Mitosis: Understanding the Phases

What happens in the prophase of mitosis?

a) The nuclear envelope dissolves
b) Chromosomes decondense
c) Nucleoli disappear
d) Centrosomes move to opposite poles

Answer:

a) The nuclear envelope dissolves

Prophase marks the beginning of mitosis with the nuclear envelope dissolving and chromosomes coiling. It is an essential phase in cell division where important changes take place to prepare for the division process.

During Prophase, the first phase of mitosis, the nuclear envelope begins to disintegrate into small vesicles, and the chromatin tightly coils to form visible chromosomes. This structural change allows the chromosomes to be easily managed and moved during cell division. As the nuclear envelope disappears, the nucleolus disperses, and the centrosomes move to opposite poles, pulling microtubules along to form the mitotic spindle.

This process is crucial for the successful division of genetic material and ensures that the chromosomes are properly distributed to the daughter cells. Understanding the details of prophase helps us grasp the complexity and precision of mitosis.

What occurs during telophase in mitosis?

a) Chromosomes decondense
b) Nuclear envelopes reform
c) Nucleoli disappear
d) Centrosomes move to opposite poles

Answer:

b) Nuclear envelopes reform

Telophase is the end phase of mitosis where significant changes take place to finalize the cell division process.

During Telophase, the final phase of mitosis, the chromosomes that have been pulled to opposite poles begin to uncoil and form chromatin. This signifies the genetic material is transitioning back to its working form inside newly formed nuclei. A new nuclear envelope is created around each set of chromosomes, and the nucleolus reappears within the nuclear area.

At the conclusion of telophase, the cell essentially has two separate nuclei, setting the stage for the final separation into daughter cells during cytokinesis. Understanding telophase helps us comprehend the final steps of mitosis and the crucial role it plays in ensuring proper cell division.