I would say "gene", as it is the basic unit of heredity.<span />
The reason is because of the theory "the path of least resistance." The bird is not touching anything else, so it doesn't become our fried birdie dinner.
The genes for sex-linked disorders are found on a sex chromosome, but the genes for other inherited genetic disorders are found on other chromosomes.
The answer is A. Putting the aquarium in the dark means that
the aquatic plants will not be able to photosynthesize. The process of photosynthesis produces oxygen
as a by-product. The oxygen is used by the fishes in respiration and release
carbon dioxide. The carbon dioxide is used by the aquatic plants in photosynthesis.
Good evening Aixa,
An experiment is designed so that you can observe the differences between the experimental group and the control group.
The experimental group is the group of specimens you're exposing to the experiment and the control group is a separate group of specimens that is not being exposed to the experiment, but are also being observed.
-Hope this helps!