Earth is the largest terrestrial planet in the solar system. Earth's huge size enables it to exert enough gravitational force to hold onto its . Mars, which is an inner planet, has a than Earth because of its size.

Lower gravitational force due to lower mass.

Explanation:

Mars has lower gravitational force than Earth because of its lower size because mass has a direct effect on gravitational force of an object. Earth has mass of 5.972 × 10^24 kg which is 10 times greater than mass of Mars which is 6.4171 x 10^23 kg. So due to earth's more mass, it has more gravitational force than planet Mars which has lower mass than earth.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).