Reproduction. Cell Cycle / Mitosis The cell cycle is the cycle of growth, DNA replication and cell division in eukaryotic cells. The cell cycle is the.

ReproductionReproduction

Cell Cycle / MitosisCell Cycle / Mitosis

• The The cell cyclecell cycle is the cycle of growth, is the cycle of growth, DNA replication and cell division in DNA replication and cell division in eukaryotic cells.eukaryotic cells.

• Cell Cycle AnimationCell Cycle Animation• InterphaseInterphase – Normal cell processes – Normal cell processes

and growth of cell, DNA replication, and growth of cell, DNA replication, and more growth. Cells spend most and more growth. Cells spend most of their time in interphase. of their time in interphase.

MitosisMitosis• MitosisMitosis is the part of the cell cycle where the is the part of the cell cycle where the

replicated DNA (sister chromatids) separates replicated DNA (sister chromatids) separates equally to both sides of the cell. Mitosis produces equally to both sides of the cell. Mitosis produces two identical nuclei within the cell usually in two identical nuclei within the cell usually in preparation for cell division (cytokinesis). preparation for cell division (cytokinesis).

• There are 4 steps to mitosis: There are 4 steps to mitosis: • ProphaseProphase – Nuclear membrane disappears – Nuclear membrane disappears • MetaphaseMetaphase – Sister chromatids line up in the – Sister chromatids line up in the

center of the cell. center of the cell. • AnaphaseAnaphase – Sister chromatids split into – Sister chromatids split into

chromosomes and migrate to opposite sides of chromosomes and migrate to opposite sides of the cell the cell

• TelophaseTelophase – Nuclear membranes form around – Nuclear membranes form around the two sets of chromosomes forming two nuclei.the two sets of chromosomes forming two nuclei.

CytokinesisCytokinesis

• CytokinesisCytokinesis is the part of the cell cycle where is the part of the cell cycle where the cytoplasm and cellular organelles are the cytoplasm and cellular organelles are divided and the cell divides into two separate divided and the cell divides into two separate cells. In animal cells the cell membrane cells. In animal cells the cell membrane pinches in (forms a pinches in (forms a cleavage furrowcleavage furrow) to ) to separate the cells. In plant cells, a separate the cells. In plant cells, a cell platecell plate forms to divide the cell into two separate forms to divide the cell into two separate cells. cells.

Mitosis & Mitosis & CytokinesisCytokinesis Animation Animation

HomeworkHomework• Monday, October 30, 2006Monday, October 30, 2006

6A. Read the section of the textbook6A. Read the section of the textbookWrite the definitions, understand and Write the definitions, understand and memorize the following termsmemorize the following terms

• Asexual ReproductionAsexual ReproductionBinary Fission – not in text. Binary Fission – not in text. BuddingBuddingSporeSporeRegenerationRegenerationSexual ReproductionSexual Reproduction

• Asexual reproductionAsexual reproduction involves only one involves only one parent and produces offspring genetically parent and produces offspring genetically identical to that parent. It is most common in identical to that parent. It is most common in single celled or simple organisms and in single celled or simple organisms and in plants. Asexual reproduction involves plants. Asexual reproduction involves mitosismitosis. .

• Sexual reproductionSexual reproduction involves combining involves combining the genetic material from two parent the genetic material from two parent organisms to produce genetically unique organisms to produce genetically unique offspring. offspring. MeiosisMeiosis is the process by which the is the process by which the gametesgametes are formed in the parents and are formed in the parents and fertilizationfertilization is the process by which a is the process by which a gametegamete from each parent combines to produce the from each parent combines to produce the offspring. offspring.

Asexual Reproduction Asexual Reproduction ExamplesExamples• Binary FissionBinary Fission occurs in bacteria ( occurs in bacteria (prokaryotesprokaryotes) and in most single ) and in most single

celled celled eukaryoteseukaryotes (protists). The cell divides in half to form two (protists). The cell divides in half to form two identical (or almost identical) daughter cells. identical (or almost identical) daughter cells.

