Answer:
What we eat matters. The food choices we make every day have a big effect on the environment. The good news is that even small changes in what we buy and eat can add up to real environmental benefits, including fewer toxic chemicals, reduced global warming emissions, and preservation of our ocean resources.
Explanation:
The answer should be allele(s).
Alleles are alternative forms of genes. For example in eye color, there is brown eye allele that produces brown eyes or blue eye alleles that produces blue eyes.
However, note that there may be dominant or recessive alleles. Dominant alleles are always expressed, meanwhile, recessive allele is only expressed when there is no dominant allele existing.
An example is let say brown eye allele is dominant and blue eye allele is recessive. The eye gene is controlled by 2 alleles. If I had one brown eye allele and 1 blue, my eyes will be brown, because brown eye allele is dominant.
Fish don't have ears we can see but they have ear parts inside their heads. They pick up sounds in water through their bodies.