Cell growth, function, and reproduction

*The

Cell

Cycle

*Why do cells divide?

*cell size demonstration

*Eukaryotic Cell Cycle

*the processes by which a cell grows, functions, and divides

*Division occurs in order to:*control cell size

*repair damaged cells

*replace old cells

*Eu

kary

otic

Cell

Cycle

*Majority of cell cycle: Interphase*3 stages:*G1 (GAP)Cell growth*S phase(Synthesis) DNA is replicated*G2 (GAP2) Cell prepares for division*Cyclins

*Chromosomes

http://micro.magnet.fsu.edu/cells/nucleus/chromatin.html

*A chromosome is a single long strand of DNA. The DNA is packaged by histones (proteins) bound to it.

http://ghr.nlm.nih.gov/handbook/basics/chromosome https://sites.google.com/site/mrsebiology97/cell-reproduction/2-objective-2-juno-activities-chromosomes

*Centromere: a central constricted region called that serves as an attachment point for the machinery of mitosis.

*Interphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

*Prophase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Spindle fibers

Centrioles

*Metaphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

*Machinery of Mitosis

*The chromosomes are pulled apart by the spindle, which is made of microtubules. The spindle fibers are attached to each centromere (which is part of the chromosome), and anchored on the other end to a centrosome (which is the organizing center for the spindle).

*There are 2 centrosomes, one at each end of the spindle. The chromosomes are lined up between the poles of the spindle.

*When the spindle fibers contract, the chromosomes are pulled to the opposing poles.

*Anaphase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

*Telophase

Animal Cell Plant Cell

Photographs from: http://www.bioweb.uncc.edu/biol1110/Stages.htm

Animal Mitosis -- Review

Interphase

                                              

              

Prophase

                                             

               

Metaphase

                                              

              

Anaphase

                                             

               

Telophase

                                              

              

Interphase

                                             

               

Plant Mitosis -- ReviewInterphase

                                                        

    

Prophase

                                                       

     

Metaphase

                                                        

    

Anaphase

                                                       

     

Telophase

                                                        

    

Interphase

                                                       

     

16

*Cell Cycle

*Meiosis

*Differences in Meiosis I

*During Prophase I, _________ chromosomes pair up together ( called _____________).

*The FOUR chromatids together are called a _________.

* Crossing Over

http://www.phschool.com/science/biology_place/labbench/lab3/images/crossovr.gif

http://www.biologyjunction.com/images/modcrossingover.jpg

*Crossing-Over

*During synapsis, some segments of the chromatids that are touching __________ genes.

*A ________is a segment of DNA that codes for a specific protein.

*This exchanging of genes is called _____________-___________.

*Differences in Meiosis I

*During Metaphase I, the _________ line up in the center.

*During Anaphase I, one of each homologous chromosomes moves to a different end of the cell.

http://www.bio.georgiasouthern.edu/bio-home/harvey/lect/images/comparison.gif

http://www.biology.iupui.edu/biocourses/n100/images/meiosis2cropped.jpg

http://www.biology.iupui.edu/biocourses/n100/images/meiosis2cropped.jpg