1. The Cell cycle A form of cellular reproduction

3. What is the cell cycle?
A series of steps showing the formation of 2 cells from a single cell
3 main steps:
1. Interphase (carrying out the cell’s normal activities)
2. Mitosis (division of the nucleus)
3. Cytokinesis (division of cytoplasm)

4. Cell cycle

5. interphase The longest phase of the cell cycle G1 Phase: growth
*As the cell grows larger, it must divide or it may die.

6. Interphase Continued…
S-phase: DNA replicates (synthesis)
G2 phase: growth & prep for cell division; critical checkpoint

7. Mitosis: Nuclear Division
Mitosis is called nuclear division because the steps refer to the contents of the nucleus.
4 steps:
Prophase
Metaphase
Anaphase
Telophase

8. Present during interphase Carries genetic info
Chromatin
Present during interphase
Carries genetic info
Looks like noodles – condenses to form chromosomes
Chromosome
Present during mitosis
Carries genetic info
Coiled up so that it looks like an “X”
Chromatid
Present during mitosis
Carries genetic info
½ a chromosome (pulls apart during Anaphase)
*All are made of DNA

9. Vocabulary Chromatin – Chromosome – Chromatid –
loose combo of DNA and proteins (condenses to form chromosomes)
Chromosome –
continuous thread of DNA consisting of numerous genes and regulatory info (X shape)
Chromatid –
one half of the chromosome

10. Vocabulary continued…
Centromere –
Where spindle fibers attach (center)
Telomere –
Found at the tips of the chromosome - helps prevent loss of genes by not allowing chromosomes to attach to each other.
Centrioles –
Small cylinder shaped organelles made of protein tubes. Aids in mitosis.

11. prophase Nuclear membrane disintegrates Nucleolus disappears
Chromatin condenses to form chromosomes
Spindle fibers begin to form at poles

12. metaphase
Chromosomes attach to spindle fibers and line up along the middle of the cell
*Middle

13. anaphase Chromatid pairs separate and move in opposite directions
*Away
Chromatid pairs separate and move in opposite directions
Spindle fibers contract pulling them toward the poles (away from each other)

14. Telophase (Nuclear Division)
Cell begins to separate
Separate nuclei begin to appear
Spindle fibers disappear

15. Cytokinesis (Cytoplasm Division)
The process that results in 2 genetically identical daughter cells
Plant cells form a cell plate in addition to daughter cells dividing

16. question
If a cell containing 46 chromosomes undergoes mitosis, how many chromosomes does each of its daughter cells contain? 46

17. National Geographic Article