1. Chapter 8 Table of Contents Section 1 Chromosomes
Cell Reproduction
Table of Contents
Section 1 Chromosomes
Section 2 Cell Division
Section 3 Meiosis

2. Chapter 8 Objectives Section 1 Chromosomes
Describe the structure of a chromosome.
Identify the differences in structure between prokaryotic chromosomes and eukaryotic chromosomes.
Compare the numbers of chromosomes in different species.
Explain the differences between sex chromosomes and autosomes.
Distinguish between diploid and haploid cells.

3. Chapter 8 Chromosome Structure
Section 1 Chromosomes
Chapter 8
Chromosome Structure
Chromosomes are rod-shaped structures made of DNA and protein.
In eukaryotes, DNA wraps around proteins called histones to help maintain the compact structure of chromosomes.

4. Section 1 Chromosomes
Chapter 8
Chromosome Structure

5. Chromosome Structure, continued
Section 1 Chromosomes
Chapter 8
Chromosome Structure, continued
Chromosomes in prokaryotes are simpler in structure than chromosomes in eukaryotes.
Single ring attached to the membrane of the cell…

6. Chapter 8 Chromosome Numbers
Section 1 Chromosomes
Chapter 8
Chromosome Numbers
Each species has a characteristic number of chromosomes in each cell.

7. Chromosome Numbers of Various Organisms
Section 1 Chromosomes
Chapter 8
Chromosome Numbers of Various Organisms

8. Chromosome Numbers, continued
Section 1 Chromosomes
Chapter 8
Chromosome Numbers, continued
Sex Chromosomes and Autosomes
Sex chromosomes are chromosomes that determine the sex of an organism.
All of the other chromosomes in an organism are autosomes.

9. Chromosome Numbers, continued
Section 1 Chromosomes
Chapter 8
Chromosome Numbers, continued
Diploid and Haploid Cells
Cells having two sets of chromosomes are diploid (2n).
Haploid cells (1n) have only one set of chromosomes.

10. Section 1 Chromosomes
Chapter 8
Karyotype

11. Chapter 8 Objectives Section 2 Cell Division
Describe the events of cell division in prokaryotes.
Name the two parts of the cell that are equally divided during cell division in eukaryotes.
Summarize the events of interphase.
Describe the stages of mitosis.
Compare cytokinesis in animal cells with cytokinesis in plant cells.
Explain how cell division is controlled.

12. Cell Division in Prokaryotes
Section 2 Cell Division
Chapter 8
Cell Division in Prokaryotes
Cell division is the process by which cells reproduce themselves.

13. Cell Division in Prokaryotes, continued
Section 2 Cell Division
Chapter 8
Cell Division in Prokaryotes, continued
Binary fission is the process of cell division in prokaryotes.

14. Cell Division in Eukaryotes
Section 2 Cell Division
Chapter 8
Cell Division in Eukaryotes
Cell Cycle
The cell cycle is the repeating set of events in the life of a cell.
The cell cycle consists of first interphase, and then cell division.
Cell division in eukaryotes includes nuclear division, called mitosis, and the division of cytoplasm, called cytokinesis.

15. Cell Division in Eukaryotes, continued
Section 2 Cell Division
Chapter 8
Cell Division in Eukaryotes, continued
Interphase
Interphase consists of growth (G1), DNA replication (S), and preparation for cell division (G2).
G0 phase = cells typically do not divide again
Nerve cells

16. Chapter 8 Stages of Mitosis
Section 2 Cell Division
Chapter 8
Stages of Mitosis
Mitosis is divided into stages: prophase, metaphase, anaphase, and telophase.
Mitosis results in two offspring cells that are genetically identical to the original cell.

17. Section 2 Cell Division
Chapter 8
Stages of Mitosis

18. Section 2 Cell Division
Chapter 8
Cytokinesis
During cytokinesis in animal cells, a cleavage furrow pinches in and eventually separates the dividing cell into two cells.
In plant cells, a cell plate separates the dividing cell into two cells.

19. Control of Cell Division
Section 2 Cell Division
Chapter 8
Control of Cell Division
Cell division in eukaryotes is controlled by many proteins.
Control occurs at three main checkpoints.
DNA damage checkpoints
where cell cycle is arrested momentarily to repair damaged DNA

20. Control of Cell Division, continued
Section 2 Cell Division
Chapter 8
Control of Cell Division, continued
When Control is Lost: Cancer
Cancer may result if cells do not respond to control mechanisms.

21. Chapter 8 Objectives Section 3 Meiosis
Compare the end products of meiosis with those of mitosis.
Summarize the events of meiosis I.
Explain crossing-over and how it contributes to the production of unique individuals.
Summarize the events of meiosis II.
Compare spermatogenesis and oogenesis.
Define sexual reproduction.

22. Formation of Haploid Cells
Section 3 Meiosis
Chapter 8
Formation of Haploid Cells
Meiosis is a process of nuclear division that reduces the number of chromosomes in new cells to half the number in the original cell.
Meiosis produces haploid gametes.

23. Formation of Haploid Cells, continued
Section 3 Meiosis
Chapter 8
Formation of Haploid Cells, continued
Meiosis leads to four haploid cells (gametes) rather than two diploid cells as in mitosis.

24. Section 3 Meiosis
Chapter 8
Meiosis I
Meiosis I includes prophase I, metaphase I, anaphase I, and telophase I.
Crossing-over, which is when portions of homologous chromosomes exchange genetic material, occurs during prophase I and results in genetic recombination.

25. Tetrads and Crossing Over - animation
Section 3 Meiosis
Chapter 8
Tetrads and Crossing-over of Genetic Material
Tetrads and Crossing Over - animation

26. Section 3 Meiosis
Chapter 8
Meiosis II
Meiosis II includes prophase II, metaphase II, anaphase II, and telophase II.
Four new haploid cells result.

27. Section 3 Meiosis
Chapter 8
Stages of Meiosis

28. Meiosis and Mitosis animation
Section 3 Meiosis
Chapter 8
Comparing Meiosis and Mitosis
Meiosis and Mitosis animation

29. Development of Gametes
Section 3 Meiosis
Chapter 8
Development of Gametes
Spermatogenesis is the process by which sperm cells are produced.
Oogenesis is the process that produces mature egg cells.

30. Meiosis in Male and Female Animals
Section 3 Meiosis
Chapter 8
Meiosis in Male and Female Animals

31. Chapter 8 Sexual Reproduction Sexual reproduction
Section 3 Meiosis
Chapter 8
Sexual Reproduction
Sexual reproduction
is the formation of offspring through meiosis it is the union of a sperm and an egg.
Offspring produced by sexual reproduction are genetically different from the parents.

32. QUIZ