Swamps or maybe those in the desert. In swamps, the soil is too loose for animals to burrow without it caving in. In deserts, since the climate "rising" its getting to hot and dry for animals to burrow without the sand caving in when an animal walks above it.
Answer:
In oxygenic photosynthesis, the first electron donor is water, creating oxygen as a waste product. In anoxygenic photosynthesis various electron donors are used. Cytochrome b6f and ATP synthase work together to create ATP. This process is called photophosphorylation, which occurs in two different ways.
Explanation:
the answer is 21<span>% oxygen, </span>
There are 7 unifying themes in biology
1.Cell structure and function
2.Reproduction
3.Metabolism
4.Homeostasis
5.Heredity
6.Evolution
7.Interdependence