Cell Division Mitosis Meiosis Image Cell Division Wikipedia

  • Slides: 23
Download presentation
Cell Division Mitosis & Meiosis Image: Cell Division, Wikipedia From the Virtual Cell Biology

Cell Division Mitosis & Meiosis Image: Cell Division, Wikipedia From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Eukaryotic Cell Cycle Like prokaryotic cell cycle, in that… – Cell grows. – DNA

Eukaryotic Cell Cycle Like prokaryotic cell cycle, in that… – Cell grows. – DNA is replicated. - Mitotic cell division produces daughter cell identical to the parent. Different from prokaryotic cell cycle, in that… – Eukaryotic cells have more DNA on many linear chromosomes. (Q: How many do humans have? ). – The timing of replication and cell division is highly regulated. Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Eukaryotic Cell Cycle 2 major phases: • _____ – DNA replication - Two copies

Eukaryotic Cell Cycle 2 major phases: • _____ – DNA replication - Two copies of each chromosome • ____ (4 stages + cytokinesis) - DNA condensed - Cell divides Image: Cell cycle by Richard Wheeler From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Interphase Non-dividing state With 3 sub-stages: 1. Cell does its job 2. DNA replication

Interphase Non-dividing state With 3 sub-stages: 1. Cell does its job 2. DNA replication 3. Two copies of chromosomes form Image: Cell cycle by Richard Wheeler; Interphase in Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Mitosis Division of body cells (non-reproductive cells) in eukaryotic organisms. A single cell divides

Mitosis Division of body cells (non-reproductive cells) in eukaryotic organisms. A single cell divides into two identical daughter cells. Daughter cells have same # of chromosomes as does parent cell. Images: Cell cycle by Richard Wheeler; Overview of Mitosis, Mysid From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Packing for the move… When cell is not dividing… ● DNA molecules in extended,

Packing for the move… When cell is not dividing… ● DNA molecules in extended, uncondensed form ● Cell can only replicate DNA when in extended state When cell is preparing for division… DNA molecules condense to form chromosomes prior to division. ● – each chromosome is a single molecule of DNA – easier to sort and organize the replicated DNA into daughter cells From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Mitosis 4 sub-phases: 1 st – Prophase 2 nd – Metaphase 3 rd –

Mitosis 4 sub-phases: 1 st – Prophase 2 nd – Metaphase 3 rd – Anaphase 4 th – Telophase followed by Cytokinesis Secret to remembering phases in order… Image: Mitosis diagram, Marek Kultys From the Virtual Cell Biology Classroom on Science. Prof. Online. com

1. Prophase 3 Major Events - chromosomes condense - spindle fibers form: the “strings”

1. Prophase 3 Major Events - chromosomes condense - spindle fibers form: the “strings” that will pull the chromosomes Fluoresced eukaryotic cell. Chromosomes in blue. Mitotic spindle apparatus in green. Images: Prophase drawing, Henry Gray's Anatomy of the Human Body; Prophase Onion Cell Drawing & Photo, Source Unknown, Fluoresced cell, National Institutes of Health From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Prophase chromatin centrioles condensing nucleus chromosomes nucleolus

Prophase chromatin centrioles condensing nucleus chromosomes nucleolus

2. Metaphase • chromosomes align along middle of the cell centriol es chromosomes spindle

2. Metaphase • chromosomes align along middle of the cell centriol es chromosomes spindle fibers Kinetocores not pictured in this illustration. Images: Metaphase drawing, Henry Gray's Anatomy of the Human Body; Metaphase Onion Cell Drawing & Photo, Source Unknown

3. Anaphase • sister chromatids separate (what are chromatids vs. chromosomes? ) • spindle

3. Anaphase • sister chromatids separate (what are chromatids vs. chromosomes? ) • spindle fibers attached to chromosomes pull chromatids towards opposite sides of cell Images: Anaphase drawing, Henry Gray's Anatomy of the Human Body; Anaphase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on Science. Prof. Online. com

