Biology 0610/42 October/November 2024: question paper and mark scheme

Question

(a) Organisms from the genus Chlorella are protoctists. State the additional information required to name Chlorella according to the binomial system. …… [1] (b) Fig. 1.1 shows the structure of an organism from the genus Chlorella. cytoplasm nucleus cell wall cell membrane chloroplast Fig. 1.1 (i) Identify two cell structures in Fig. 1.1 that indicate that Chlorella is not a prokaryote. 1 …… 2 …… [2] (ii) Identify two cell structures in Fig. 1.1 that are found in both fungi and protoctists. 1 …… 2 …… [2] (iii) State the names of two other kingdoms, apart from fungus, prokaryote and protoctist. …… and …… [1] (c) Chlorella is sold as a nutritional supplement. Spirulina is another nutritional supplement. Table 1.1 shows some nutritional information for Chlorella and Spirulina supplements and the recommended daily intake for some nutrients. Table 1.1 mass of nutrient / mg per 100 g of supplement average recommended nutrient daily intake in adults Chlorella Spirulina / mg per day supplement supplement vitamin C 0.74 0.00 80.00 calcium 120.00 5.10 1000.00 iron 37.00 75.50 12.00 (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. Space for working. …… tablets [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] (iii) 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] (ii) State the name of the smaller molecules that proteins are made from. …… [1] [Total: 17]

Question

(a) Fig. 2.1 is a diagram of the gas exchange system in humans. trachea X Y Z Fig. 2.1 (i) State the names of the parts labelled X, Y and Z in Fig. 2.1. X …… Y …… Z …… [3] (ii) The wall of the trachea contains rings of tissue. State the name of this tissue and describe its function. name …… function …… [2] (iii) State the names of two types of cells responsible for protecting the breathing system from particles. 1 …… 2 …… [2] (b) A scientist estimated the pressure and volume in the thorax during one breath. Fig. 2.2 shows a graph of the results. one breath pressure in the thorax A B volume of air in the thorax time Fig. 2.2 Describe and explain the changes in the thorax that occur during section A only in Fig. 2.2. …… [5] (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] [Total: 15]

Question

(a) Fig. 3.1 shows a kidney nephron and its associated blood vessels. glomerulus B A C key direction of flow of fluid A Fig. 3.1 The compositions of fluids A, B and C were analysed. Table 3.1 shows the results for five components of the fluids. Table 3.1 percentage percentage percentage component concentration in concentration in concentration in fluid A fluid B fluid C water 90.00 90.00 94.00 glucose 0.10 0.10 0.00 protein 8.00 0.00 0.00 urea 0.03 0.03 2.00 ions 0.72 0.72 1.50 (i) State the names of fluid A and fluid C in Fig. 3.1. A …… C …… [2] (ii) Using the information in Fig. 3.1 and Table 3.1, describe and explain the differences in the compositions of fluids A, B and C. …… [5] (b) Outline how blood glucose concentration is controlled. …… [6] (c) A gene mutation may be involved in the development of type 1 diabetes. (i) Describe what is meant by a gene mutation. …… [2] (ii) Outline the treatment of type 1 diabetes. …… [3] [Total: 18]

Question

(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. X Y Fig. 4.1 [3] (iii) State the function of the parts labelled X and Y in Fig. 4.1. X …… Y …… [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: 11]

Question

Fig. 5.1 is a pedigree diagram showing the inheritance of blood group in one family. B A 1 2 B AB A O 3 4 5 6 key female O O O male 7 8 9 Fig. 5.1 (a) State the number of people in Fig. 5.1 with: XY chromosomes …… only one IA allele. …… [2] (b) Explain how Fig. 5.1 shows that blood group is an example of discontinuous variation. …… [2] (c) State one example of discontinuous variation in plants. …… [1] (d) Explain why the inheritance of blood group is an example of codominance. …… [2] (e) A person with the genotype IAIo has a child with a person with the genotype IBIo. Complete the genetic diagram to determine the probability of the offspring having the blood group AB. parent 1 parent 2 parental blood group A + blood group B phenotypes parental Ao + Bo genotypes gametes + offspring genotypes offspring phenotypes probability of the offspring having the blood group AB …… [4] [Total: 11]

Question

(a) The flow chart in Fig. 6.1 shows one pathway of nitrogen as it travels through the nitrogen cycle. Complete the flow chart in Fig. 6.1. nitrogen fixation by nitrogen-fixing bacteria uptake of …… nitrogen in the in the soil and ions and synthesis of atmosphere proteins by plants deamination in animals occurs to form decomposition of animal plants eaten by and plant matter to form herbivores …… ammonium ions in the liver the process of nitrification occurs to convert ammonium ions to occurs, returning nitrogen …… ions to the atmosphere Fig. 6.1 [5] (b) State the names of two processes that occur in both the carbon and nitrogen cycles. 1 …… 2 …… [2] (c) State the principal source of energy input to biological systems. …… [1] [Total: 8]