B. an ecosystem
An ecosystem contains a community (several species of organisms) and the environment including air, water, and more.
carbon: petroleum, coal
oxygen: ice, water, human body
The answer is -12
Starting with a base of 0 cheetahs:
- 5 are born (0+5=5)
- 15 die (5-15=-10)
- 2 come (-10+2=-8)
- 4 leave (-8-4=-12)
After everything happens, the cheetah population has overall lost 12 cheetahs.
This suggests that the body cavity (coelum) evolved before the lophophore. Protostomes are one of the groups of animals having a true body cavity and are believed to share a common ancestor. They include annelids, mollusks, and arthropods. Lophophore is an organ characteristic of aquatic invertebrates (protostomes) that functions in filter feeding, it consists of a ridge of hollow tentacles bearing cilia, which waft food particles into the mouth.<span />
