Temperature is a common type of controlled variable. If a temperature is held constant during an experiment, it is controlled. Other examples of controlled variables could be an amount of light, using the same type of glassware, constant humidity, or duration of an experiment
The controlled variable in an experiment could be the amount of water.
Explanation:
The experiment is to see how the amount of water changes the growth of the same plant type. The amount of water is what we are controlling, to see if we get different results from the plant growth.
Answer: Seminal vesicles, Cowper's glands, and the prostate gland
Explanation:
Seminal vesicles make a sugary secretion that nourishes the sperm cells. Cowper's glands and the prostate work together to create secretions that protect the cells.
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.
