Chapter 10Cell Division & Genetics

Chapter 10Cell Division & Genetics

GEE ScienceSummer Remediation

Mr. NashDonnie Bickham Middle School

Room 204

GEE ScienceSummer Remediation

Mr. NashDonnie Bickham Middle School

Room 204

Cellular ReproductionCellular Reproduction Multicellular organisms are composed of two

kinds of cells: Somatic Reproductive

Within these cells matched pairs of chromosomes are called homologous chromosomes or homologues.

Homologues are similar in size and carry the same kinds of genes, but are not identical.

Multicellular organisms are composed of two kinds of cells: Somatic Reproductive

Within these cells matched pairs of chromosomes are called homologous chromosomes or homologues.

Homologues are similar in size and carry the same kinds of genes, but are not identical.

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Somatic CellsSomatic Cells

Contain two sets of chromosomes. Two sets of chromosomes is called:

Diploid (2n) Make up almost all cells in an organism. Of the two sets of chromosomes, one set

comes from the mother and one set from the father.

Contain two sets of chromosomes. Two sets of chromosomes is called:

Diploid (2n) Make up almost all cells in an organism. Of the two sets of chromosomes, one set

comes from the mother and one set from the father.

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Mitosis and the Cell CycleMitosis and the Cell Cycle

Mitosis is the reproduction of somatic cells.

Often called cell division. Results in two diploid (2n) cells.

Mitosis is the reproduction of somatic cells.

Often called cell division. Results in two diploid (2n) cells.

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MitosisMitosis

Some unicellular organisms reproduce asexually by mitosis.

Asexual reproduction by mitosis produces a clone of the parent.

Clones are genetically identical.

Some unicellular organisms reproduce asexually by mitosis.

Asexual reproduction by mitosis produces a clone of the parent.

Clones are genetically identical.

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Cell CycleCell Cycle

The cell cycle is the sequence of stages through which a cell passes between one cell division and the next.

Contains six cycles or phases.

The cell cycle is the sequence of stages through which a cell passes between one cell division and the next.

Contains six cycles or phases.

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Six Phases of the Cell CycleSix Phases of the Cell CycleInterphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

Interphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

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InterphaseInterphase

Most of the cell’s lifetime. DNA at this phase is long strands and

is called chromatin. During the later stage, chromatin is

duplicated in preparation for cell division.

Most of the cell’s lifetime. DNA at this phase is long strands and

is called chromatin. During the later stage, chromatin is

duplicated in preparation for cell division.

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ProphaseProphase

Chromatin condenses and coils to from rod shaped chromosomes.

Each arm of the chromosome is called a chromotid and are attached at the centromere.

Chromatin condenses and coils to from rod shaped chromosomes.

Each arm of the chromosome is called a chromotid and are attached at the centromere.

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MetaphaseMetaphase

The nuclear envelope breaks apart. Spindles are completely formed.

The nuclear envelope breaks apart. Spindles are completely formed.

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AnaphaseAnaphase

Chromotids come apart. Chromotids are pulled by the spindle

to each end of the cell.

Chromotids come apart. Chromotids are pulled by the spindle

to each end of the cell.

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TelophaseTelophase

Last stage of mitosis. Chromosomes uncoil forming

chromatin again. The nuclear envelope reforms.

Last stage of mitosis. Chromosomes uncoil forming

chromatin again. The nuclear envelope reforms.

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CytokinesisCytokinesis

The division of the cytoplasm. A cell plate forms within the cell

dividing it into the two daughter cells. The cell plate becomes part of the

new cell membranes.

The division of the cytoplasm. A cell plate forms within the cell

dividing it into the two daughter cells. The cell plate becomes part of the

new cell membranes.

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Meiosis and Sexual ReproductionMeiosis and Sexual Reproduction

Reproductive cells use Meiosis for cell division.

Each cell will be haploid (n) or have only half the original chromosomes.

Sex cells created by meiosis are called gametes.

Reproductive cells use Meiosis for cell division.

Each cell will be haploid (n) or have only half the original chromosomes.

Sex cells created by meiosis are called gametes.

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MeiosisMeiosis

Prior to meiosis gamete cells go through Interphase similar to somatic cells in mitosis.

Meiosis occurs in two divisions: Meiosis I Meiosis II

Prior to meiosis gamete cells go through Interphase similar to somatic cells in mitosis.

Meiosis occurs in two divisions: Meiosis I Meiosis II

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Meiosis IMeiosis I

Prophase I Chromatin condenses into chromosomes. Homologues pair off.

Same as in mitosis.

Prophase I Chromatin condenses into chromosomes. Homologues pair off.

Same as in mitosis.

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Meiosis IMeiosis I

Metaphase I Spindles form. Nuclear envelope disappears

Same as in mitosis

Metaphase I Spindles form. Nuclear envelope disappears

Same as in mitosis

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Meiosis IMeiosis I

Anaphase I Chromotids are pulled apart and pulled

towards the spindles. Same as in mitosis

Anaphase I Chromotids are pulled apart and pulled

towards the spindles. Same as in mitosis

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Meiosis IMeiosis I

Telophase I Chromotids uncoil back into chromatin.

Same as mitosis

Telophase I Chromotids uncoil back into chromatin.

Same as mitosis

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Meiosis I Meiosis IIMeiosis I Meiosis II

After meiosis I, unlike mitosis, cytokinesis does not occur, but a stage called interkinesis.

During interkinesis the chromatin is not duplicated like during interphase.

After meiosis I, unlike mitosis, cytokinesis does not occur, but a stage called interkinesis.

During interkinesis the chromatin is not duplicated like during interphase.

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Meiosis IIMeiosis II

Follows all of the stages of Meiosis I Prophase II Metaphase II Anaphase II Telophase II

After completing Meiosis II, the gamete goes into Interphase to begin the process again.

Follows all of the stages of Meiosis I Prophase II Metaphase II Anaphase II Telophase II

After completing Meiosis II, the gamete goes into Interphase to begin the process again.

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Genetic ExpressionGenetic Expression

DNA makes up the genes. Genes carry the traits that are

inherited. Genotype:

The gene make up for a particular trait. Phenotype:

The visible expression of a genetic trait.

DNA makes up the genes. Genes carry the traits that are

inherited. Genotype:

The gene make up for a particular trait. Phenotype:

The visible expression of a genetic trait.

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Genetic ExpressionGenetic Expression

If an individual inherits two of the same alleles for a particular trait they are homozygous. This can be either dominant or recessive.

If an individual inherits one dominant allele and one recessive allele, the individual is heterozygous.

If an individual inherits two of the same alleles for a particular trait they are homozygous. This can be either dominant or recessive.

If an individual inherits one dominant allele and one recessive allele, the individual is heterozygous.

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