Answer:
b. by increasing the heart rate
c. by increasing the respiratory rate
Explanation:
Increased activity of skeletal muscles would require an increased supply of oxygen to these cells to sustain the muscle contraction. Muscle cells perform aerobic cellular respiration in the presence of oxygen and produce ATP molecules to be used during muscle contraction. Therefore, there is an increase in heart rate to pump sufficient blood to the skeletal muscles which in turn ensures enough supply of oxygen. Also, there will be an increase in the respiration rate to inhale the required oxygen.
The third one and the last one.
Genetic Variation
Natural selection results in organisms that are better suited to their environment are able to pass on genes to create strong offspring
Adaptation is the tendency of some members of a population to be better able to survive and reproduce and pass on their characteristics.
