Name:
Instructions To Candidates
Write your name in the spaces provided.
Answer all questions
Information for candidates
The numbers of marks is given in brackets [ ] at the end of each question or part question.
The total marks for this paper is 80.
This paper consist of 11 printed pages and no blanks
1. (a) Fig. 1.1 is a photomicrograph showing a surface view of many villi in the small intestine.
(i) State the function of villi [2]
(ii) Describe the structure of the villus [3]
(b) Blood transports nutrients.
(i) State the component of the blood that transports nutrients [1]
(ii) The nutrients in the blood can be used to become part of cells.
State the name of this process [1]
(iii) Amino acids are used to make proteins.
State two examples of proteins that are found in the blood [2].
1.
2.
(c) Explain the effect of cholera bacteria on the digestive system [4]
[Total 12 marks]
2. The Fig below shows a photomicrograph of human blood.
(a) Describe the differences in appearance and the functions of the three cells labelled in
The above diagram [6]
(b) The figure below shows some of the stages of blood clotting.
(i) Complete the figure by filling in the 2 empty boxes. [1]
(ii) State two roles of blood clotting [2]
1.
2.
(c) Haemophilia is a sex-linked blood disorder. The blood of people with haemophilia takes
longer to clot. The figure below is a pedigree diagram showing the inheritance of haemophilia.
• The allele for normal clotting time is represented by XH.
• The allele for haemophilia is represented by Xh .
(i) State the genotypes of the people identified as P, Q and R in the figure [3]
P
Q
R
(ii) The couple S and T are expecting another child.
State the probability that the child will have haemophilia. [1]
(ii) Describe what is meant by the term sex-linked characteristic.[2]
[Total: 15]
3. (a) Organisms from the genus Chlorella are protoctists.
State the additional information required to name Chlorella according to the binomial system. [1]
(b) The figure below shows the structure of an organism from the genus Chlorella.
(i) Identify two cell structures in Fig above that indicate that Chlorella is not a prokaryote.[2]
1.
2.
(ii) Identify two cell structures in Fig. above that are found in both fungi and protoctists.[2]
(iii) State the names of two other kingdoms, apart from fungus, prokaryote and protoctist. [2]
(c) Chlorella is sold as a nutritional supplement.
Spirulina is another nutritional supplement.
Table shows some nutritional information for Chlorella and Spirulina supplements and the
recommended daily intake for some nutrients.
(i) One tablet contains 5 g of Chlorella supplement.
Using the information in Table 1.1, calculate the number of tablets of Chlorella supplement
a person needs to take to provide the recommended daily intake of iron.
Give your answer to one decimal place.
Show your working…. [3]
(ii) Explain the advantages of taking Chlorella as a dietary supplement rather than Spirulina.
Use the data in Table 1.1 to justify your answer [4].
(iv) State the name of one food that is a principal dietary source of vitamin C. [1]
(d) Chlorella is also a good source of protein.
(i) State the importance of proteins in active transport [2].
(iii) State the name of the smaller molecules that proteins are made from.
[Total: 17] marks
4. (a) Fig. below is a diagram of the gas exchange system in humans.
(i) State the names of the parts labelled X, Y and Z [3].
X
Y
Z
(ii) The wall of the trachea contains rings of tissue.
State the name of this tissue and describe its functions.
Name [1]
functions [2]
(iii) State the names of two types of cells responsible for protecting the breathing system
from particles [2]
(b) A scientist estimated the pressure and volume in the thorax during one breath.
Fig. below shows a graph of the results.
Describe and explain the changes in the thorax that occur during section A only in Fig. Above [6].
(c) Complete the sentences to describe the effect of carbon dioxide concentration on breathing.
During physical activity, the carbon dioxide concentration of the blood
........................................… This is detected by the .........................................…………………
This results in an increased rate and greater ........................................... of breathing. [3]
16 marks
5. (a) Fig. 4.1 shows a diagram of two flowers from different plants of the same species.
(i) Describe what is meant by the term species [2].
(ii) Complete the diagram in Fig. 4.1 to show self‑pollination and cross‑pollination by:
• drawing one arrow to show the pathway of pollen during self‑pollination and labelling this arrow
self‑pollination
• drawing one arrow to show the pathway of pollen during cross‑pollination and labelling this arrow
cross‑pollination
• labelling the names of the structures involved in pollination.
(ii) State the function of the parts labelled X and Y in Fig. 4.1 [2]
(b) Explain why self‑pollination that results in production of offspring is a form of sexual
reproduction and not asexual reproduction. [3]
(c) State the type of environmental conditions that hydrophytes are adapted to live in.[1]
[Total: 12]