Goats and sheep belong to the same family but different genera. While they often live together in the same pastures, the hybrid offspring that are occasionally produced between the two species rarely survive. When such a hybrid does survive, it is usually sterile. Which of the following best explains the mechanism that maintains reproductive isolation between goats and sheep? a. Gene flow is prevented because the two species belong to different trophic levels and therefore do not share a food source.
b. Habitat isolation creates a prezygotic barrier between the two species.
c. The males of one species and the females of the other species are fertile at different times.
d. The two species have a different number of chromosomes, resulting in a postzygotic barrier.

d. The two species have a different number of chromosomes, resulting in a postzygotic barrier.

Explanation:

The two species i.e. sheep and goat have different number of chromosomes that resulting in a postzygotic barrier. Sheep has 56 number of chromosomes whereas goat has 60 number of chromosomes that causes postzygotic barrier in the offspring produced from the fusion of these two species. Postzygotic barrier leads to the creation of a hybrid that is sterile and unable to produce offspring because of difference in chromosome number.

mountains can affect the climate of nearby lands. in some areas, mountains block rain, so that one side of a mountain range may be rainy and the other side may be a desert. much of airborne moisture falls as rain on the windward side of mountains.

explanation:

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."