Presentation on theme: "Chapter 8 Table of Contents Section 1 Chromosomes"— Presentation transcript:
1 Chapter 8 Table of Contents Section 1 Chromosomes Cell ReproductionTable of ContentsSection 1 ChromosomesSection 2 Cell DivisionSection 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 ChromosomesChapter 8Chromosome StructureChromosomes 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.
5 Chromosome Structure, continued Section 1 ChromosomesChapter 8Chromosome Structure, continuedChromosomes 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 ChromosomesChapter 8Chromosome NumbersEach species has a characteristic number of chromosomes in each cell.
7 Chromosome Numbers of Various Organisms Section 1 ChromosomesChapter 8Chromosome Numbers of Various Organisms
8 Chromosome Numbers, continued Section 1 ChromosomesChapter 8Chromosome Numbers, continuedSex Chromosomes and AutosomesSex 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 ChromosomesChapter 8Chromosome Numbers, continuedDiploid and Haploid CellsCells having two sets of chromosomes are diploid (2n).Haploid cells (1n) have only one set of chromosomes.
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 DivisionChapter 8Cell Division in ProkaryotesCell division is the process by which cells reproduce themselves.
13 Cell Division in Prokaryotes, continued Section 2 Cell DivisionChapter 8Cell Division in Prokaryotes, continuedBinary fission is the process of cell division in prokaryotes.
14 Cell Division in Eukaryotes Section 2 Cell DivisionChapter 8Cell Division in EukaryotesCell CycleThe 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 DivisionChapter 8Cell Division in Eukaryotes, continuedInterphaseInterphase consists of growth (G1), DNA replication (S), and preparation for cell division (G2).G0 phase = cells typically do not divide againNerve cells
16 Chapter 8 Stages of Mitosis Section 2 Cell DivisionChapter 8Stages of MitosisMitosis 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 DivisionChapter 8Stages of Mitosis
18 Section 2 Cell DivisionChapter 8CytokinesisDuring 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 DivisionChapter 8Control of Cell DivisionCell division in eukaryotes is controlled by many proteins.Control occurs at three main checkpoints.DNA damage checkpointswhere cell cycle is arrested momentarily to repair damaged DNA
20 Control of Cell Division, continued Section 2 Cell DivisionChapter 8Control of Cell Division, continuedWhen Control is Lost: CancerCancer 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 MeiosisChapter 8Formation of Haploid CellsMeiosis 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 MeiosisChapter 8Formation of Haploid Cells, continuedMeiosis leads to four haploid cells (gametes) rather than two diploid cells as in mitosis.
24 Section 3 MeiosisChapter 8Meiosis IMeiosis 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 MeiosisChapter 8Tetrads and Crossing-over of Genetic MaterialTetrads and Crossing Over - animation
26 Section 3 MeiosisChapter 8Meiosis IIMeiosis II includes prophase II, metaphase II, anaphase II, and telophase II.Four new haploid cells result.
28 Meiosis and Mitosis animation Section 3 MeiosisChapter 8Comparing Meiosis and MitosisMeiosis and Mitosis animation
29 Development of Gametes Section 3 MeiosisChapter 8Development of GametesSpermatogenesis 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 MeiosisChapter 8Meiosis in Male and Female Animals
31 Chapter 8 Sexual Reproduction Sexual reproduction Section 3 MeiosisChapter 8Sexual ReproductionSexual reproductionis 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.