Which statement most accurately describes mutations that are generated in a gene pool?

a. mutations always enhance the phenotype in a gene pool.
b. mutations lead to variation in a gene pool.
c. a gene pool with mutations prevents evolution.
d. a gene pool is unaffected by mutations.

Which of the following is not a characteristic of natural selection? 100 points pls more offspring are born than will survive to reproduce. mutations appear randomly breeding pairs are chosen by humans organisms that are better adapted are more likely to survive

Which of the following describes a negative feedback loop? when the heart rate is too high, the body sends hormones that continually increase the heart rate higher. when a pregnant woman is in labor, the body sends hormones that increase the intensity of contractions, which then increases the secretion of the same hormones. when blood sugar is too low, the body sends hormones that raise blood sugar until it reaches a typical level and hormone secretion slows. when a person is jogging, the body sends hormones that continually decrease the rate of oxygen supply to the legs.

Below, the levels of organization in a multicellular organism are shown from least to most complex. which level of organization can be described as several different types of tissues working together to perform a common task?