Answer:
Natural selection can be described as a phenomenon in which individuals of a population which are better adapted to survive in an environment are favored by nature as compared to the individuals of the population which lack better characteristics to survive in the environment.
Through natural selection, evolution occurs and the allelic frequency changes over a period of time. The process of evolution as well as change in the allelic frequencies does not occur just by a single individual, rather it is a collective effort which takes a lot of time. Hence, we say that natural selection changes the population and not a single individual.
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Answer:</h2>
The scientist started to study relationships among various groups of organisms <u>C. by using genetic analyses</u>.
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Explanation:</h2>
The following features were used to study about the relationships between different groups of organism:
- External morphology
- Similarities in structure
- Genetic analysis
- Chemical composition
The molecular similarities in the structure of RNA, DNA, and proteins help to establish the relationship of relationships between different groups of organisms. This was studied through testing the samples obtained by organisms using genetic analyses.
The body structure ( ovaries, testes, and external genitalia) that make sexual reproduction possible. Secondary spermatocytes
Answer:The secretion of aldosterone is directly stimulated by adrenoglomerulotropin.
Explanation:
Aldosterone plays an important role in the regulation of systemic blood pressure through the absorption of sodium and water. The lipid factor(adrenoglomerulotropin) which is obtained from pineal extracts selectively stimulates secretion of aldosterone.