Answer:
Option "C" is correct.
Explanation:
The reason is that, form the two experiments it was concluded that both O1 and O2 were recessive, so all these remaining options which says that any or both of them are dominant are incorrect.
Answer: option C) cowpox and smallpox are caused by the same virus
Explanation:
Cowpox is a skin disease that affects cattle. It is caused by an Orthopoxvirus, with lesions occurring principally on the udder and teats of the animals.
Human infection may occur from touching infected cows, and thus giving immunity to smallpox (an acute infection caused by the same poxyvirus, in HUMANS)
So, Jenner's successful use was because cowpox and smallpox are caused by the same virus
Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
Charles Darwin noticed that among the same species there were variations in traits based upon geographical location. These changes may have evolved from climate differences, predator/prey relationships and food sources. This particular experiment was intended to duplicate natural selection by demonstrating the concepts with artificial selection. The result was that over time, new traits could be bred for. Although there may be more than one correct answer here, the best answer is the first; desirable traits can be selected and bred in offspring.