4. Telophase • spindle fibers disappear • nuclear membranes form around both groups of

4. Telophase • spindle fibers disappear • nuclear membranes form around both groups of chromosomes • chromosomes change back to their extended state (no longer condensed) Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Telophase Onion Cell Drawing & Photo, Source Unknown From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Cytokinesis – Plant vs. Animal Cell • Plant cells form cell wall between chromosomes

Cytokinesis – Plant vs. Animal Cell • Plant cells form cell wall between chromosomes from the inside to the outside to make two cells • Animal cells “pinch off” cell membrane to make two cells Images: Telophase drawing, Henry Gray's Anatomy of the Human Body; Ciliate dividing, The. Alpha. Wolf; Telophase Onion Cell Photo, Source Unknown From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Stages of Mitosis I P Image: Onion Cell Drawing & Photo, Source Unknown M

Stages of Mitosis I P Image: Onion Cell Drawing & Photo, Source Unknown M A T

How are sex cells formed? Meiosis - A single sex cell divides into four

How are sex cells formed? Meiosis - A single sex cell divides into four unique daughter cells. - Daughter cells have half the # of chromosomes as parent cell, so they are called haploid. Image: Overview of Meiosis, National Institutes of Health From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Genetics Terminology: Ploidy Refers to the number of sets of chromosomes in cells. ●

Genetics Terminology: Ploidy Refers to the number of sets of chromosomes in cells. ● Haploid – one copy of each chromosome – shown with the letter “n” (half the normal number of chromosomes) - sex cells ● Diploid - two copies of each chromosome – designated as “ 2 n” (the normal number of chromosomes – think pairs) - body cells Diploid organisms receive one of each type of chromosome from female parent and one of each type of chromosome from male parent From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Genetics Terminology: Homologues Chromosomes exist in homologous (similar) pairs in diploid (2 n) cells.

Genetics Terminology: Homologues Chromosomes exist in homologous (similar) pairs in diploid (2 n) cells. Exception: Sex chromosomes (X, Y). Other chromosomes, called autosomes, have homologues. From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Human Karyotype • How many homologous pairs? • How many chromosomes? From the Virtual

Human Karyotype • How many homologous pairs? • How many chromosomes? From the Virtual Cell Biology Classroom on Science. Prof. Online. com Image: Karyotype, National Human Genome Research Institute

Sexual reproduction in humans … • At fertilization, 23 chromosomes are donated by each

Sexual reproduction in humans … • At fertilization, 23 chromosomes are donated by each parent. (total = 46 or 23 pairs). - Half are from mom (egg) - Half are from dad (sperm) • Fertilization results in diploid cell. – Diploid cell; 2 n = 46. (n = 23 in humans) – 23 from mom, 23 from dad • Only sex cells are produced through meiosis. Image: Superficial human anatomy, Mikael Häggström& Rainer Zenz; Sperm & egg, Wikipedia From the Virtual Cell Biology Classroom on Science. Prof. Online. com

Meiosis - Sex Cell (Gamete) Formation In meiosis, there are two divisions of the

Meiosis - Sex Cell (Gamete) Formation In meiosis, there are two divisions of the nucleus: meiosis I & meiosis II Image: Overview of Meiosis, National Institutes of Health From the Virtual Cell Biology Classroom on Science. Prof. Online. com

From the Virtual Cell Biology Classroom on Science. Prof. Online. com Image: Meiosis diagram,

From the Virtual Cell Biology Classroom on Science. Prof. Online. com Image: Meiosis diagram, Marek Kultys

Meiosis & Sexual Reproduction Life Cycle Mitosis * From the Virtual Cell Biology Classroom

Meiosis & Sexual Reproduction Life Cycle Mitosis * From the Virtual Cell Biology Classroom on Science. Prof. Online. com * * Image: Animal Life Cycle, Dr. T’s Bio 328 Genetics

Image: Mitosis diagram & Meiosis diagram, Marek Kultys From the Virtual Cell Biology Classroom

Image: Mitosis diagram & Meiosis diagram, Marek Kultys From the Virtual Cell Biology Classroom on Science. Prof. Online. com