Question

List the possible allele combinations in the gametes produced by individuals with the following genotypes: A) AaAa B) CCdd CdCd C) XxYyXyYX

Answer 1

The possible gamete combinations for genotype AaBb are AB, Ab, aB, and ab. Homozygous genotypes produce identical gametes, whereas heterozygous genotypes can produce gametes with different allele combinations.

Step-by-step explanation:

Gamete Combinations from Genotypes

The student is asking about the types of gametes that can be produced by different genotypes. For genotype AaBb, the possible gamete combinations are AB, Ab, aB, and ab. Each gamete contains one allele from each gene due to the law of segregation during meiosis. The gametes represent all the possible ways that the alleles can be combined when passed to the offspring.

For genotypes such as CCdd and CdCd, only the alleles for the heterozygous gene pairs will create different gamete combinations. For instance, CdCd can produce gametes with Cd and dC due to independent assortment, which allows for different combinations of alleles for separate genes.

The phenotype is influenced by the genotype, and combinations like BB or bb are homozygous while Bb is heterozygous. Heterozygotes like Bb can produce gametes bearing either B or b alleles. During fertilization, the random combination of these gametes with those from another individual leads to the genotypic and phenotypic outcomes observed in offspring.

Answer 2

The possible allele combinations in the gametes are: "XY," "Xy," "xY," and "xy."

Correct answer C.

To determine the possible allele combinations in the gametes produced by individuals with the given genotypes, you need to consider the alleles present in each genotype and how they can segregate during meiosis to form gametes. Here are the possible allele combinations for each genotype:

A) AaAa:

- In this genotype, both alleles for a single gene (let's call it "Gene X") are heterozygous (Aa).

- During meiosis, the alleles can segregate, resulting in two types of gametes: one with allele "A" and one with allele "a."

- Therefore, the possible allele combinations in the gametes are: "A" and "a."

B) CCdd CdCd:

- In this genotype, there are two different genes involved: "Gene C" and "Gene D."

- "Gene C" is homozygous (CC), while "Gene D" is heterozygous (Cd).

- During meiosis, each gene segregates independently.

- For "Gene C," only one type of gamete can be produced: "C."

- For "Gene D," two types of gametes can be produced: "C" and "d."

- Therefore, the possible allele combinations in the gametes are: "C" and "Cd."

C) XxYyXyYX:

- In this genotype, there are two different genes on the X and Y chromosomes: "Gene X" and "Gene Y."

- Both genes have heterozygous alleles (Xx and Yy).

- During meiosis, the alleles for "Gene X" segregate independently from the alleles for "Gene Y."

- For "Gene X," two types of gametes can be produced: "X" and "x."

- For "Gene Y," two types of gametes can also be produced: "Y" and "y."

These are the possible allele combinations in the gametes for each of the given genotypes based on Mendelian segregation principles and the specific alleles present in each genotype.