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

Why in the preparation of a karyotype analysis, Why in the preparation of a...

Why in the preparation of a karyotype analysis is the use of a substance like colchicine interesting? The Colchicine is a substance that disallows the formation of microtubules

What are the two big groups into which cells are classified, Cells are clas...

Cells are classified into eukaryotic or prokaryotic. Prokaryotic cell is that with no a delimited nucleus. Eukaryotic cells are those with nucleus delimited by membrane.

Lymph, LYMPH - Lymph is a mobile connective tissue comprising lymph pla...

LYMPH - Lymph is a mobile connective tissue comprising lymph plasma (fluid) and lymphcorpuscles (cells).   COMPOSITIO N - (i )      Lymph Plasma - It is simil

Explain the stages in taxonomic procedures - gamma taxonomy, Explain the st...

Explain the stages in taxonomic procedures - Gamma Taxonomy This phase of taxonomy is also called biological taxonomy and is concerned with the study of speciation. It is inclu

How are gases exchanged in sponges, Q. How are gases exchanged in sponges? ...

Q. How are gases exchanged in sponges? The gas exchange in sponges happens by diffusion from the exterior to the cells that absorb molecular oxygen and liberate carbon dioxide.

Plant physiology, application of apical dominace in horticulture and agricu...

application of apical dominace in horticulture and agriculture short notes

What are the hormones that release of the female gamete, What are the hormo...

What are the hormones that promote the release of the female gamete from the follicle and at which day of the menstrual cycle does this phenomenon happen? What is this event called

Explain about gestational diabetes mellitus, Q. Explain about Gestational D...

Q. Explain about Gestational Diabetes Mellitus ? During pregnancy, a woman who does not have a history of diabetes, may develop high blood glucose or sugar. This is GDM. The di

What do you mean by an antibiogram, Q. What is an antibiogram? The Anti...

Q. What is an antibiogram? The Antibiogram is a laboratory test intended to guide the choice of sufficient antibiotic to treat a given bacterial infection. In an Antibiogram cu

Determine the significance of siphuncle., Determine the significance of Sip...

Determine the significance of Siphuncle. A cord of tissue that passes between different chambers of a Nautilid shell. Siphuncle regulates the amount of air or fluid in chambers

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