The hemochorial placenta:
A. is found in all primates, except prosimians
B. is more efficient than other types of placentae
C. involves the transmission of nutrients and other material in the blood through a single vessel wall
D. all of these
D. all of these
You might also like to view...
Two groups of animals share a portion of the same habitat. These animal groups look similar to one another, but do not interbreed. Using the biological species concept, these animal groups would be considered _________
a. overlapping species b. hybrid species c. separate species d. one species
Modern industrial societies are noted for having disparate access to economic resources and prestige. What type of stratification exists in these societies?
A) egalitarian B) caste C) class D) rank
In a perfectly competitive market, an increase in the market demand will shift the perfectly competitive firm's ________ curve ________.
A) marginal cost; downward B) marginal revenue; downward C) marginal cost; upward D) marginal revenue; upward
In the 1800s, the small population of the island of Martha's Vineyard included many people who were congenitally deaf. Everyone there spoke sign language because so many people had deaf neighbors or relatives. They could trace this trait back to a few of the original settlers on the island, who were deaf and in the same family. What is the most likely explanation, in evolutionary terms, why so many people on the island were deaf?
A. One of the few founders of the population carried the allele for deafness. B. There was a mutation causing the gene for deafness. C. Gene flow onto the island continually brought in genes for deafness from the mainland. D. The foghorns on the island provided a selective advantage to being deaf.