Answer:
0.4550
Explanation:
In this example, R allele is dominant, so individuals RR and Rr can roll their tongues. If in a population of 1000 gorillas, there are 575 gorillas who can roll their tongues, they will be RR and Rr.
In this case, there is Hardy Weinberg Equilibrium, so the following will be true:

Where:
frequency of RR
frequency of Rr
frequency of rr
The question is what is the frequency of heterozygotes, or, what is the value of 2pq.
We know that RR+Rr is 575 individuals in a population of 1000, or 0.575.
In other words:

So, it is possible to find
:

Now, there are two alleles in the population, so the following will be true:

It is possible to find q (the frequency of allele r) and p (the frequency of allele p):

Therefore:

Now, the frequency of heterozygotes or 2pq is:

Explanation:
Homologous chromosomes are 2 physically different chromosomes that have the same genes but are not genetically identical. Sister chromatids are 2 copies of a single chromosome and so are genetically identical (they also are physically attached to one another).
Answer:
Cancer is caused by changes to certain genes that alter the way our cells function. Some of these genetic changes occur naturally when DNA is replicated during the process of cell division. But others are the result of environmental exposures that damage DNA.
One potential result of climate change is greenhouse effect that is defined as the accumulation of carbon dioxide in the atmosphere that retains heat radiated from the sun. While this can seem beneficial because plants use carbon dioxide in photosynthesis, elevated levels of carbon dioxide actually inhibit photosynthetic mechanisms (Xu, 2015).