3.3 Maintaining Internal Environments

Higher Tier only

The diagram shows a kidney tubule (nephron).

The diagram shows the composition of glomerular filtrate and urine.



What evidence is there to suggest that selective reabsorption occurs in the kidney tubule?

Use evidence from the diagram to support your answer.

Higher Tier only

Sports drinks are usually one of three types. Look at the table of information on these types of sports drink.

An athlete is going to run a 10000 metre race. About an hour before the race the athlete drinks a hypertonic sports drink.

The athlete completes the 10000 metre race. After the race the athlete drinks an isotonic sports drink.

Explain how the race causes changes in water, salt and sugar levels in the athlete’s body and explain the athlete’s choice and timing of drinks.

This question is about control and coordination.

The diagrams show a section through the skin in two different conditions.


Which diagram shows the skin in a hot, humid environment?

Explain your answer.

Look at the diagram.

It shows a vertical section through a kidney.

The kidney is important for water balance.

The table shows the measurements of water balance for two patients in hospital.

Patient A .......................................
Patient B .......................................
[1]

[2]

Look at the diagram. It shows a kidney tubule (nephron).

The diagram shows the composition of glomerular filtrate and urine.



What conclusions can be made about what happens between part Z and the collecting duct in the kidney tubule?

Use evidence from the diagram to support your answer.

Fig. 17.1 shows the mass of urea in the urine plotted against the BMI (Body Mass Index) for nine boys. BMI is a value often used to see if a person is a healthy mass for their height.

Fig. 17.1

[1]

Concentration = ....................g/cm³ [2]

Fig. 17.2 shows the mass of urea in the urine against the BMI for nine different boys.

[2]

The kidney filters the blood. The fluid produced by filtering the blood passes through kidney tubules.

Each kidney tubule contains a number of different parts.

Put a number (1 to 5) in the boxes to show the order of the parts that the liquid passes through.

The first one has been done for you.

Fig. 20.1 shows a section through the skin on the back of the hand.

Fig. 20.1

The skin on some areas of the body contains hairs. Modern hair shampoos contain cleaning agents. One cleaning agent is made from fatty acids.

Explain how a polymer found in plants and animals can be treated to obtain these fatty acids.

[2]

Look at Fig. 20.2 which shows two people riding on boards.

Person A is riding a board on sand in a hot desert. Person B is riding a board on snow.

[6]

Red blood cells burst when they are placed in a solution with a much higher water potential than the red blood cells. This is called lysis. 

Explain why lysis happens.

Higher Tier only

ADH is a protein hormone made up of amino acids.

Alcohol inhibits ADH production.

Person A and B both drank one small 100ml drink.
Only one of the drinks was high in alcohol.

Look at the diagram of a kidney tubule in person A and B after the drink.


Explain how you can tell from the diagram that person A’s drink contained alcohol.

[2]

[2]