Biology: Genetics Review

What is the best definition of genotype?

• the physical appearance of an organism

• set of alleles for a given trait

What is an allele?

• an alternative form a gene

• the correct form a gene

• a mutated form a gene

• the gene that is expressed

Which genotype represents a recessive trait?

• PP

• Pp

• pp

Recessive traits are always homozygous.

• True

• False

Which statement is true of a plant with genotype TT and another with genotype Tt?

• each would have differing phenotypes

• all alleles are dominant

• all alleles are recessive

• both have the same phenotype

Which statement is true of the plant offspring using the Punnett Square above

• 50% of the offspring will be short

• 100% of the offspring will be dominant

• 75% of the offspring will be tall.

• 25% of the offspring will be tall.

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Which is an example of incomplete dominance?

• the adult height of a human

• Blood types

• hair color in humans

• a pink snap dragon flower with red and white parents

The law of segregation states that ________.

• alleles for different traits are distributed independently

• only one form of the trait will appear in the offspring

• allele pairs separate during gamete formation

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____ of offspring would have the same phenotype as the parents if the cross was Yy by Yy?

• 25%

• 50%

• 75%

• 100%

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What is the ratio of offspring when 2 heterozygous plants (Tt) for a certain trait are crossed?

• 50% TT : 50% Tt

• 50% TT : 50% tt

• 100% TT : 0% tt

• 25% TT : 50% Tt : 25% tt

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