Question

the process of mitosis (division of the nucleus) is divided into four stages (prophase, metaphase, anaphase, and telophase). immediately following nuclear division (mitosis), the cell membrane must also divide (cytokinesis). animal cells divide the cytoplasm by constricting the cell membrane in the middle to form a cleavage furrow. plant cells form a cell plate in the center to divide the cytoplasm. at interphase, there is only one cell, but after cytokinesis there are two identical cells.

1. name the 4 mitotic stages.
2. how does cytokinesis occur in an animal cell?
3. how does cytokinesis occur in a plant cell?

during interphase, the genetic material is called chromatin and can not be clearly seen because it isnt tightly coiled. when prophase begins, the dna molecules are progressively shortened and condensed by coiling, to form visible chromosomes. enzymes during prophase break down the nuclear membrane and nucleolus so they are no longer visible. spindle fibers also form in prophase which will attach to the chromosomes. at metaphase, the spindle fibers attach themselves to the centromeres of the chromosomes and align the chromosomes at the equator (middle of the cell). anaphase is the next stage. the spindle fibers shorten and the centromere splits separating the two sister chromatids. during telophase, the chromosomes pairs (chromatids are pulled to opposite poles of the cell. the nuclear envelope and nucleolus reform before the chromosomes uncoil. the spindle fibers disintegrate.

1. genetic material is called during interphase and is / is not clearly visible.
2. what makes the chromosomes become visible during prophase?
3. what is used to help break down the nuclear membrane?
4. besides the nucleus, what else is broken down during prophase?
5. what forms during prophase to later attach and move chromosomes?
6. doubled chromosomes are held together by the.
7. where do chromosomes line up during metaphase?
8. during what stage are sister chromatids separated and moved to opposite ends of the cell?
9. name 4 things that happen during telophase.

Explanation:

For question 29, the text states "During interphase, the genetic material is called chromatin and can NOT be clearly seen". For question 30, it says "When prophase begins, the DNA molecules are progressively shortened and condensed by coiling, to form visible chromosomes". For question 31, "Enzymes during prophase break down the nuclear membrane". For question 32, "Enzymes during prophase break down the nuclear membrane and nucleolus". For question 33, "Spindle fibers also form in prophase which will attach to the chromosomes". For question 34, "the spindle fibers attach themselves to the centromeres of the chromosomes". For question 35, "align the chromosomes at the equator (middle of the cell)". For question 36, "Anaphase is the next stage... sister chromatids... pulled to opposite poles". For question 37, "During telophase... nuclear envelope and nucleolus reform... chromosomes uncoil... spindle fibers disintegrate".

Answer:

1. Chromatin, IS NOT
2. DNA molecules are progressively shortened and condensed by coiling.
3. Enzymes
4. Nucleolus
5. Spindle fibers
6. Centromere
7. At the equator (middle of the cell)
8. Anaphase
9. Nuclear envelope reforms, nucleolus reforms, chromosomes uncoil, spindle fibers disintegrate