It is a perfect example of a natural selection.
(I'm not sure if this is the exact answer that you are looking for.)
Answer:
Poverty is the root of all evil in this situation along with gendder discrimination. Because of the social unpopularity regarding females and because many women lie below standard income, they simply cant afford or just refuse to have kids.
Explanation:
Blood vessels visible in the posterior view of the heart include the Superior and inferior vena cava and the pulmonary veins. The superior vena cava and the inferior vena cava drain systemic venous blood into the posterior wall of the right atrium. The pulmonary veins transport blood from the lungs back to the heart and are best seen in posterior view of the heart. Other features visible in the posterior view include, right and left atrium, right and left ventricle, aorta, aortic arch, pulmonary veins and arteries, coronary sinus, coronary artery and posterior interventricular artery.
Three of the four nitrogenous bases that make up RNA — adenine (A), cytosine (C), and guanine (G) — are also found in DNA. In RNA, however, a base called uracil (U) replaces thymine (T) as the complementary nucleotide to adenine (Figure 3). ... (Remember, DNA is almost always in a double-stranded helical form.)
