The answer to this would be D: physical components of the environment, such as rocks and sand. The word "biotic" mean all the living organisms within an ecosystem such as plants and animals.
Most of the time m (M) means male and f (F) means female.
Answer:
Natural selection can occur by A
Explanation:
Answer:
The circulatory system comprises of blood vessels which help in removing carbon dioxide from the body. The carbon dioxide produced by the cells is collected by the capillaries where the carbon dioxide gets dissolved in the blood. This blood is carried to the heart via the veins. The heart pumps the deoxygenated blood to the lungs where gaseous exchange occurs between the blood capillaries and the alveoli of the lungs. When we exhale, the carbon dioxide is breathed out.
