Which of the following features are present at the ecosystem level? a) chemical cycling through the food chain

b) input of solar energy

c) complex interactions between a variety of populations

d) all are features of an ecosystem

e) energy flow that begins at the producer level

Can you guys me with this question , and you! : why do you think the breastbone of a bird is so much larger than the breastbone of a cat?

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.

What is used to keep track of the gamates and possible offsprings combination