POLYPLOIDY
The organisms having haploid sets of chromosome in multinumber in body cells are called polyploid and this phenomenon is called as polyploidy.
The organism having :
1 sets of haploid chromosome: haploid
2 sets of haploid chromosome:diploid
3 sets of haploid chromosome:triploid
polyploidy is most common in plants than in animals.
Types of polyploidy :
a) autopolyploidy: it is the polyploidy in which the homologous haploid sets of chromosomes are multiplied in numbers.it occurs in individuals of same species. eg: banana,grapes
b)allopolyploidy: it is the polyploidy in which the haploid sets of chromosome is multiplied in the hybrids.it occurs between the individuals of two or more different species.eg : raphano brassica,liger,tigon,mule,pomato etc.
polyploidy in animals : polyploidy is rare in animals. it occurs sometimes in leech,flatworms. polyploidy in human is seen in liver and cancer cells.
Role of polyploids :
1. it is one of the sources of variation and thus help in evolution of new varities,species and genera.
2.it is often associated with advantageus features like increased size,hardness and disease resistance. this is called hybrid vigour.
3.seedless variety of watermelon,tomatto,grapes etc can be produced.
4.drought resistance and high yielding species of crop plants such as hybrid wheat,pady are produced by allopolyploidy.
5.it is used in obtaining fodder plants.
6.polyploids have more morphological,genetical and physiological advancement over a normal diploid plant.
The organisms having haploid sets of chromosome in multinumber in body cells are called polyploid and this phenomenon is called as polyploidy.
The organism having :
1 sets of haploid chromosome: haploid
2 sets of haploid chromosome:diploid
3 sets of haploid chromosome:triploid
polyploidy is most common in plants than in animals.
Types of polyploidy :
a) autopolyploidy: it is the polyploidy in which the homologous haploid sets of chromosomes are multiplied in numbers.it occurs in individuals of same species. eg: banana,grapes
b)allopolyploidy: it is the polyploidy in which the haploid sets of chromosome is multiplied in the hybrids.it occurs between the individuals of two or more different species.eg : raphano brassica,liger,tigon,mule,pomato etc.
polyploidy in animals : polyploidy is rare in animals. it occurs sometimes in leech,flatworms. polyploidy in human is seen in liver and cancer cells.
Role of polyploids :
1. it is one of the sources of variation and thus help in evolution of new varities,species and genera.
2.it is often associated with advantageus features like increased size,hardness and disease resistance. this is called hybrid vigour.
3.seedless variety of watermelon,tomatto,grapes etc can be produced.
4.drought resistance and high yielding species of crop plants such as hybrid wheat,pady are produced by allopolyploidy.
5.it is used in obtaining fodder plants.
6.polyploids have more morphological,genetical and physiological advancement over a normal diploid plant.
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