Answer: D. Extinctions occur at higher rates during times of ecological stress when populations and species are poorly adapted.
The answer is Grassland im 99% positive
A relatively constant internal physical and chemical conditions that organisms maintain.
Natural selection occur to give the best survival chance to the organisms. Hence, they bring about biological evolution through future generations thereby increasing the variety of living things. This survival reflects on their ability to produce more offspring. The offspring must continue to survive by competing with the resources found in nature.
A ) males tend to have higher levels of hemoglobin in their blood
