Explain about crossing over, Biology

Assignment Help:

What is crossing over? How is meiosis related to this phenomenon?

Linked alleles, for instance, A-b and a-B, form the gametes A-b and a-B that maintain the linkage of the alleles. This type of linkage is known as complete linkage. In the first division of meiosis (meiosis I) however the crossing over phenomenon may happen. Chromosomes from a pair of homologous may exchange extremities and some once linked alleles, for instance, A-b and a-B, recombine to form dissimilar gametes, in the case, A-B and a-b.

Crossing over may occur when the arms of the chromatids of each homologous are paired during meiosis. Matching portions of the extremities of two nonsister chromatids (one from one homologous of the pair) break and the pieces are exchanged, each of them becoming part of the arm of the other chromatid. For instance, if the allele A is situated in a side of the arm relating to the point of breaking and the allele b is located in the other side, they will be separated and gametes A-B and a-b will be produced, instead of A-b and a-B.

 


Related Discussions:- Explain about crossing over

Resemble the homozygous recessive parental, A dihybrid cross yields 320 F2 ...

A dihybrid cross yields 320 F2 offspring. How many are expected to resemble the homozygous recessive parental?

What is pupillary reflexes, Pupillary reflexes There are two types of r...

Pupillary reflexes There are two types of reflexes which control the pupillary reaction-the light reflex and near reflex. When light is shown on one eye, there is a constrictio

What are angiosperms, What are angiosperms, the flowering plants? What is t...

What are angiosperms, the flowering plants? What is the major feature that distinguishes them from the gymnosperms? Flowering plants have flowers and seeds (phanerogamic plants

Estimate the results of tetralogy of fallot, Estimate the Results of Tetral...

Estimate the Results of Tetralogy of Fallot? In excellent centres, the mortality is reported one per cent or less. In infants and babies with low weight, higher mortality is ex

Give source organism of the dna polymerase used in pcr, a) Mention the numb...

a) Mention the number of primers needed in each cycle of polymerase chain Reaction (PCR) . Write the role of primers and DNA polymerase in PCR. b) Give the characteristic fea

Define about the glutathione peroxidases - selenium, Define about the Gluta...

Define about the Glutathione peroxidases - Selenium? The role of selenium in the cytosolic enzyme, glutathione peroxidase (GSHPx), was first illustrated in 1973. Four selenium

How to compare and contrast acids, Compare and contrast acids and bases in ...

Compare and contrast acids and bases in terms of their H+ ion and OH- ion concentrations.

Explain the frenal and muscle attachments, Frenal and Muscle Attachments: ...

Frenal and Muscle Attachments: Frenal attachment at the site of implant placement has to be evaluated. A high frenal attachment may have a definite pull on the gingival surroun

Why and how does the food get spoiled, Why and how does the food get spoile...

Why and how does the food get spoiled? There are several causes of food spoilage. These include: Growth of Microorganisms, such as bacteria, molds and yeasts, which can

What is particularly of the mucous membranes, How would carbon monoxide poi...

How would carbon monoxide poisoning affect a person's coloring, particularly of the mucous membranes? How would it affect the hemoglobin concentration, hematocrit, and percent oxyh

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd