1. The Cell Cycle and Protein Synthesis
Chapter 5
The Cell Cycle and Protein Synthesis

3. I. Genes & Chromosomes
1. Genes contain the information needed to build cells and cell products. 2. Genes control thousands of traits.

4. I. Genes & Chromosomes
3. Genes are usually stored in chromosomes. 4. Chromosomes are located in the nucleus. 5. Chromosomes consist of DNA and special proteins.

5. I. Genes & Chromosomes

6. Genes
Specific sections of DNA that code for a specific protein

7. I. Genes & Chromosomes
6. Different living things have various numbers of chromosomes.
a) Humans: 46*
b) Housefly: 12
c) Onion: 16

8. I. Genes & Chromosomes 7. Chromosomes occur in pairs
a) Humans: 23 pairs*
b) Housefly: 6 pairs
c) Onion: 8 pairs

9. I. Genes & Chromosomes
8. Each member of a chromosome pair has the same type of genes.

10. A cell that has pairs of chromosomes
Diploid Cell
A cell that has pairs of chromosomes

11. II. Cell Division
1. Occurs when one cell (parent cell) divides to produce two new cells (daughter cells)

12. II. Cell Division
2. Why would a cell want to divide? a) replace cells * cell death * injury b) growth of organism

13. II. Cell Division 3. The cell cycle contains three stages
a) Interphase

14. 3a) Interphase
Genes are copied
Sister chromatids are formed

15. 3a) Interphase Picture

16. II. Cell Division 3. The cell cycle contains three stages
a) Interphase
b) Mitosis

17. 3b) Mitosis
The equal distribution of the parent cell’s duplicated genes between the two new daughter cells
Consists of four phases

18. Phase 1 – Prophase Nuclear membrane disappears Chromosomes coil up
Sister chromatids appear X- shaped
Spindle forms

19. Prophase Picture

20. Phase 2 – Metaphase
The sister chromatids are lined up at the center of the spindle

21. Metaphase Picture

22. Phase 3 – Anaphase
Each pair of sister chromatids separates into two chromosomes
Daughter chromosomes move to opposite ends of the cell

23. Anaphase Picture

24. Phase 4 – Telophase
Daughter chromosomes reach ends of spindle and begin to uncoil
New nuclear membranes form, resulting in two new nuclei

25. Telophase Picture

26. II. Cell Division 3. The cell cycle contains three stages
a) Interphase
b) Mitosis
c) Cytokinesis

27. 3c) Cytokinesis Parent cell divides into two daughter cells
Each cell gets a nucleus, cytoplasm, and some organelles

28. Cytokinesis Picture

29. II. Cell Division
4. Each daughter cell has genes identical to those in the parent cell 5. Purpose: replaces dead or worn-out cells

30. III. Asexual Reproduction
1. Reproduction by mitotic cell division (eukaryotic)
2. Same genetic information as parent cells
a) Offspring are identical to parent

31. III. Asexual Reproduction
3. Examples
a)Budding
* Seen in yeast
* Can result in long chains of cells

32. III. Asexual Reproduction
3. Examples
b) Regeneration
* Regrowing missing body parts
* Seen in planarian worms

33. III. Asexual Reproduction
3. Examples
c) Spores
* Cell surrounded with a protective covering
* Produced by mitotic cell division
* Each spore can grow into a new organism

34. IV. Sexual Reproduction
1. Occurs when two org. each give one complete copy of their genes to form a new organism a) Organisms will have 2 genders (male and female)

35. IV. Sexual Reproduction
2. Uses the process of meiosis
a) Involves two cell divisions
b) Each daughter cell has just one copy of the genes
* Referred to as gametes

36. A cell that has only one of each chromosome
Haploid Cell
A cell that has only one of each chromosome

37. 2. Meiosis
c) Two types of gametes: * Egg produced by females * Sperm produced by males * The sperm and egg each contribute one member of each pair of chromosomes

38. IV. Sexual Reproduction
3. After meiosis, fertilization occurs
a) Combining of gametes

39. IV. Sexual Reproduction
3. After meiosis, fertilization can occur.
a) Egg and sperm unite to form a diploid cell
* Referred to as a zygote
* Goes through many cycles of mitosis to grow into an adult

40. V. Offspring
1. Asexual reproduction produces offspring identical to parent 2. Sexual reproduction produces offspring similar to, but different from, the parents