Question

1. if you found that two sets of chromosomes (one from species \x\ and one from species \y\) showed a very close match (in the number of chromosomes and many identical banding patterns), it would be most reasonable to say that...

a) one species evolved from the other
b) both species evolved from a common ancestor relatively recently
c) both species may be distantly related
d) their chromosome similarities are only a striking coincidence

Explanation:

Chromosome number and banding patterns are important in evolutionary studies. If two species have very close - matching chromosome numbers and many identical banding patterns, it suggests a relatively recent common ancestry. Option A is too extreme as it implies a direct one - way evolution (which is not well - supported by just chromosome similarity). Option C, being distantly related, would likely show more differences. Option D is unlikely as chromosome similarities are not just coincidences in most cases.

Answer:

B. both species evolved from a common ancestor relatively recently