Answer:
sugar
Explanation:
The sides of the stepping stool are made of rotating sugar and phosphate particles. The sugar is deoxyribose. The rungs of the stepping stool are sets of 4 sorts of nitrogen bases. Two of the bases are purines-adenine and guanine.
Answer:
i think its something to do with circle of life or stages of growth
Explanation:
Crossing over occurs at the four-strand stage when two homologous chromosomes, each consisting of a pair of sister chromatids, are paired. Each crossover involves just two of the four strands and generates two recombinant strands.
Hope this helps!
Read the "things that matter'