The earth's atmosphere contains certain chemicals that absorb infrared energy emitted by the sun and earth. the process by which these chemicals absorb infrared energy is known as the carbon cycle or greenhouse effect or nitrogen cycle and is responsible for insulating or cooling the planet.

What organ is the first to receive nutrients that have been absorbed from the digestive tract?

Grasses--> mice--> cats--> coyotes suppose 10,000 units of energy are available at the level of the grasses. what is the total number of energy units lost by the time energy reaches the coyote?

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.