Edexcel GCSE Biology: Combined Science

Topic Questions

8.1 Transport in Animals

1a
Sme Calculator
1 mark

Organisms must transport substances to and from the external environment.

Identify one substance which cells must transport across the cell membrane to support cell functions.

1b
Sme Calculator
2 marks

The diagram shows particles of two gases.

diffusion-1
(i)

Complete the diagram by drawing the arrangement of the gas particles after 1 hour.

(1)

(ii)

Name the process shown in part (i).

(1)

1c
Sme Calculator
3 marks

Describe an example of where movement of gases as shown in part (b) is important in multicellular organisms.

Did this page help you?

2a
Sme Calculator
2 marks

Identify one example of an exchange surface found in the human body and name one substance which moves across this exchange surface.

2b2 marks

Figure 1 shows a single celled organism called an amoeba. An amoeba does not possess any transport systems such as those seen in the human body.

amoeba-sq-1

Figure 1

Explain why this amoeba does not require a specialist transport system to obtain the substances that it requires

Did this page help you?

3a1 mark

Multicellular organisms, such as humans, use transport systems to deliver substances such as oxygen and glucose around the body.

Name the transport system which moves oxygen and glucose around the body.

3b
Sme Calculator
2 marks

Fill in the table to correctly identify the transport tissues found in plant transport systems.

Transport Tissue Role of transport tissue
  Moves water and minerals from roots and shoots
  Moves sugars and amino acids around the plant
3c
Sme Calculator
3 marks

Identify the three transport processes used for exchange of substances across the cell membrane.

3d
Sme Calculator
3 marks

Separate: Biology Only

Figure 1 shows a structure found within the human gas exchange system.


gas-exchangegas-exchange

Figure 1

(i)

Identify the structure shown in Figure 1.

(1)

(ii)

The structure in Figure 1 has a good blood supply. 

Explain how this helps to ensure efficient gas exchange.

(2)

Did this page help you?

4
Sme Calculator
6 marks

Compare and contrast the surface area to volume ratios in single-celled organisms and multicellular organisms.  

Did this page help you?

5a
Sme Calculator
2 marks

A student was studying the surface area to volume ratio of three different organisms A, B and C which can be seen in Table 1 below. 

Table 1

Organism A B C
Surface area/ mm2 0.36 4 14
Volume/ mm3 0.03 0.5 7
Surface area to volume ratio 12:1 8:1 2:1

Using Table 1 above and your own knowledge, suggest which organism would benefit from a transport system. 

Justify your answer.

5b
Sme Calculator
2 marks

The student determined the rate of oxygen uptake for the three organisms as:

5.0 cm3 g -1 h-1
0.3 cm3 g -1 h-1
12.0 cm3 g -1 h-1

Suggest which of the three oxygen uptakes would be for organism C and a reason why.

5c
Sme Calculator
3 marks

Explain the significance of the rate of oxygen diffusion in the respiratory system of an organism.

Did this page help you?

1a4 marks

Unicellular organisms such as bacteria, can obtain oxygen from their surrounding environment through simple diffusion across the cell membrane.

In larger multicellular organisms, the distance from their surface to their centre is relatively long. Consequently, atmospheric oxygen cannot diffuse into the cells in the centre of the organism as they are too far away.

(i)
Describe how multicellular animals have adapted to facilitate transport of oxygen to cells.

(2)
(ii)
Describe two ways in which the human small intestine is adapted for absorbing dissolved food molecules.
(2)
1b
Sme Calculator
2 marks

Calculate the surface area : volume ratio of a cube that has a side length of 3cm.

1c3 marks

Describe the features that make a gas exchange surface efficient.

Did this page help you?

2
Sme Calculator
6 marks

Figure 1 shows three cubes with sides of length 1 cm, 2 cm and 3 cm, the cubes represent imaginary cells.

bn4bZv0__1

Figure 1

During an exam, a student looked at Figure 1 and wrote the following statement:

"as cells get bigger their surface area to volume ratio gets bigger"

(i)
Explain why the students statement is incorrect. Use the information in Figure 1 and show calculations in your answer.
(3)
(ii)
Complete the missing information in Figure 2 
(3)
Cube size (cm) Surface area (cm2) Volume (cm3) Surface area : Volume ratio
1      
2      
3      

Figure 2

Did this page help you?