Answer: Genetics and Pressures
Explanation:
For natural selection to occur, a population must have a wide variety of individuals with different traits. For example, natural selection would not influence fish body color if all individuals in a population were exactly the same color. Variation of scale color can help a fish species have a higher chance of survival by confusing predators as to what species they are.
Reproductive strategies represent a set of behavioral, morphological, and physiological adaptations that facilitate access to potential mates, improve the chances of mating and fertilization, and enhance infant survival. Male peacocks have bright, big tail feathers, for example, to attract females. If an organism has a high appeal, this will make them more likely to be able to meet and continue the survival of the species.
Environmental pressures, such as plant death, could influence the survival of herbivorous organisms. Say a small land creature consisted off grass, and an epidemic killed all the grass in their region. They would either die off, or they would evolve to find different types of food. The former could reduce population, while the latter could increase it.
C. They are pulled toward Earth by the force of gravity (and in Physics you would learn that the deceleration speed of gravity is -9.8m/s/s)
Nucleic acids also typically contain phosphorous, and nitrogen plays an important structural role in nucleic and proteins. The proteins, being made up a diverse set of amino acids, have, in addition to carbon, hydrogen, oxygen, and nitrogen, the elements sulfur and selenium.
Living things are made of types of molecules, known as macromolecules.
There are four major classes of biological macromolecules:
carbohydrates
lipids
proteins
nucleic acids
Each of these types of macromolecules performs a wide array of important functions within the cell; a cell cannot perform its role within the body without many different types of these crucial molecules. In combination, these biological macromolecules make up the majority of a cell’s dry mass. (Water molecules make up the majority of a cell’s total mass.) All the molecules both inside and outside of cells are situated in a water-based (i.e., aqueous) environment, and all the reactions of biological systems are occurring in that same environment.