Answer: Natural selection occurs when one allele (or combination of alleles of different genes) makes an organism more or less fit, that is, able to survive and reproduce in a given environment. If an allele reduces fitness, its frequency will tend to drop from one generation to the next.
Explanation:
Answer:
a
Explanation:
If populations can interbreed, they are considered one species.
Change over time. I believe this is a multiple choice question, but you have not provided the options.
Explanation:
Animals and plants need to get rid of carbon dioxide (c02), this process is called respiration. Respiration happens when the plant/animal breaths in air and releases it as carbon, carbon then moves from fossil fuels to the atmosphere where they are burned. When humans burn fossil fuels to power cities, power plants, cars, and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas.