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Study Guide for third partial

1. Describe the processes of DNA replication and protein synthesis and know its importance in cellular function.

DNA replication- sepç´
arate chromosomes and use each strand to make a complementary strand, you end up with 1 chromosome made up of 2 sister chromatids.
+used before nuclear division

Protein Synthesis- [gene tells how to make protein]1. Transcription- {happens in nucleus} Separate only gene and then copy it with mRNA.
2. Translation- {leave nucleus into ribosome} Translate the message on mRNA into protein with the help of tRNA.

2. Describe the relationship between DNA, genes and chromosomes.
Chromosomes are made up of genes and both are made upof DNA.

3. Name the stages of the cell cycle, and explain what happens during each stage.

* G1 is the interval of growth before DNA replication. The cell's chromosomes are unduplicated during this stage.
* S is the time of synthesis. The name refers to DNA synthesis, because the cell copies its DNA during this stage.
* G2 is the interval after DNA replication and beforemitosis. The cell prepares to divide during this phase.
* The nucleus divides during mitosis.
* At the end of mitosis, the cytoplasm typically divides, and the cycle begins anew in interphase for each descendant cell.

4. Summarize the major events that occur during each phase of mitosis.

Mitosis- one division

+DNA REPLICATION

Prophase- Nuclear member disappearsCentrioles move to opposite poles
Spindle formation begins

Metaphase- Chromosomes line up in center
Spindle attach to centromeres

Anaphase- Sister Chromatids are pulled apart

Telophase- Nuclear membrane forms around each set of chromosomes
Cytokinesis [division of cytoplasm] is completed

5. Summarize the process of meiosis.

Meiosis- two divisions [difference:homologous chromosomes pair up]
+DNA REPLICATION
Pairing of chromosomes: Synapse
Four chromatids together: tetrad
Pairing of chromosomes: Synapse
Four chromatids together: tetrad

Prophase I - Nuclear member disappears
Centrioles move to opposite poles
Spindle formation begins
Crossing over ( mixing of genes)

Metaphase I - Homologous pair line up in the center
Spindles attach tocentromeres.

Anaphase I - Homologous chromosomes are pulled apart

Telophase I - New nuclear member forms
Cytokinesis is completed

Prophase II- Nuclear member disappears
Centrioles move to opposite poles
Spindle formation begins

Metaphase II- Chromosomes line up in center
Spindle attach to centromeres

Anaphase II- Sister Chromatids are pulled apartTelophase II- Nuclear membrane forms around each set of chromosomes
Cytokinesis [division of cytoplasm] is completed
NOT genetically identical
6. Explain how chromosomes assortment and crossing over during meiosis contributes to genetic variation.
Because when the chromosomes mix up the genes, this makes that no duplicated cell is identically equal to the original one.

7. Compareand contrast mitosis and meiosis.

8. Know Mendel’s principles of segregation and independent assortment.
Law of segregation:
* Each individual has two factors (genes) for each trait
* The factors (genes) segregate (separate) during the formation of gametes
* Each gamete contains only one factor (gene) from each pair of factors
* Fertilization gives each newindividual two factors (genes) for each trait

Law of independent assortment: Each pair of factors assorts independently (without regard to how the others separate) All possible combinations of factors can occur in the gametes.

9. Know the difference between genotype and phenotype
Phenotype: physical appearance of the individual with regard to a trait
Genotype: Alleles responsible...