Answer:
There needs to be enough sea urchins for otters to come and there needs to be enough otters to eat the urchins.
Explanation:
The heart is beneath the breastbone in the chest cavity of the frog
Answer:
Option B, Mammals and reptiles in the post-dinosaur age.
Explanation:
Adaptive radiation is mechanism through which species evolve very fast from common single ancestors. In simple words two different species are said to have evolved through adaptive radiation when they have descended from a single lineage. This is not the case with mammals and reptiles.
Generally in adaptive radiation, a species evolve when it faces new environmental challenges due to change of habitat or area. For example mammals have evolved from dinosaurs.
Hence, option B is correct
MRNA is the correct answer
