Biology B1.2 A - Explaining inheritance

Question	Answer
How is genetic information passed on?	By gametes.
What are gametes?	Sex cells: Egg from the mother, Sperm from the father.
What are gametes made from?	Body cells.
How many chromosomes do gametes have?	They have half the number as body cells - 23
Why do gametes have less chromosomes?	So when they meet, the resulting cell has the correct number of chromosomes.
What is point mutation?	The difference between 2 variants.
What is a dominant variant?	One dominant variant is needed in a pair of alleles to have its feature.
What is a recessive variant?	2 recessive variants are needed in a pair of alleged to have its feature.
What does homozygous mean?	When a person has 2 alleles that are the same.
What does heterozygous mean?	A person has 2 different alleles.
If a parent's genotype is EE, what percentage of there gametes will have the E variant?	100%
If a parent has a genotype of Ee, what percentage of gametes will have the E variant?	50%
What is a pungent square?	A genetic diagram to model possible combinations of genetic variants.
What's another type of a genetic diagram?	Family tree.
What is meant by a carrier?	Someone who has only one recessive variant. It is not expressed in their phenotype, but they can pass it down to offspring.

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	Created by lily bevan about 7 years ago