Changes in chromosome number, Biology

Aneuploidy : One or inore chron~osomes of a normal set nlay bc lacking or present in excess. The term riullison~y refers to absence of both the chromosomes of a pair. Monosomy, trisomy, tetrasomy etc., refer to the occurrence of a given chromosome once, thrice, four times ctc., resycctively in a diploid organism.

Polyploidy : Refers to the occurrence of more than two sets of chromosomes in an individual. Most organisms are diploid, that is they have two sets of chromosomes in their somatic cells, but only one in their gametic cells. Polyploid organisms would be triploid when they have three sets of chromosomes, tetraploid if they have four sets and so on. Polyploidy occurs frequently in plants but is a rare phenomenon in animals. Polyploidy has been a common means of speciation in plants. Many of thc cultivated plants, such as wheat, oats, tobacco, potato, banana, coffee, sugarcane and many flowering plants are polyploids.

Plant breeders always attempt to induce polyploidy by artificial means to create new varieties. Polyploidy can be regarded as thc only means in bisexual organisms by which a new species could arise in one step.

Posted Date: 4/6/2013 1:13:05 AM | Location : United States







Related Discussions:- Changes in chromosome number, Assignment Help, Ask Question on Changes in chromosome number, Get Answer, Expert's Help, Changes in chromosome number Discussions

Write discussion on Changes in chromosome number
Your posts are moderated
Related Questions
DISORDER OF SKELETON AND JOINTS - 1 .      Sprain - It involves a stretching or tearing of tendons or ligaments. 2.      Arthritis - It is infalmation of joints.

Does the trend of the change in shape of the graph as temperature increases differ when a different gas is examined?

Seed Coat Effects In some seeds dormancy is imposed by the presence of the seed coat; if this is removed, the seed germinates. Two possible types of mechanisms could be invol

Telenursing Telenursing refers to the exchange of expertise in various areas like nursing diagnosis data over a distance. It is divided into the following categories: a)

If a diploid sperm fertilized a haploid egg, what would the result be? a.Haploid (n) b.Diploid (2n) c.A mixture of diploid (2n) and haploid (n) d.Triploid (3n)

Q. What is coronary bypass graft? The Coronary artery bypass graft is a kind of surgical myocardial revascularization that is a way to provide blood to a myocardium whose blood

Explain HIV/AIDS HIV/AIDS is another example of  chronic infections.  Its existence was discovered recently in 1981. The spread  of  HIV infection  is widespread  and  can  pro

How can the age of a tree be estimated from the analysis of the rings present on a cross section of its stem? For the growth of the tree it is essential to have formation of ne

Q. Monounsatuated fats required for dyslipidemia? Monounsatuated fats (MUFA): These are liquid at room temperature, the highest food source being olive oil, canola oil, rapesee

A Complex  of  elongation  factor  EF-G  (also known as  translocase)  and  GTP example for  EF-G/GTP binds  to the  ribosome.  There are three concerted movements  now happen coll