Either, carbon, hydrogen, nitrogen, oxygen, phosphorus, or sulfur. I would go with carbon because of the photosynthesis and cellular respiration<span />
Natural selection refers to the phenomenon by which the species in a population possessing the tendency to get adapted in a condition enhance in numbers in comparison to those who exhibit fewer adaptation capacities over a number of generations.
In other words, it can be stated as the non-random and differential development of distinct genotypes function to sustain favorable variant and to eradicate less favorable variants. Some of the conditions are required for the process of natural selection to take place.
These are heredity, reproduction, variation in individual characters, and variation in the fitness of organisms among the members of the population. If the conditions are met, then the phenomenon of natural selection occurs by default.
The correct option is C.
The heart is part of the cardiovascular system. The heart pump the blood round the body several times in a day. The blood is made up of several types of cells which carry out specific function in the body, these include the white blood cells which serves as soldiers of the body. The lymph refers to the fluid that circulate throughout the lymphatic system. Both the blood and the lymph are carried round the body by the cardiovascular system during the process of circulation.<span />
