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cell reproduction
mr.Vandel's 7th grade advanced science class
Question | Answer |
---|---|
what happens during interphase? | During this phase, the cell copies its DNA in preparation for mitosis. |
what is interphase? | a period of growth and development. |
what is mitosis? | is a method of cell division in which a cell divides and produces identical copies of itself. |
what are homologous chromosomes? | are chromosome pairs, one from each parent, that are similar in length, gene position, and centromere location. |
what is the centromere? | where the chromosomes are held. it is also here that the chromatids coil and twist into an X shape. |
what are chromatids? | two copies of chromosomes in the cell. |
what happens during prophase? | the nucleolus and nuclear membrane dissolve. two small structures called centrioles move to opposite ends of the cell where threadlike spindle fibers begin to stretch across the cell. plant cells don't form these fibers. |
what are centrioles made of? | a substance called tubulin. |
what happens during metaphase? | the pairs of chromatids line ip along the center of the cell. the centromere of each pair attach to the two spindle fibers-one from each side of the cell. |
what happens during anaphase? | each centromere divids and the spindle fibers shorten. the chromatids separate and are pulled to opposite ends of the cell. these separated chromatids are now called chromosomes. |
what happens during telophase? | the spindle fibers disappear. the newly formed chromosomes uncoil, and two new nuclei form. |
what is cytokinesis? | once mitosis is completed the cytoplasm splits into a new cell. in plant cells, a cell plate forms in the middle of the cell and becomes the new cell membrane. as it divides a new cell wall forms around each cell. |