The two strands of a dna molecule are held together by hydrogen bonds between the

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

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

Me what would happen if a plant could carry out photosynthesis, but not respiration? question 1 options: it would have no food. it would have too much water. it would be unable to capture the energy in sunlight. it could make food but not break it down for energy.