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

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.

What are the genotypes of the daughter cells?

Accepted Answer

Welcome back everyone. Our next question says, assuming a parent cell has three pairs of homologous chromosomes, each with two different all having genotype. That's heterozygous, 43 genes G H and I during mitosis, the spindle fibers pull the sister chromatid apart and each daughter cell receives one copy of the replicated chromosome. Which of the following statements about the genotype of the daughter cells is correct choice. A, a haploid genotype of heterozygous for G H and I with one copy of each chromosome and two identical sisters chromatis per chromosome. Choice B. The genotype of each daughter cell would be heterozygous for G H and I as each daughter cell receives identical copies of each chromosome from the parent cell and try a haploid genotype of heterozygous for each G H and I with two copies of each chromosome and two identical sisters chromatid per chromosome and choice D A unique haploid genotype resulting from a random asom assortment of chromosomes. Well, we've got a lot of words here, a lot of different choices. But if we zoom in on one key thing in this question, we will quickly get to our correct answer. And that is that we are talking about mitosis. And of course, in mitosis, we produced two identical daughter cells who are also genetically identical to the parent cell. And that means that they have to be diploid cells. So they're genetically identical to the parent. So they have to be diploid cells. It's meiosis that leads to haploid daughter cells who are genetically distinct from each other. So when we look through our answer choices, we let's look at choice. A right away. It says a haploid genotype. Well, it can't be haploid. We need diploid cells. So choice A is not correct choice. B the genotype of each daughter cell would be heterozygous for each gene as each daughter cell receives identical copies of each chromosome from the parent cell. And that is the correct description of what happens in mitosis. You should have a genotype exactly the same as the parent cell, which is given to us in our problem. In choice C it says a haploid genotype. So again, that's not going to be the case in mitosis. Choice C is not correct. We don't even have to go any further and also says a unique haploid genotype. There's our problem. Again, we do not have haploid genotypes in the daughter cells resulting from mitosis of diploid parents. So what's our genotype of the daughter cells? Choice B, the genotype of each daughter cell would be heterozygous for G H and I as each daughter cell receives identical copies of each chromosome from the parent cell. See you in the next video.

Key Concepts

Chromatids and Chromosomes

Homologous Chromosomes

Genotype and Alleles

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