Biology STAAR review

Cell Cycle, Mitosis, Meiosis

Replication, Transcription and Translation

Cell Cycle

• The cell cycle is divided into two parts:– Interphase– Mitosis (M phase)

Cycle Phase Description

Interphase

G0 Cell is not dividing or growing

G1 phase General growth stage of cell

S phase Replication of DNA (repair DNA if possible)

G2 phase Preparation for Division (creation of Centrioles)

M phase Division of cell

Cell Cycle

• Label the diagram

G1

S

G2

Prophase Metaphase

Anaphase

Telophase & Cytokinesis

Interphase

Spindle FibersCentrioles

Nuclear EnvelopeChromosome

Cell membrane

Nucleus

Centrioles

Chromatin

Daughter Cells

Sister Chromatids

Cell CycleCell Cycles Description

Interphase• Cell grows, replicates DNA and prepares for

division

Prophase• Chromatin condenses into Chromosomes• Nuclear envelope disappears

Metaphase• Chromosomes line up at the middle

(metaphase plate)

Anaphase• Sister chromatids separate and move to

opposite cell poles

Telophase• Chromatids unwind back into chromatin• New nuclear envelope develops

Cytokinesis• Cell divides into 2 new IDENTICAL daughter

cells (cloning)

Meiosis

• Process of cell divisions making gametes (haploid sex cells)

• Homologous chromosomes – matching chromosome sets from mother and father

• Crossing over – happens in Prophase 1 of meiosis, increases genetic diversity of gametes

Meiosis

• Label the diagram

Meiosis 1 Meiosis 2

InterphaseProphase 1

Metaphase 1

Anaphase 1Telophase 1

Prophase 2

Metaphase 2

Anaphase 2

Telophase 2

Cytokinesis Cytokinesis

Replication

• Replication is the process of creating two IDENTICAL copies of a DNA molecule

• Both strands of DNA act as a template to make two identical copies of the original

Replication

• Original DNA opens and each strand acts as a template for the new DNA strands

Replication

• Chargaff’s rules state that:– Adenine pairs with Thymine (A = T)– Guanine pairs with Cytosine (G C)

Fill in the complementary strand of DNA

T A C A A G C C C C T C A G G C G C T T T A A C A C TA T G T T C G G G G A G T C C G C G A A A T T G T G A

• Replication happens during S phase of interphase

Transcription

• Transcription is the process of making a copy of DNA into mRNA

• Transcription takes place in the Nucleus

m

Transcription

• RNA is different than DNA– RNA used the following base pairs A, C, G, U

Fill in the complementary strand of mRNA

T A C A A G C C C C T C A G G C G C T T T A A C A C TA U G U U C G G G G A G U C C G C G A A A U U G U G A

Now box the CODONs

Replication and Transcription Comparison

Replication Transcription

Complementary Strand is DNA is mRNA

Nitrogenous Bases A, C, G, T A, C, G, U

New Complementary Strand Stays in Nucleus Leaves Nucleus

Translation

• Translation is the process of building the Polypeptide (Protein) chain

• Translation takes place on the Ribosome in

the Cytoplasm of the cell

• Polypeptides (Proteins) are made of Amino Acids

Translation

• mRNA’s Codons match to the tRNA’s Anticodons

• The Ribosome connects Amino acids together to make the Protein

TranslationUse the mRNA codon chart to determine the sequence of the Amino Acids

A U G U U C G G G G A G U C C G C G A A A U U G U G A

MET – PHE – GLY – GLU – SER – ALA – LYS – LEU - stop