Answer:
1. hydrogen; 2
2. it means two strands of DNA twisted around each other like a winding staircase
Explanation:
I'm assuming this is a T or F question. The answer is F, because the mitochondria of an animal would produce vitamin D, so the answer is F.
Primary consumers enrich the soil,which help plants to grow and create more food energy for all of us.
Answer:
Genetic variation in species
Explanation:
