Answer:There may be many possible alleles for any gene, but a diploid cell or animal contains only two alleles of each gene or two copies of a single allele; a haploid gamete contains one copy of each gene, so only one allele.
Explanation:
Answer:
Exposure to the disease
Explanation:
Before vaccines, the only way to develop immunity to a disease was to be exposed to the disease-causing pathogen without being harmed by it. A good example of this is smallpox, which was also the first vaccine developed. It was noticed that milk maids weren't catching and dying from small pox like everyone else, because they had been exposed to cowpox. This premise was used to create the first vaccine.
Vaccines give you immunity by injecting you with a small amount of a (usually inactive) pathogen. inside your body. This means your immune system produces antibodies against it. Similar to what happened with the milkmaids.
Underwater mountain chains called also known as mid-ocean ridges
Answer: C. scorpions have changed as a result of natural selection
Explanation:
The text tells us that scorpions today are now smaller than they were in the past. This means that the scorpions have changed since then i.e. they have evolved.
The primary reason for evolution is natural selection which refers to a situation whereby only the organisms that are better adapted in their species survive.
The conclusion that can be drawn from this research therefore is that we have smaller scorpions today because they stood a better chance of survival than the larger ones and so survived whilst the larger ones died out.