Complete question:
Prophase of meiosis I has some important differences from prophase of mitosis. These differences include: ___________BLANK pair, and _________BLANK occurs.
A: chromatids; condensation
B.,chromosomes; separation
C. homologous chromosomes; crossing over
D. homologous chromatids; separation
Answer:
C. homologous chromosomes; crossing over
Explanation:
Prophase I of meiosis and prophase of mitosis are quite distinct with respect to the events occurring in the cells. Prophase-I of meiosis is a relatively long stage. The Zygotene stage of prophase-I includes the pairing of homologous chromosomes. This pairing is mediated by synaptonemal complex and the process is called synapsis. The paired chromosomes undergo the process of crossing over during the pachytene stage of prophase-I. In crossing over, the non-sister chromatids of the bivalents exchange some genetic material between them. The events of synapsis and crossing over do not occur during prophase of mitosis.
Biotic-the decrease of fish can Make the bear population decrease
abiotic-A rapid change in the temperature can make the bear population decline
