Everything about Homologous Chromosome totally explained
Homologous chromosomes are
chromosomes in a
biological cell that pair (
synapse) during
meiosis, or alternatively, non-identical chromosomes that contain information for the same biological features and contain the same
genes at the same
loci but possibly different genetic information, called
alleles, at those genes. For example, two chromosomes may have genes encoding eye color, but one may code for brown eyes, the other for blue.
Non-homologous chromosomes representing all the biological features of an organism form a set, and the number of sets in a cell is called
ploidy. In
diploid organisms (most plants and animals), each homologous chromosome is
inherited from a different
parent. But
polyploid organisms have more than two homologous chromosomes.
Homologous chromosomes are similar in length, except for
sex chromosomes in several
taxa, where the
X chromosome is considerably larger than the
Y chromosome. These chromosomes share only small regions of
homology.
Humans have 22 pairs of homologous non-sex chromosomes (called
autosomes). Each member of a pair is inherited from one of their two parents. In addition, female humans have a homologous pair of
sex chromosomes (
2 X's); males have an
X and a
Y chromosome.
Homologous chromosomes are two pairs of sister,and brothers chromatids that have gone through the process of crossing over and meiosis. In this process the homologous chromosomes cross over (not the sister chromatids)each other and exchange genetic information. This causes each final cell of meiosis to have genetic information from both parents. It also causes genetic variation, but that's a different topic.The homologous chromosomes are similar in length.
Other terms
Homologous chromosomes are not to be confused with
sister chromatids, the identical chromosomes that separate during
mitosis or
meiosis II.
Homology of chromosomes is different than
homology of genetic sequences, and predates that use of the term
homology. An exception arises with
allopolyploidy where chromosomes pair up by age, so sequence similarity is used to determine the original chromosomal sets.
Homologous chromosomes are also very similar to, and often confused with the term
synteny (or gene homology)—which refers to genes located on the same section of chromosome between individuals of the same or different species.
Further Information
Get more info on 'Homologous Chromosome'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://homologous_chromosome.totallyexplained.com">Homologous chromosome Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |
