/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 20 Are mitotic recombinations and s... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 5: Problem 20

Are mitotic recombinations and sister chromatid exchanges effective in producing genetic variability in an individual? in the offspring of individuals?

Short Answer

Expert verified
Short Answer: Mitotic recombinations and sister chromatid exchanges can generate some genetic variability within an individual, but their overall contributions to genetic variability in the offspring are limited. Mitotic recombinations create new genetic combinations in chromosomes, but only affect offspring if the changed chromosome is involved in gamete formation during meiosis. Sister chromatid exchanges involve swapping identical genetic material between sister chromatids, thus not introducing new genetic variations in offspring.

Step by step solution

01

Define Mitotic Recombination

Mitotic recombination is an event that occurs during the mitotic cell cycle, in which genetic material is exchanged between homologous chromosomes. This process leads to two parental chromosomes exchanging a portion of their DNA, resulting in new combinations of genetic information within the chromosomes.
02

Define Sister Chromatid Exchange

Sister chromatid exchange is a process that occurs during the cell cycle where genetic material is exchanged between two identical sister chromatids of a replicated chromosome. This process can occur during both mitosis and meiosis and can lead to the exchange of genetic information between chromatids.
03

Explain Genetic Variability in an Individual

Genetic variability is the presence of different genetic information within an individual, which can lead to variations in traits, characteristics, and other features. It can arise from various sources like mutations, recombination, and the mixing of genetic information during sexual reproduction.
04

Analyze the effectiveness of mitotic recombination in producing genetic variability

Mitotic recombination can result in genetic variation within an individual by creating new combinations of genetic information on the chromosomes. However, mitotic recombination doesn't have a substantial impact on an individual's offspring, since the genetic material that underwent recombination will only be passed on if the affected chromosome is involved in gamete formation during meiosis. This means that while mitotic recombination can contribute to genetic variability in an individual, its overall effect on genetic variability in the offspring is limited.
05

Analyze the effectiveness of sister chromatid exchange in producing genetic variability

Sister chromatid exchange can generate genetic variability within an individual during mitosis or meiosis, presenting new genetic combinations on the sister chromatids. However, because sister chromatids are identical and the exchanged genetic material between them is also identical, sister chromatid exchange doesn't introduce new genetic variations. Therefore, while sister chromatid exchange may play a role in the maintenance of genetic information within an individual, it doesn't significantly contribute to genetic variability in the offspring. In conclusion, mitotic recombinations and sister chromatid exchanges can produce minor genetic variability within an individual, but their contributions to genetic variability in the offspring are limited.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

In this chapter, we focused on linkage, chromosomal mapping, and many associated phenomena. In the process, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, what answers would you propose to the following fundamental questions? (a) How was it established experimentally that the frequency of recombination (crossing over) between two genes is related to the distance between them along the chromosome? (b) How do we know that specific genes are linked on a single chromosome, in contrast to being located on separate chromosomes? (c) How do we know that crossing over results from a physi- cal exchange between chromatids? (d) How do we know that sister chromatids undergo recombination during mitosis? (e) When designed matings cannot be conducted in an organism (for example, in humans), how do we learn that genes are linked, and how do we map them?

Colored aleurone in the kernels of corn is due to the dominant allele \(R\). The recessive allele \(r,\) when homozygous, produces colorless aleurone. The plant color (not the kernel color) is controlled by another gene with two alleles, \(Y\) and \(y\). The dominant \(Y\) allele results in green color, whereas the homozygous presence of the recessive \(y\) allele causes the plant to appear yellow. In a testcross between a plant of unknown genotype and phenotype and a plant that is homozygous recessive for both traits, the following progeny were obtained: $$\begin{array}{lc} \text { colored, green } & 88 \\ \text { colored, yellow } & 12 \\ \text { colorless, green } & 8 \\ \text { colorless, yellow } & 92 \end{array}$$ Explain how these results were obtained by determining the exact genotype and phenotype of the unknown plant, including the precise arrangement of the alleles on the homologs.

DNA markers have greatly enhanced the mapping of genes in humans. What are DNA markers, and what advantage do they confer?

Another cross in Drosophila involved the recessive, X-linked genes yellow \((y),\) white \((w),\) and \(c u t(c t) .\) A yellow-bodied, white-eyed female with normal wings was crossed to a male whose eyes and body were normal but whose wings were cut. The \(\mathrm{F}_{1}\) females were wild type for all three traits, while the \(\mathrm{F}_{1}\) males expressed the yellow-body and white- eye traits. The cross was carried to an \(\mathrm{F}_{2}\) progeny, and only male offspring were tallied. On the basis of the data shown here, a genetic map was constructed. (a) Diagram the genotypes of the \(\mathrm{F}_{1}\) parents. (b) Construct a map, assuming that white is at locus 1.5 on the X chromosome. (c) Were any double-crossover offspring expected? (d) Could the \(\mathrm{F}_{2}\) female offspring be used to construct the map? Why or why not?

In a series of two-point mapping crosses involving five genes located on chromosome II in Drosophila, the following recombinant (single-crossover) frequencies were observed: $$\begin{array}{lc} p r-a d p & 29 \% \\ p r-v g & 13 \\ p r-c & 21 \\ p r-b & 6 \\ a d p-b & 35 \\ a d p-c & 8 \\ a d p-r g & 16 \\ v g-b & 19 \\ v g-c & 8 \\ c-b & 27 \end{array}$$ (a) Given that the adp gene is near the end of chromosome II (locus 83 ), construct a map of these genes. (b) In another set of experiments, a sixth gene, \(d\), was tested against \(b\) and \(p r\) $$\begin{array}{ll} d-b & 17 \% \\ d-p r & 23 \% \end{array}$$ Predict the results of two-point mapping between \(d\) and \(c, d\) and \(v g,\) and \(d\) and \(a d p\)
See all solutions

Recommended explanations on Biology Textbooks

Control of Gene Expression

Read Explanation

Biological Structures

Read Explanation

Genetic Information

Read Explanation

Ecological Levels

Read Explanation

Biological Processes

Read Explanation

Communicable Diseases

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.