From a piece of blank paper, cut out three sets of four cigar-...

Question

From a piece of blank paper, cut out three sets of four cigar-shaped structures (a total of 12 structures). These will represent chromatids. Be sure each member of a set of four chromatids has the same length and girth. In set one, label two chromatids 'A' and two chromatids 'a.' Cut each of these chromatids about halfway across near their midpoint and slide the two 'A' chromatids together at the cuts to form a single set of attached sister chromatids. Do the same for the 'a' chromatids. In the second set of four chromatids, label two 'B' and two 'b.' Cut and slide these together as you did for the first set, joining the 'B' chromatids together and the 'b' chromatids together. Repeat this process for the third set of chromatids, labeling them as 'D' and 'd.' You now have models for three pairs of homologous chromosomes, for a total of six chromosomes. Give the genotype of the cell with six chromosomes.

Accepted Answer

Hey, everyone. Let's take a look at this question together. A heterozygous diploid cell has two pairs of homologous chromosomes. Each carrying three alleles for a given gene. If one pair has the genotype, dominant X, dominant Y, recessive Z and the other pair has the genotype, recessive X dominant Y and recessive Z. What are the possible genotypes of the cells? Cys chromatis? Is it answer choice? A dominant X, recessive Y and Z as well as recessive X and Y and dominant Z and recessive X dominant Y. Recessive Z answer choice B, recessive X, dominant Y and Z as well as dominant X and Y and recessive Z and recessive X Y Z answer choice C dominant, X, recessive Y and Z. Recessive X Y and Z and dominant X recessive Y dominant Z or answer choice D dominant, X, recessive Y dominant, Z, dominant, X, recessive Y and Z and recessive X Y and Z. Let's work this problem out together to try to figure out which of the following answer. Choices contains all of the possible genotypes of the cells sisters chromatis. So we know that during meiosis homologous chromosomes separate and each daughter. So receives one of each chromosome and we also know that the sister chrome separate and each, yeah, me, yes, one copy of each gene. And so we have homologous chromosome one and we have homologous chromosome two, which we note that one pair has a genotype of dominant X and dominant Y with recessive Z and the other has recessive X, dominant Y and recessive Z. So we have dominant X, dominant Y and recessive Z and we have recessive X dominant Y and recessive Z, which means that the genotypes that we can have from our first pair are dominant X, recessive Y and recessive Z as well as recessive, X perceive Y and dominant Z. And then from our other pair, the genotype that we can have is that recessive X dominant Y and recessive Z, which means that all of the possible genotypes of the cell cytochrome tis are dominant, X, recessive Y. Recessive Z. Recessive X, recessive Y, dominant Z and recessive X dominant Y and recessive Z. Which means that answer choice. A is the correct answer because we know that the possible genotypes of the cy chromatis are determined by the alleles present on each of the homologous chomos themes. So, homologous chromosome one as the all's dominant X dominant Y and recessive Z and can produce two types of cytochrome tis dominant X, recessive Y, recessive Z and recessive X, recessive Y dominant Z and our homologous chromosome two as the allele's recessive X dominant Y, recessive Z and can produce one type of cytochrome recessive, X dominant Y and recessive Z. Thus giving us the three possible genotypes which are dominant, X, recessive, Y, recessive Z, recessive X, recessive Y dominant Z and recessive X dominant Y recessive Z which makes answer choice. A the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Chromatids

Homologous Chromosomes

Genotype

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