Answer:
Frequency of the allele "r"causing the disease on Tristan da Cunha
%
Frequency of the allele "r"causing the disease in the original population of 15 colonists
%
Explanation:
Frequency of the allele "r"causing the disease on Tristan da Cunha
Given -
Out of 240 descendants on the island, 4 had retinitis pigmentosa (rr).
As per Hardy Weinberg's equllibrium equation
The frequecy of recessive individual in a given population is represented by 
And q represents the frequency of allele r
So, in this case q is equal to

%
Frequency of the allele "r"causing the disease in the original population of 15 colonists
As it is given in the question statement , the frequency of allele "r"causing the disease in the original population of 15 colonists is ten times the frequency of the allele "r"causing the disease on Tristan da Cunha
i.e

%
A. Scientific ideas are changed when better ones are found.
Answer: B) Predator/prey
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Explanation:
The lynx is the predator that hunts and eats the snowshoe hare, which is the prey.
The graph shows that when the hare population is large, so is the predator population because they rely on the hares as a source of food. However, the more predators there are, the less prey there will be. This causes the prey population to decrease. In turn, this decrease causes the predator population to decrease as well. If there's less food, then some of the lynx population will starve to death.
At some point, the hare population will rebound and go back up due to less predators eating them. They have a better chance to survive. As the hare population goes up, so does the lynx population. They're both strongly linked together, and we have this cyclic pattern the graph indicates. You could say this is "the cycle of life" or "cycle of nature" so to speak.
This is a very simplistic viewpoint because it does not account for other factors such as other predators and other prey, and it also doesn't take account of things like habitat loss for instance. Despite that, such predator-prey models are still useful to understand the connection between the two species.
Chemical change because a chemical change is any change that results in the formation of new chemical substances.
Animals have four basic types of tissue: nervous, epithelial, muscle, and connective.