 shows the results.

Figure 1

Describe the trend shown in Figure 1.

Use data from Figure 1 in your answer.

(2)

(ii)

A female has a waist measurement of 78.3 cm and a hip measurement of 90.0 cm.

Calculate the waist to hip ratio for this female and use Figure 7 to estimate the probability that she will develop type 2 diabetes.

(2)

The scientist also measured the BMI of the females.

BMI and waist to hip ratio are two factors that affect the probability of females developing type 2 diabetes.

State two other factors about the females in the study that would affect the probability of them developing type 2 diabetes.

(2)

State why an athlete may have a high BMI but still have a low probability of developing type 2 diabetes.

(1)

Urease is an enzyme that breaks down urea into smaller molecules.

Explain why urease will not break down starch into smaller molecules.