Key Terms in Cell Division and Genetics
1. What is cell theory?
- Answer: Cell theory states that:
1. All living organisms are composed of one or more cells.
2. New cells arise only from pre-existing cells through the process of cell division.
2. Define mitosis.
- Answer: Mitosis is a type of cell division in which a daughter cell receives the same number of
chromosomes as the parent cell.
3. What occurs during cytokinesis?
- Answer: Cytokinesis is the process where the cytoplasm of a cell divides, completing the cell division
process.
4. What is interphase?
- Answer: Interphase is the phase between nuclear divisions when a cell grows, doubles its cytoplasmic
content, and replicates its chromosomes.
5. What is chromatin?
- Answer: Chromatin is a complex of DNA and protein found in the nucleus of eukaryotic cells, where
the DNA is not tightly coiled.
6. What role does the centromere play in cell division?
- Answer: The centromere is the structure that holds sister chromatids together until they are
separated during mitosis.
7. How are sister chromatids defined?
, - Answer: Sister chromatids are identical copies of a chromosome, each linked to the other by a
centromere, remaining attached until mitosis occurs.
8. What function do centrioles serve in animal cells?
- Answer: Centrioles are small protein structures found in the cytoplasm of animal cells that play a role
in cell division.
9. What are spindle fibers and their purpose?
- Answer: Spindle fibers are protein structures that assist in guiding chromosomes during the cell
division process.
10. What happens during early prophase?
- Answer: In early prophase, chromosomes become shorter and thicker, centrioles move to opposite
ends of the cell, and spindle fibers begin to form.
11. What occurs in late prophase?
- Answer: During late prophase, chromosomes condense further, centrioles assemble, spindle fibers
attach to the centromeres, and the nuclear membrane begins to dissolve.
12. Describe the metaphase stage of mitosis.
- Answer: In metaphase, chromosomes align at the equatorial plate, and the nuclear membrane
completely disintegrates.
13. What happens during anaphase?
- Answer: During anaphase, the centromeres split, allowing the sister chromatids, now called
chromosomes, to move towards opposite poles of the cell.
14. What is involved in telophase?
- Answer: In telophase, chromosomes lengthen again, spindle fibers dissolve, and a new nuclear
membrane forms around each set of chromosomes, resulting in two nuclei with a total of 46 unique
chromosomes in humans.