Question 1:
In a monohybrid cross between two heterozygous individuals (Aa x Aa), what is the phenotypic ratio of the offspring?
Explanation: B) The phenotypic ratio of the offspring in a monohybrid cross between two heterozygous individuals (Aa x Aa) is 3:1. This means that for every three individuals with the dominant phenotype, there will be one individual with the recessive phenotype.
Question 2:
In a dihybrid cross between two heterozygous individuals (AaBb x AaBb), what is the phenotypic ratio of the offspring?
Explanation: D) The phenotypic ratio of the offspring in a dihybrid cross between two heterozygous individuals (AaBb x AaBb) is 9:3:3:1. This means that for every nine individuals with both dominant phenotypes, there will be three individuals with one dominant and one recessive phenotype, three individuals with the other dominant and recessive phenotype, and one individual with both recessive phenotypes.
Question 3:
In a cross between a homozygous dominant individual (AA) and a homozygous recessive individual (aa), what will be the genotypic ratio of the offspring?
Explanation: A) The genotypic ratio of the offspring in a cross between a homozygous dominant individual (AA) and a homozygous recessive individual (aa) is 1:1. All offspring will have the genotype Aa, with one allele from each parent.
Question 4:
In a cross between two individuals heterozygous for two different traits (AaBb x AaBb), how many different genotypes can be produced in the offspring?
Explanation: D) In a cross between two individuals heterozygous for two different traits (AaBb x AaBb), 16 different genotypes can be produced in the offspring. This is because each parent can contribute one of two alleles for each of the two traits, resulting in 2^2 = 4 possible combinations of alleles for each trait. Multiplying the possibilities for each trait (4 x 4), we get 16 different genotypes.
Question 5:
In a test cross, an individual with a dominant phenotype but unknown genotype is crossed with a homozygous recessive individual. If all the offspring show the dominant phenotype, what can be concluded about the genotype of the unknown individual?
Explanation: A) If all the offspring of a test cross between an individual with a dominant phenotype but unknown genotype and a homozygous recessive individual show the dominant phenotype, it can be concluded that the unknown individual is homozygous dominant. If the unknown individual were heterozygous, some of the offspring would show the recessive phenotype.
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