Answer: Nucleotide; Adenine
Explanation: RNA Nucleotide contains bases of Thymine, Cytosine, Guanine and Uracil. The Uracil base in RNA, substitute the base Thymine in the DNA base and bonds with Adenine like as seen in DNA base pairing.
Thus, during DNA duplication, the thymine at the top of the template strand of DNA is replaced with Uracil and binds with Adenine.
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.
I believe the answer is b.
A root of a cotton plant must
overcome various potential forces such as gravitational forces that pulls water
downward, matric forces where there is an adhesion of water molecules from a soil and osmotic forces where attracting water in the presence of large amount of soluble salts in the mixture of soil.
If the soil were compacted by
a heavy vehicle, the matric forces would be mostly affected for compaction will
result to increase matric forces due to reduced size of pores of the soil
making it more difficult to draw water from a solid surface.
Cancer is a mutation that occurs during the cell cycle, usually when it develops and grows it means the mutation was able to go through the cycle undetected at checkpoints so the cell was not destroyed by the lysosomes.
