CROSSING OVER

The process, which produces recombination of genes by interchanging the corresponding segments between nonsister chromatids of homologous
chromosomes, is called crossing over. A crossing over between linked genes allows their recombination during meiosis.
Crossing over takes place in pachytene stage of prophase I of meiosis. In pachytene stage, the bivalent chromosome becomes tetrad i.e. with four chromatids. The adjacent nonsister chromatids are joined together at certain points called chiasmata. Crossing over occurs between the nonsister chromatids of paired chromosomes in the region of chiasma. At each chiasma, the two nonsister chromatids break, exchange their segments
and rejoin resulting the crossing over.
Hence, out of four chromatids the two adjacent chromatids are recombinants and other two are original chromatids. Thus four types of
gametes are obtained.

Significance of crossing over
1. Crossing over leads to the production of new combination of genes and provides basis for obtaining new varieties of plants.
2. It plays an important role in the process of evolution.
3. The crossing over frequency helps in the construction of genetic maps
of the chromosomes.
4. It gives us the evidence for linear arrangement of linked genes in a
chromosome.

Disclaimer
This channel does not promote or encourage any illegal activities.
All contents provided by this channel for general and education purpose only.
Copyright disclaimer under section 107 of the copyright act 1976,allowance is made for "fair use policy" for purposes such as criticism, comment, news reporting,teaching,scholarship and research. Fair use is a use permitted by copyright statute that might otherwise be infringing. Non-profit, educational or personal use tips the balance in favor of fair use.

[rdway]

Great explanation but I don't understand how does the crossing over frequency help in the construction of genetic map and give us the evidence of linear arrangement of linked genes in a chromosome.

[harshvardhan]

During, crossover exchange of genes occur or exchange of chromosome sets occur, please clarify.

[atoptreetops]

Best illustration of this process, thank you

[LoneWolf-ncfb]

Superb teaching it really helped me 😍, I recommend u to make more videos on genetics especially about dna chromosomes

[randomnaga]

The process which produces recombination of genes by interchanging the corresponding segment between non sister chromatids of homologous chromosome is called crossing over

[drd]

Very nice, please make more videos related to Molecular biology, genetics and r DNA technology, etc.

[maisalkhan]

I will be very happy because i have clear the concept of gene

[moribundmurdoch]

I associate that intro music with the YouTube channel "Abroad in Japan".

[moggers]

Thank u for explains the significance that’s exactly what I was looking for (: