Answer :Erwin Chargaff a Biochemist
Explanation:
He formulated the base paring of double helix of DNA. He reasoned that since the percentage of four DNA bases are of this proportions in human;
Adenine=30.9% and Thymine =29.4%;
Guanine=19.9% and Cytosine =19.8%
Then, the amount of adenine will always be equal to thymine,
And the amount of Guanine equals to cytosine based on this percentages of distribution.
(Adenine and Guanine are large, molecule of Purines, while thymine and Cytosine are Pyrimidine)
He concluded (although scientist believed, he did not explicitly stated this) that this should be the base paring patterns in DNA molecule. This is the first Chargaff Rule.
His second rule is that the DNA composition, in the relative amount of the four bases Adenine, Thymine, Cytosine and Guanine varies in proportion from one organisms to another. And this is the basis of molecular diversity.
Are there choices to choose from, because that is a very general question?
<span>The correct answer is 'secondary consumer’. This is because the yellowfin tuna eats herbivorous fish (these are primary consumers - they only eat plants, which are producers) and take refuge from predators. This shows they are not tertiary consumers, as tertiary consumers are at the top of the food chain.</span>
The sexual reproduction helps in having more variation among the offsprings. It also makes the offsprings more resistant to genetic diseases.
<h3><u>Explanation</u>:</h3>
Sexual reproduction is the process by which the gametes of the species fused together to form zygote which develops into an offspring. This offspring produced has the gene from both the parents . This genetic setup is not only copied from the parents but they undergo the crossing over and independent assortment which leads to variation among the offspring itself as well as they differ from their parents too.
This variation among the offspring as well as the crossing over helps to eleminate the lethal genes from the genetic pool. Thereby they help to get more resistance among the offsprings from diseases.