• BuddingBudding occurs in eukaryotes (such as yeast) through mitosis (to occurs in eukaryotes (such as yeast) through mitosis (to create two identical nuclei) and the formation of a bud (a small create two identical nuclei) and the formation of a bud (a small protrusion of the cell membrane). The new cell formed is smaller protrusion of the cell membrane). The new cell formed is smaller than the parent cell. Multicellular organisms (such as plants and than the parent cell. Multicellular organisms (such as plants and hydra) also bud to produce offspring genetically identical to the hydra) also bud to produce offspring genetically identical to the parent.parent.

• SporesSpores are specialized cells that act similar to seeds but are are specialized cells that act similar to seeds but are produced asexually. Spores have protective coats that allow them produced asexually. Spores have protective coats that allow them to endure hot, dry, or cold conditions. When conditions are good for to endure hot, dry, or cold conditions. When conditions are good for growth, the spore grows into a new organism genetically identical growth, the spore grows into a new organism genetically identical to the parent. Ferns, bread mold, and mushrooms produce spores. to the parent. Ferns, bread mold, and mushrooms produce spores.

• RegenerationRegeneration occurs through mitotic cell division to reproduce occurs through mitotic cell division to reproduce parts of an organism which are damaged, lost, or injured. Many parts of an organism which are damaged, lost, or injured. Many organisms display varying degrees of regenerative ability. Some organisms display varying degrees of regenerative ability. Some organisms such as planaria and certain starfish can produce organisms such as planaria and certain starfish can produce multiple offspring by regeneration.multiple offspring by regeneration.

BinaryBinaryFissionFission

BuddingBuddingYeastYeast

BuddingBuddingHydraHydra

HomeworkHomework

• Write the definitions, understand and Write the definitions, understand and memorize the following terms (p93, 208, memorize the following terms (p93, 208, 298)298)– GameteGamete– EggEgg– SpermSperm– FertilizationFertilization– ZygoteZygote– HaploidHaploid– DiploidDiploid– Conjugation (Read Page 173)Conjugation (Read Page 173)

BacterialBacterialConjugationConjugation

Sexual ReproductionSexual Reproduction• Gametes are the specialized sex cells formed by Gametes are the specialized sex cells formed by

meiosis in each parent which combine during meiosis in each parent which combine during fertilization to form the offspring.fertilization to form the offspring.

• Egg (Ovum) cells are female gametesEgg (Ovum) cells are female gametes• Sperm cells are male gametesSperm cells are male gametes• Gametes are haploid because they only have one Gametes are haploid because they only have one

copy of each chromosomecopy of each chromosome• Parents are diploid if they have two copies of Parents are diploid if they have two copies of

each chromosomeeach chromosome• Meiosis is the process that makes haploid Meiosis is the process that makes haploid

gametes from diploid cells.gametes from diploid cells.• During fertilization, two haploid gametes combine During fertilization, two haploid gametes combine

to form a diploid zygote.to form a diploid zygote.• A zygote is a fertilized cell – the offspringA zygote is a fertilized cell – the offspring

KaryotypeKaryotype

MeiosisMeiosis

Meiosis IMeiosis I

Meiosis IIMeiosis II

FertilizationFertilization

HomeworkHomework

• Draw and label a color diagram of an Draw and label a color diagram of an eukaryotic eukaryotic cell cyclecell cycle on white unlined paper on white unlined paper with no holes. with no holes. – Include:Include:– InterphaseInterphase– ProphaseProphase– MetaphaseMetaphase– AnaphaseAnaphase– TelophaseTelophase– CytokinesisCytokinesis

• State what happens at each phase. Label the State what happens at each phase. Label the parts that are mitosis.parts that are mitosis.

HomeworkHomework• Draw and label a color diagram of Draw and label a color diagram of meiosismeiosis on white unlined on white unlined

paper with no holes.paper with no holes.– Include:Include:– InterphaseInterphase– Prophase I Prophase I – Metaphase I Metaphase I – Anaphase I Anaphase I – Telophase I Telophase I – Cytokinesis ICytokinesis I– Prophase II Prophase II – Metaphase II Metaphase II – Anaphase II Anaphase II – Telophase II Telophase II – Cytokinesis II Cytokinesis II

• State what happens at each phase.State what happens at each phase.• Due WednesdayDue Wednesday

NYS Core CurriculumNYS Core Curriculum• 2.1a Hereditary information is contained in genes. Genes are 2.1a Hereditary information is contained in genes. Genes are

composed of DNA that makes up the chromosomes of cells.composed of DNA that makes up the chromosomes of cells.

