Given that a cell is undergoing meiosis, at the end of meiosis I, its number of chromosomes would be in half. Provided in the question that the cell in G1 has 40 chromosomes, at the end of meiosis I, there will be 20 chromosomes in each daughter cell. And each chromosome has two sister chromatids, then there will be 40 sister chromatids in each daughter cell.
Answer:
they help lower the activation energy of chemical reactions
The answer is actually A. In the zone of saturation
Crossover occurs when two chromosomes, normally two homologous instances of the same chromosome, break and then reconnect but to the different end piece. If they break at the same place or locus in the sequence of base pairs, the result is an exchange of genes, called genetic recombination.
