When you consider the present and/or past environment of Mars, could you find all the requirements for life?

Which would happen if more forests were cut down? a. the nitrogen cycle would be stopped b. nitrogen would be fixed by bacteria more quickly c. the amount of co2 in the atmosphere would increase d. fossil fuels would build up in the soil c the amount of co2 in the atmosphere would increase

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?

Why did adult crab numbers decline in he ecosystem, even though sea stars were still available?