CELL REPRODUCTION: MITOSISINTERPHASE: DNA replicates

PROPHASE: Chromatin condenses into chromosomes, centrioles start migrating

METAPHASE: chromosomes align in the equatorial plate of the cell

ANAPHASE: sisters chromatids are pulled apart

TELOPHASE: nuclear membrane reforms

CYTOKINESIS: Division of the cytoplasm. The two daughter cells ARE GENETICALLY IDENTICAL TO THE PARENT CELL.

CELL REPRODUCTIONWORKSHOP: MITOSIS

1. Give the correct sequence of the stages of mitosis and say what happens in each. Do a drawing.2. During which stage of mitosis does chromatin coil into chromosomes?3. At which stage or phase the chromosomes line up at the equatorial plate of the cell?4. During which phase sister chromatids pull apart to form single-stranded chromosomes?5. The completion of ____________ marks the end of cell division

CELL REPRODUCTION: MEIOSISInterphase: DNA replicates

Prophase I: Chromosomes are formed. Centrioles migrate. Some DNA sequences are exchanged between chromosomes.

Metaphase I: same as in mitosis, only that chromosomes pairs line up on either side of the equatorial plate.

Anaphase I: Chromosomes are separated. Cromatides DON’T separate.

Telophase I: new nuclear membranes form.

CELL REPRODUCTION: MEIOSISInterphase II: chromosomes DON’T replicate

Prophase II: chromosomes condense, nuclear membrane fragments, centrioles are in opposite sides of the cell.

Metaphase II: chromosomes align in the equatorial plate

Anaphase II: CHROMATIDS separate and begin moving to the poles of the cell.

Telophase II: nuclear membrane forms.

Cytokinesis: Division of the cytoplasm. There are four daughter cells with HALF THE NUMBER OF CHROMOSOMES OF THE INITIAL CELL.

CELL REPRODUCTIONWORKSHOP: MEIOSIS

1. How many divisions undergoes the cell in a meiotic division?

2. Meiosis results in how many cells? And what is their condition?

3. Which cells undergo meiosis?

4. When does the exchange of DNA occur?

5. The name of the cells that are produced by meiosis is…

6. Draw the meiosis division. Use colors and mention the phases the cell is in.

DNA• The nucleus controls, by chromosomes, all the

activities of the cell

• DNA controls the production of proteins within the cell. 

• These proteins, form the structural units of cells and control all chemical processes within the cell.

• Chromosomes are composed of genes, which are segments of DNA that code for a particular protein, which in turn codes for a trait. 

DNA

DNA: deoxyribonucleic acid (DNA), which has a double helix spiral-shaped structure. Each side of the helix has sugar-phosphate molecule.

Nitrogen bases: Adenine (A) pairs with Thymine (T), and Cytosine (C) pairs with Guanine (G).

DNAREPLICATION

Is the process by which DNA makes a copy of itself, and occurs during interphase, before cell division

Replication is semi-conservative, because each strand serves as a base or pattern for the new strand. (Each new DNA has a new strand and an old one)

DNAREPLICATION: STEPS

1. DNA helicase (enzyme) unwinds the DNA. The junction between the unwound part and the open part is called a replication fork.

DNAREPLICATION: STEPS

2. DNA polymerase (a protein) adds the complementary nucleotides and binds the sugars and phosphates. DNA polymerase travels from the 3' to the 5' end of the template strand.

3. One side is the leading strand - it follows the helicase as it unwinds. The other side is the lagging strand - its moving away from the helicase (in the 5' to 3' direction).

DNAREPLICATION

RNA

RNA: ribonucleic acid. It has on strand instead of two, uracil instead of thymine and ribose sugar instead of deoxyribose sugar.

3 types of RNA:•mRNA (messenger RNA•tRNA (transfer RNA)•rRNA (ribosomal RNA)

DNA and RNA

DNA remains in the nucleus… how are then proteins made?

In order for the DNA to get its instructions translated into proteins, it must send its message to the ribosomes, where proteins are made.

DNA and RNATRANSCRIPTION: RNA is made from the DNA. This process occurs in the nucleus.

The mRNA is small and can pass through the nuclear membrane.  It takes the "message" of the DNA to the ribosomes, where it is going to be translated into proteins.

DNA and RNATRANSLATION: occurs in the cytoplasm, specifically on the ribosomes.

The mRNA travels out to the ribosome to carry the "message" of the DNA. At the ribosome, that massage will be translated into an amino acid sequence, which is a protein.

This protein will codify for a specific trait.

GENETIC CODE

Phe: phenilalanineLeu: LeucineIle: IsoleucineMet: MethionineVal: ValineSer: SerinePro: ProlineThr: ThreonineAla: AlanineTyr: TyrosineHis: HistidineGln: GlutamineAsn: AspargineLys: LysineAsp: Aspartic AcidGlu: Glutamic AcidCys: CysteineTrp: TryptophanArg: ArginineGly: Glycine

References

• http://www.cellsalive.com/meiosis.htm• http://www.pbs.org/wgbh/nova/body/how-cells-divide.html• http://www.biologycorner.com/worksheets/DNAcoloring.html• http://www.biologycorner.com/APbiology/DNA/13-

3_replication.html• http://www.biologycorner.com/bio1/DNA.html•