QUESTION 24 (3 marks)
a) Describe what is meant by the genotype of an organism.
[1 mark]
b) Inherited mutations can affect the genotype of offspring. Describe how this occurs.
[2 marks]
QCAA guide · typeset solution
QCAA sample response and mark allocation
24 | a) | Genotype refers to the combination of alleles that an organism has. | • states combination of alleles [1 mark] | Accept: the set of genes in its DNA responsible for a particular trait/phenotype your complete heritable genetic identity the genetic constitution of an organism. |
24 | b) | The parent of the offspring would have a mutation that is inheritable (in sex organs) and creates a new allele (variation of a gene). The genotype of an offspring may then be affected as it would contain new alleles if the mutated gene from an egg or sperm is present in the zygote at fertilisation. This will then affect the genotype of the offspring. | • states a description of the mutation being a new allele of a gene [1 mark] • states genotype contains new alleles if/when inherited [1 mark] |
QCAA sample response and marking criteria reproduced from the official guide.
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