According to the theory of natural selection some individuals in a population survive while others die he proposed that survival is due to the

Which statement best describes a keystone species? o a. it has littlelmenetic variation. it has an extremely high population. 0 b. 0 c. it remains unaffected by all environmental changes. od. it has a strong influence on the ecosystem. 0 e. it's the first species to populate a new ecosystem.

Which of the following is a macronutrient? carbohydrates lipids amino acids all of the above

When a person is exercising the body needs to deliver increased amounts of oxygen to the muscles which component of blood ensures that the muscles will receive it