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

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.

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.

Section 1 Chromosomes Chapter 8 Chromosome Structure

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…

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

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

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.

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.

Section 1 Chromosomes Chapter 8 Karyotype

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.

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

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.

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.

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

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.

Section 2 Cell Division Chapter 8 Stages of Mitosis

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.

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

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.

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.

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.

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.

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.

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

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

Section 3 Meiosis Chapter 8 Stages of Meiosis

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

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.

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

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.

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