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.
Answer:
Answer No 1:
The three ways evolution is determined to have occurred are:
A. Molecular similarities
C. Homologous structures
E. Fossil evidence
Explanation:
Since the theory of evolution became popular, scientists have been looking for similarities and differences among organisms so that they can compare which organisms have a more closer ancestor together as compared to other organisms. Scientists look for molecular similarities, such as the similarities in the proteins and other molecules to depict relations among organisms. Homologous structures is a common term in evolutionary studies in which organisms which are more closely related are known to be more similar. Fossil evidences also help a lot in evolutionary studies.'
Answer No 2:
The correct option is C. the most reproductively successful
Explanation:
Natural selection tends to favour the fittest organism. In evolution, 'the fittest; means the organism which have the ability to survive in an environment and to pass on its characteristics to its offspring. The organism which is more reproductively successful is considered to be more successful.
Answer:
SIMPLE DIFFUSION transport
Explanation:
According to this question, John could smell the fragrance of his newly bought bottle of cologne all the way up the hall before he can even get into his bedroom, where he usually keeps it. However, he realizes when he got to his bedroom that he left the bottle of cologne uncovered.
The fragrance of the cologne that spreads from the bedroom all through the hall is as a result of SIMPLE DIFFUSION, a form of PASSIVE TRANSPORT. Diffusion is a form of passive transport in which molecules/fluids move from a region of high concentration to a region of low concentration until it is evenly spread. This is the case with John's cologne, which spread from the bedroom where the concentration is high to the hall, where it is low.
A single point mutation<span> can change the whole DNA sequence. Changing one purine or pyrimidine may change the amino acid that the nucleotides code for.</span>Point mutations<span> may arise from spontaneous </span>mutations<span> that </span>occur<span> during DNA replication.</span>
Answer:
T
C
G
A
T
A
Explanation:
Thymine pairs with Adenine.
Guanine pairs with Cytosine.
