Answer:
allopolyploidy
Explanation:
Polyploidy is the condition by which a cell might have more than two chromosome sets that form homologous pairs. It might occur due to a failure or abnormality in cell division.
Autopolyploidy
Refer to a type of polyploidy in which an organism has more than two copies of homologous chromosomes. It results from the duplication of a group of chromosomes of the same species. Autopolyploid individuals have <u>at least three groups of homologous chromosomes</u>. Autopolyploidy is produced by the<u> gamete fusion of the same progenitor - same species</u>-, duplicating the number of chromosomes of diploid species. The autopolyploid cell has groups of homologous chromosomes. Autopolyploidy is produced mainly due to non-disjunction during meiosis.
Allopolyploidy
Refer to another type of polyploidy in which species have more than three sets of chromosomes in their cells. Allopolyploidy <u>occurs when two different species mate</u>, leading to the fusion of gametes that belong to different species and produce a new hybrid. The chromosomic complement has more than two copies of chromosomes. The hybrid is infertile with the parental species. The allopolyploid cells have chromosome groups that are not homologous.
In the exposed example two different species mate and produce a hybrid species.
Equation B has all 4 quantities.
Answer:
D. Sterility Locus
Explanation:
Angiosperms have several mechanisms to prevent self-pollination due to the advantage of cross-pollination. One of such mechanisms is self-incompatibility genes present on the sterility locus.
These genes determine the germination of the pollen on the stigma. If both the pollen and stigma carry the same allele of the gene present at the sterility locus, the germination of pollen is prevented.
The sterility locus has multiple alleles and the presence of the same alleles at the same locus in both pollen and stigma prevents the pollen germination.
For example, pollen from S1S2 individuals can not germinate on the stigma with the S1S3 genotype. Here, the pollen does not obtain water as required for germination from the stigma and are unable to germinate.
