<span>On the left, they drain into the renal vein
which in turn drains into the inferior vena cava. By contrast, all the
lumbar veins and hepatic veins usually drain directly into the inferior vena cava.</span>
Answer:
bridge,for,and eye or enclosure
Answer:
Differential reproduction leads to a change in allele frequencies over time. This occurs because of natural selection favoring "successful" individuals that produce more viable offspring.
The sickle-cell allele is maintained in populations exposed to malaria through balancing selection, since heterozygous individuals have protection against the disease.