The answer to this would be d. :)
Relaxin
<span>Relaxin, secreted by the corpus luteum of the ovary as well as the placenta, is responsible for helping to inhibit uterine activity and to soften the cervix and the collagen in joints. Softening of the cervix allows for dilatation at birth; softening of collagen allows for laxness in the lower spine and so helps enlarge the birth canal. The effect of estrogen is to cause breast and uterine enlargement. Progesterone has a major role in maintaining the endometrium, inhibiting uterine contractility, and aiding in the development of the breasts for lactation. Human placental lactogen (hPL), also known as human chorionic somatomammotropin, serves as an antagonist to insulin, making insulin less effective, thereby allowing more glucose to become available for fetal growth.</span>
Under ideal conditions, populations can grow exponentially. The growth rate increases as the population gets larger. Most populations do not live under ideal conditions and grow logistically instead. Density-dependent factors slow population growth as population size nears the carrying capacity.
According to Charles Darwin's theory of Evolution by natural selection, organisms that possess heritable traits that enable them to better adapt to their environment compared with other members of their species will be more likely to survive, reproduce, and pass more of their genes on to the next generation.
(n.d.). Retrieved from http://www.nas.edu/evolution/Definitions.html
One word answer:Adaptation:
Your answer is C.) The hydrogen bond between complementary nucleotides
Those rectangles are nucleotides, and the nucleotides are held together by hydrogen bonds.
Hope this helps!