CAIE IGCSE Biology 17 Inheritance
Review DNA, genes, protein synthesis, mitosis, meiosis and monohybrid inheritance through diagrams, crosses and data.
- Syllabus
- 2026–2028
- Course
- Biology 0610
Covered syllabus points
17. Inheritance question 1
Question (a)
(a)
A scientist investigated sexual reproduction in flowering plants.
Fig. 2.1 shows the procedure for crossing two plants of the same species.
The scientist collected the seeds and germinated them. The leaves and flowers of the offspring plants showed phenotypic variation as they were not all identical to the parent plants.
The scientist then investigated the chromosomes of all the offspring plants and found that they had exactly the same number of chromosomes as the parent plants.
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Question (i)
(i)
Define the term chromosome.
[ 2 ]
Question (b)
(b)
The plant Camellia japonica has flowers that can be white, red or a mixture of these two colours. When red-flowered plants are crossed with white-flowered plants, all the offspring plants have flowers with petals that are a mixture of red and white, as shown in Fig. 2.2.
Fig. 2.2
- The gene for petal colour in C. japonica is given the symbol P.
- The allele for white petals is given the symbol .
- The allele for red petals is given the symbol .
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Question (i)
(i)
Table 2.1 shows the phenotypes of three different pairs of parent plants.
Complete Table 2.1 by giving all the possible genotypes of the offspring plants that could be produced by these parent plants.
.
Table 2.1
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Question (ii)
(ii)
State the type of inheritance that is shown by petal colour in C. japonica.
[ 1 ]
17. Inheritance question 2
Penicillin is an antibiotic produced by the fungus Penicillium chrysogenum.
Fig. 5.1 shows the process used to produce penicillin.
Fig. 5.2 shows the mass of fungus and the yield of penicillin during the fermentation process.
Fig. 5.2
As the fungus grows in the fermenter, the nuclei in the fungal hyphae divide.
State the type of nuclear division that occurs during the growth of the fungus in the fermenter.
17. Inheritance question 3
Fig. 4.1 is a photograph of a bee on a flower. One of the bee's legs is covered with pollen.
Fig. 4.1
Sexual reproduction also occurs in humans.
Human male gametes are haploid.
State the name of the process that produces haploid male gametes.
17. Inheritance question 4
Colour blindness is a characteristic that is inherited. Colour blindness is more common in males than in females.
Fig. 6.1 is a pedigree diagram showing the inheritance of colour blindness in a family.
Fig. 6.1
Question (a)
(a)
Define the term inheritance.
[ 1 ]
Question (b)
(b)
Using the symbols B and b, state the genotypes of individual 5 and individual 8 in the pedigree diagram.
5
8
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Question (c)
(c)
Individual 3 is a carrier of colour blindness because she has one copy of the allele for colour blindness but has normal colour vision.
Describe the evidence from Fig. 6.1 that shows that individual 3 is a carrier.
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