Help on science??:) i’m just stuck tbh

The earth consists of a variety of different organisms. despite their diversity, however, some similarities on the structural and metabolic levels may be seen. these similarities can be attributed to a. similarities among organisms in their proteins and nucleic acids. b. the ability of organisms to readily adapt to sudden environmental changes. c. similarities in organisms' habitats and niches. d. the ability of all organisms to interbreed and produce new species.

How does buring fossil fuels impact does carbon cycle? what large impact does this have on the envirnment?

How does secondary succession differ from primary succession?