Why is it difficult to breathe at high altitudes?

suppose you found a bone of a mastodon which had 6.25%c14and93.75%n14 how long ago did this animal die

What is the advantage of having a folded inner membrane in the mitochondria?

DNA replication results in two DNA molecules, a) each with one new strand and one original strand. b) one with two new strands and the other with two original strands. c) each with two original strands. d) each with two new strands.

Why is the oceanic white tip a good predator?

Define hypothesis and give an example of one.

Name Producers in the Amazon River.

Janice had been experiencing mild flu-like symptoms before going into premature labor at seven months. The premature baby boy developed complications immediately after birth, running a fever and demonstrating neurologic abnormalities.

What does carrying capacity mean? A. the maximum number of reproducing members in a population B. when growth rate start to decrease C. when growth rate levels off at zero D. when growth rate is at its highest

How does the energy in food become available to organisms?

How do people snorkle underwater without oxygen tank?