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
Unlike bilaterally symmetrical animals, radially symmetrical animals are almost never able to move themselves from place to place. Why might it have been so difficult for radially

Select all that are true/correct: Cellular respiration consists of the production of ATP in several steps using enzymes. Photosynthesis produces carbohydrates using carbon dioxide


A lk a l in e indigestion The disease occurs due to the consumption of excessive amount of protein rich concentrate or non protein nitrogenous substance like urea, and is

Define Theophrastus of Eresus - Taxonomy The Father of Botany (370-285 B.C.); of all the men who ever lived upon the earth certainly one of the most remarkable was Theophrastu

Q. Vitamins and minerals requirement in chronic diarrhoea? Loss of vitamins is related to the degree of mucosal damage in chronic diarrhoea, which in turn impairs absorption an

Blood Collection: Blood for analysis may be obtained from veins, arteries, or capillaries. Venous blood is usually the specimen of choice, and venipuncture is the method for

Q. What are the pancreatic tissues involved respectively in the endocrine and exocrine secretions? What are their respective hormones and enzymes? The exocrine secretion of the

i need help with to do a pedigree charts.

Under conditions when a cell only needs to use the nonoxidative portion of the Pentose Phosphate pathway to synthesize ribose-5-phosphate, the elevated levels of NADPH in the cell