Drosophila has a diploid chromosome number of 2n = 8, wh...

Question

Drosophila has a diploid chromosome number of 2n = 8, which includes one pair of sex chromosomes (XX in females and XY in males) and three pairs of autosomes. Consider a Drosophila male that has a copy of the A₁ allele on its X chromosome (the Y chromosome is the homolog) and is heterozygous for alleles B₁ and B₂, C₁ and C₂, and D₁ and D₂ of genes that are each on a different autosomal pair. In the diagrams requested below, indicate the alleles carried on each chromosome and sister chromatid. Assume that no crossover occurs between homologous chromosomes.

For the metaphase I alignment shown in (c), what gamete genotypes are produced at the end of meiosis?

Accepted Answer

Hey, everyone. Let's take a look at this question together. The mitotic apparatus also known as the spindle apparatus is a complex structure that forms during mitosis. In eukaryotic cells, it consists of microtubules which are long thin fibers made up of tubulin proteins and associated proteins. What is the function of the spindle fibers during meta phase? Is it answer choice? A? It is involved in the separation of the sisters chromatis. Answer choice B, it is involved in the pairing of chromosomes during prophase. Answer choice C. It is responsible for the alignment of the chromosomes at the meta phase plate or answer choice D. All of the above. Let's work this problem out together to try to figure out which of the following answer choices describes the function of the spindle fibers during meta phase. So to solve this question, let's recall what we've learned about what happens during meta phase. So we know that in meta phase, which we know that meta phase is a stage of mitosis where the cell divides its nucleus and the chromosomes prepare for cell division. We have the replicated chromosomes are made up of two sister chromatid line up at the meta phase plate, which we know that the meta phase plate or the equatorial plane is that line down the center of the cell. And when we say that they line up at the meta phase plate, we're referring to the alignment of those chromosomes, which is due to the activity of the spindle fibers, which we know that the spindle fibers attached to the centromere. And we know that in anaphase, the spindle fibers hold the cytochrome tis to opposite poles of the cell, which we know that this process in anaphase does not happen if the process of alignment does not happen. And alignment is due to the activity of those spindle fibers, which means that the function of the spindle fibers during meta phase is that they are responsible for alignment, which means that answer choice C it is responsible for the alignment of the chromosomes at the meta phase plate is the correct answer because we know that in meta phase where we have our replicated chromosomes lining up at the meta phase plate, which is in the center of the cell is that process known as alignment, which the process of alignment does not occur without the help of the spindle fibers. So the function of the spindle fibers during meta phase is that they are responsible for the alignment of the chromosomes at the meta phase plate which is answer choice C. The correct answer, I hope you found this video to be helpful. Thank you and goodbye.

Key Concepts

Meiosis

Alleles and Genotypes

Chromosome Structure and Behavior

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