Gene and Chromosome Mutation.
> Chromosome Mutations
Euploidy
Euploidy is one of the two types of chromosome mutations which involves a change in the number of whole sets of chromosomes. The diploid number of chromosomes is the number of sets that are established at fertilisation. There are mutations that result in an increased number of diploid sets of chromosomes called polyploidy which arises spontaneously is common in plants (mainly in flowering plants) but relatively rare in animals. A polyploid is an organism that possesses three or more sets of chromosomes in cases where the normal complement is two sets. Many crop plants are natural polyploids such as durum wheat and common wheat which have four and six sets of chromosomes respectively. Matings between polyploid and diploid individuals are invariably sterile, however, in the case of plants some which are able to self fertilise can do so. Once a polyploid population is established then they can reproduce as normal. If the polyploid is based upon sets of chromosomes from the same species, it is an autopolyploid. These are most likely to have arisen by spontaneous doubling following the failure of a spindle to form or to function correctly at meiosis.
Aneuploidy
> Chromosome Mutations
Euploidy
Euploidy is one of the two types of chromosome mutations which involves a change in the number of whole sets of chromosomes. The diploid number of chromosomes is the number of sets that are established at fertilisation. There are mutations that result in an increased number of diploid sets of chromosomes called polyploidy which arises spontaneously is common in plants (mainly in flowering plants) but relatively rare in animals. A polyploid is an organism that possesses three or more sets of chromosomes in cases where the normal complement is two sets. Many crop plants are natural polyploids such as durum wheat and common wheat which have four and six sets of chromosomes respectively. Matings between polyploid and diploid individuals are invariably sterile, however, in the case of plants some which are able to self fertilise can do so. Once a polyploid population is established then they can reproduce as normal. If the polyploid is based upon sets of chromosomes from the same species, it is an autopolyploid. These are most likely to have arisen by spontaneous doubling following the failure of a spindle to form or to function correctly at meiosis.
Aneuploidy