We have shelter and food.
The answer should be the third option "number of protons and neutrons." The atomic mass of a element is equal to the amount of protons, and neutrons added together in that element. So for example if we are trying to find the atomic mass of hydrogen you would add the total amount of protons and neutrons together to find it's mass although it doesn't equal the exact amount of it's mass but it's close.
Hope this helps.
I think the correct answer from the choices listed above is option B. The difference in biodiversity between the tundra and the tropical rain forest would be that warmer temperatures and higher average rainfall in the tropical rainforest allow more things to survive. Hope this answers the question.
I think the correct answer from the choices listed above is option D. Destruction of tundra vegetation will likely result in melting of the permafrost. The tundra ecosystem is extremely sensitive to disturbance with little ability to restore itself. The melting of the permafrost will <span>cause the collapse of ground and loss of soil. </span>