Answer:
True and The respiratory system is a biological system consisting of specific organs and structures used for gas exchange in animals and plants
Answer:
Black fur is more fit to survive in the environment than other colors of fur.
Explanation:
"Fitness", in terms of natural selection, is an organism's likelihood to survive in a given environment. Assuming that the increase in black fur is significant (Not attributable to pure chance), we can safely assume this is because Black Fur provides a competitive advantage in said environment over other colors of fur. There may be black terrain that allows them to blend into the environment and ovoid predators, or maybe it keeps them warmer if it is located in a cold region, thereby reducing the amount of resources they need to spend to stay warm.
Blood, flowers, bacteria, and skin
It is called blind. a condition in which the participant is not aware if he/she is in the experimental or control group