What's the primary reason that mammals and avian dinosaurs thrived in the paleogene period? a. plants developed as the main food source for these heterotrophic organisms. b. their predators had been killed off by the permian extinction. c. their predators had been killed off by the cretaceous-paleogene extinction. d. the earth significantly warmed, and cold-blooded animals couldn't survive.

The correct answer is option B, that is, their predators had been killed off by the Permian extinction.

Explanation:

The avian dinosaurs and the mammals were small creatures, living under the pump of the dinosaurs that reign the world, however, also were ceasing the further enhancement in the development and the size of these species. At the termination of the Cretaceous era, due to the colliding of an asteroid on the Earth, all the dinosaurs got wiped out from the Earth's surface, with the only remaining one of the species of dinosaurs were the small avian species.  

Due to the opening of lots of niches, the avian dinosaurs and the mammals briskly began to diversify, evolve, and become much bigger in size. The mammals won the race for supremacy and they became the most prevailing species on the Earth.  

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."    

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.