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

Ecology, importance of pyramid of energy to the ecologist

importance of pyramid of energy to the ecologist

What do you mean by overgloves, Q. What do you mean by Overgloves? The ...

Q. What do you mean by Overgloves? The purpose of these gloves is to use time more efficiently and to protect the skin on the hands through minimizing the number of times that

Determine the procedure of armamentarium, Determine the Procedure of Armame...

Determine the Procedure of Armamentarium 1. Make an impression of the mandibular ridge and pour the cast in type 3 gypsum 2. Apply separating medium and allow it to dry 3

What are the penetrance and the expressivity of a gene, What are the penetr...

What are the penetrance and the expressivity of a gene? The Individuals that carry a same genotype don't always manifest in an identical manner the correspondent phenotype. The

Nervous system - cranial nerves, CRANIAL NERVES 12 pairs. Total weig...

CRANIAL NERVES 12 pairs. Total weight 12 gms. Upto amphibian 10 pairs cranial nerves are present. 1, 2, 8, - sensory. 3, 4, 6, 11, 12, motor. 5, 7, 9, 10 - mixed. 3

Codon, Codon is the group of three consecutive nucleotides within the mess...

Codon is the group of three consecutive nucleotides within the messenger RNA (mRNA) which encodes a message to initiate translation, to incorporate the specific amino acid into th

Describe the term - intellectual processes scales, Describe the term - Inte...

Describe the term - Intellectual Processes scales The 269 items are divided into 11 content scales, each of which may be administered individually. Since these scales contain v

State the term in brief -asconoid sponge, State the term in brief -Asconoid...

State the term in brief -Asconoid sponge? Of the three different sponge architectures, it is the simplest. It comrpsies a central choanocyte lined spongocoel which opens to the

The permissible use of the technique amniocentesis, The permissible use of ...

The permissible use of the technique amniocentesis is for: 1. detecting sex of the unborn foetus 2. artificial insemination 3. transfer of embryo into the uterus of the su

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