• 2.1b Each gene carries a single unit of information. A single 2.1b Each gene carries a single unit of information. A single inherited trait of an individual can be determined by one pair inherited trait of an individual can be determined by one pair or by many pairs of genes. A human cell contains thousands or by many pairs of genes. A human cell contains thousands of different genes.of different genes.

• 2.1c Each human cell contains a copy of all the genes 2.1c Each human cell contains a copy of all the genes needed to produce a human being.needed to produce a human being.

• 2.1d In asexual reproduction, all the genes come from a 2.1d In asexual reproduction, all the genes come from a single parent. Asexually produced offspring are genetically single parent. Asexually produced offspring are genetically identical to the parent.identical to the parent.

• 2.1e In sexual reproduction typically half of the genes come 2.1e In sexual reproduction typically half of the genes come from each parent. Sexually produced offspring are not from each parent. Sexually produced offspring are not identical to either parent.identical to either parent.

NYS Core CurriculumNYS Core Curriculum• 4.1a Some organisms reproduce asexually. Other organisms 4.1a Some organisms reproduce asexually. Other organisms

reproduce sexually. Some organisms can reproduce both reproduce sexually. Some organisms can reproduce both sexually and asexually.sexually and asexually.

• 4.1b There are many methods of asexual reproduction, 4.1b There are many methods of asexual reproduction, including division of a cell into two cells (binary fission), or including division of a cell into two cells (binary fission), or separation of part of an animal or plant from the parent separation of part of an animal or plant from the parent (budding), resulting in the growth of another individual.(budding), resulting in the growth of another individual.

• 4.1c Methods of sexual reproduction depend upon the 4.1c Methods of sexual reproduction depend upon the species. All methods involve the merging of sex cells species. All methods involve the merging of sex cells (gametes) to begin the development of a new individual. In (gametes) to begin the development of a new individual. In many species, including plants and humans, eggs and sperm many species, including plants and humans, eggs and sperm are produced.are produced.

• 4.1d Fertilization and/or development in organisms may be 4.1d Fertilization and/or development in organisms may be internal or external.internal or external.

NYS Core CurriculumNYS Core Curriculum

• 4.2a The male sex cell is the sperm. The 4.2a The male sex cell is the sperm. The female sex cell is the egg. The fertilization of female sex cell is the egg. The fertilization of an egg by a sperm results in a fertilized egg an egg by a sperm results in a fertilized egg (zygote).(zygote).

• 4.2b In sexual reproduction, sperm and egg 4.2b In sexual reproduction, sperm and egg each carry one-half of the genetic information each carry one-half of the genetic information for the new individual (haploid). Therefore, the for the new individual (haploid). Therefore, the fertilized egg contains genetic information fertilized egg contains genetic information from each parent (diploid).from each parent (diploid).

NYS Core CurriculumNYS Core Curriculum• 4.4a In multicellular organisms, cell division is responsible for 4.4a In multicellular organisms, cell division is responsible for

growth, maintenance, and repair. In some one-celled growth, maintenance, and repair. In some one-celled organisms, cell division is a method of asexual reproduction.organisms, cell division is a method of asexual reproduction.

• 4.4b In one type of cell division (mitosis), chromosomes are 4.4b In one type of cell division (mitosis), chromosomes are duplicated and then separated into two identical and complete duplicated and then separated into two identical and complete sets to be passed to each of the two resulting cells. In this type sets to be passed to each of the two resulting cells. In this type of cell division, the hereditary information is identical in all the of cell division, the hereditary information is identical in all the cells that result.cells that result.

• 4.4c Another type of cell division (meiosis) accounts for the 4.4c Another type of cell division (meiosis) accounts for the production of egg and sperm cells in sexually reproducing production of egg and sperm cells in sexually reproducing organisms. The eggs and sperm resulting from this type of cell organisms. The eggs and sperm resulting from this type of cell division contain one-half of the hereditary information.division contain one-half of the hereditary information.

• 4.4d Cancers are a result of abnormal cell division.4.4d Cancers are a result of abnormal cell division.