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

Can you explain about thoracic aortography, Q. Can you explain about thorac...

Q. Can you explain about thoracic Aortography? Aortic arch angiography has been used to assess aortic valve or aortic root disease. Thoracic aortography is helpful for assessm

Why are most ammoniotelic beings aquatic animals, Q. Why are most ammoniote...

Q. Why are most ammoniotelic beings aquatic animals? Aquatic animals like crustaceans, amphibian larvae and bony fishes generally are ammoniotelic since ammonia diffuses more e

Which substance starts clotting in humans after a wound, When a wound occur...

When a wound occurs in humans, platelets in the blood activate a substance that starts clotting process. The substance which starts clotting is: a) Adenosine (pron: ah-den-ah-s

To which direction does the growth of one side of a stem, To which directio...

To which direction does the growth of one side of a stem, branch or root induce the structure to curve? While one side of a stem, branch or root grows more than the other side

Contamination of the implant body before insertion, Contamination of the Im...

Contamination of the Implant Body before Insertion The implant may be contaminated by manufacturing error, by the operator, from non titanium instrumentation and by the bacteri

Classification of proteins based on chemical properties, Classification of ...

Classification of proteins based on chemical properties? Depending on their chemical properties and optical activity, the amino acids in proteins are classified under the follo

Agro-industrial byproducts, Agro-industrial byproducts Agro-industrial...

Agro-industrial byproducts Agro-industrial by-products in Southeast Asia are available in plenty, due to the emphasis on crop cultivation. By-products of agro-industries repre

Biological diversity of an ecosystem, Q. Is monoculture a system that contr...

Q. Is monoculture a system that contributes to great biological diversity of an ecosystem? The Monoculture implies that in a large area a single crop (only one species of plant

What is barr body genes, Q. What is Barr body Genes? Located inside nuc...

Q. What is Barr body Genes? Located inside nuclear envelope, it's a densely staining object which is an inactivated X chromosome in female mammalian cells. Most Barr body genes

Symptoms of serum sickness, Symptoms contain fever, weakness, rashes, with ...

Symptoms contain fever, weakness, rashes, with erythema and edema. Serum sickness depends on the immune difficult formed and the size of the complexes.

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