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.
It is b because of all the cells that produce the chemical bond
Whole blood has 4 major components;
Plasma
Red Blood Cells
White Blood Cells
Platelets
Answer:
A source from which organisms generally take elements is called exchange pool (option B).
Explanation:
Options for this question are:
- <em>Food web.</em>
- <em>Exchange pool.</em>
- <em>Reservoir.</em>
- <em>Biotic community.</em>
The term exchange pool is related to the biogeochemical cycles that exist in nature, referring to the source from which elements present in the environment become part of living organisms.
<u>Exchange pools are the biotic components</u> -like animals and plants- of an ecosystem, which determine the passage of elements between living beings. An element can remain as a reservoir (abiotic) in the soil, and then be incorporated into the exchange pool.
