All aerobic organisms have mechanisms to take in oxygen and remove carbon dioxide. An organism's need for energy-intensive respiratory and circulatory systems depends on which two factors?

Which best compares habitat and niche? o niche is a place in which organisms live, and habitat is the way in which an organism fits into its habitat.o habitat is a place in which organisms live, and niche is the way in which an organism fits into its habitat.habitat is a group of organisms that live in an area, and niche is a specific species that lives in that areao niche is a group of organisms that live in an area, and habitat is a specific species that lives in that area.

Use the drop down menus to match each example to the fossil topic discussed then to show how the fossil record gives evidence of evolution

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy