Pumping blood in and out of the heart.
Answer:
Triassic Period (252 to 201 million years ago)
All continents during the Triassic Period were part of a single land mass called Pangaea. This meant that differences between animals or plants found in different areas were minor.
The climate was relatively hot and dry, and much of the land was covered with large deserts. Unlike today, there were no polar ice caps.
It was in this environment that the reptiles known as dinosaurs first evolved. Reptiles tend to flourish in hot climates because their skin is less porous than, for example, mammal skin, so it loses less water in the heat. Reptile kidneys are also better at conserving water.
Explanation:
if u read the passage then u would know it so i prefer going thru passage and reading questions
Answer:
these differentiate as a result of signaling mechanisms. ... The daughter cells divides and after each division it becomes more specialized. When it reaches a mature cell type downstream (for example, becomes a red blood cell) it will no longer divide.
