Sickle cell anemia is a disease in which red blood cells become irregularly shaped. The disease is caused by the presence of an incorrect amino acid in a certain protein. The disease most likely occurred due to an altered sequence of nitrogenous bases in the-

A. original DNA in the nucleus
B. transcribed mRNA strand
C. tRNA on the ribosome
D. complementary DNA strands

Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds that eat butterflies and moths, yet birds rarely eat the monarchs. likewise, the monarch caterpillars are brightly striped yellow and white and black, and they also are rarely eaten by birds, although some wasps will attack them and feed them to their young. what can be inferred from these observations? monarchs must threaten and attack birds, but not wasps. monarchs have a way of discouraging bird predation that does not involve hiding. monarchs’ wings are so colorful that most birds must find them difficult to eat. monarchs lay more eggs than other less conspicuous butterflies.