Chapter 12:  Sexual Reproduction and Meiosis

1.         How is meiosis different from mitosis?

2.         In meiosis, is the parent cell haploid or diploid?

            How many cells will be produced by meiosis?

            Are they haploid or diploid?

3.         What occurs during meiosis I? (homologous pairs of chromosomes are separated)

            What occurs during meiosis II?  (identical chromatids separate)

4.         Be able to draw and label the stages of meiosis.

5.         What is a tetrad?  What is synapsis?  When does it occur?

            What is crossing over?  Are homologues identical after crossing over?

Chapter 13:  Patterns of Inheritance

1.         Who was the “Father of Genetics”?  When was he born? (1822)

            When was his work recognized (1900-after his death)

            On what organism did he conduct his experiments?

2.         What is dominant?  What is recessive?

            What is the F₁ generation?  F₂ generation?

3.         What is the Principle of Segregation?   What is an allele?

4.         How did Mendel demonstrate the Principle of Segregation?

            What was the dominant phenotype of this experiment?

            What was the recessive phenotype of this experiment?

            What was the phenotype of the F₁ generation?

            What was the phenotype of the F₂ generation? (what ratio?)

5.         What does homozygous mean? 

            What does heterozygous mean?

            What does genotype mean?

            What does phenotype mean?

6.         Be able to make a Punnett’s square (and interprete it) for

            both single gene crosses and double gene crosses.

7.         What is a testcross? 

            Why is it performed with an organism that shows the recessive phenotype?

8.         What is the Principle of Independent Assortment?  How did Mendel demonstrate it?

Chapter 14:  DNA and the Genetic Material

1.         Describe Frederick Griffith’s experiment.

            (Mix dead virulent  Streptococcus pneumoniae with living avirulent S. pneumoniae and will get

            living virulent      S. pneumoniae).

            Avery demonstrated that ______ was transferred from the dead bacteria to the living bacteria?              (DNA)

            What is this process called (transformation)

2.         Luria and Delbruck demonstrated that bacteriophage are composed of which two types of

            biochemicals?

3.         Describe the Hershey-Chase experiments.

            (Grew bacteriophage in radiolabelled media so that either the sulfurs of the proteins were

            labelled or the phosphates of the DNA were labelled.  Demonstrated that the DNA enters the

            bacterial cell so it must carry the genetic information)

4.         What did Erwin Chargaff demonstrate about the relative

            proportions of purines and pyrimidines in DNA?  (That it varies from species to species and that

            adenine and thymine are always present in the same proportion as are guanine and thymine).

5.         Who hypothesized the structure of DNA?

            Did they do any experiments?

            What is the shape of DNA? 

            How many strands (backbones) does it have?

6.         Be able to draw a cartoon of DNA with the following components labeled:

            a. alternating deoxyribose-phosphate backbone

            b. antiparallel nature of the two strands

            c. that the nitrogenous bases extend off of the deoxyribose

            d. adenine pairs only with thymine (2 hydrogen bonds)  

            e. guanine pairs only with cytosine (3 hydrogen bonds)

7.         What are the 4 nitrogenous bases of DNA?

            Which 2 are purines (remember pure Ag)

            Which 2 are pyrimidines

8.         Be able to describe what is meant by semiconservative

            replication.

9.         Where does DNA replication begin? (at the origin of replication)

            How many origins of replication to prokaryotes have? (1)

            How many origins of replication do eukaryotes have? (several)

10.       How does replication occur?

            (Hydrogen bonds between complimentary base pairs are broken, the backbones are cut in spots to allow unwinding-then reannealed. DNA polymerase adds new nucleotides to the 3’OH end, they        are lined up opposite their complimentary base on the template.  Bonds are made between the sugars and phosphates on adjacent nucleotides.

11.       What 3 things does the DNA polymerase require?

            (DNA template, RNA primer, free 3’OH end)

12.       What are Okazaki fragments?  How do they fit into DNA replication?

13.       What enzyme “proof-reads”?  How does it proof-read?

Chapter 15:  Genes and How They Work

1.         What hypothesis did Beadle and Tatum get the Nobel Prize for?

            (Single gene-single enzyme)

2.         What is the Central Dogma?

            (DNA transcription>mRNA translation>protein)

3.         How is RNA different from DNA?

4.         How is transcription different from DNA replication?  (produces a single strand; only one strand,

            the sense strand, acts as the template; doesn’t require primers)

5.         What is a codon? 

            How many codons are there? 

            Do they all code for amino acids?

            Does more than one codon code for a single amino acid? (yes)

            Does a codon code for more than one amino acid? (no)

            What do I mean by saying that the genetic code is degenerate?

6.         What are the three kinds of RNA?

            What are their roles in protein synthesis?

7.         Describe the structure of a tRNA.  How does it match the appropriate amino acid to the

            appropriate codon?

8.         What is a ribosome composed of? (2/3’s rRNA and 1/3 protein

            -divided between 2 subunits)  What are the roles of the subunits in translation?  (The smaller

            subunit binds the mRNA, the larger subunit binds the tRNA).

9.         How does translation work?  (Small ribosomal subunit binds the mRNA.  The tRNA with the anticodon that is complimentary to the first codon -AUG- forms complimentary base pairs with that codon.  The tRNA is carrying the amino acid coded for by the codon on the mRNA {fmet is generally the first a.a. in a protein}.  THe next tRNA comes in-it has the anticodon that compliments the next codon-forms complimentary base pairs. 

            This tRNA is carrying the amino acid coded for by the codon

            -the amino acids are adjacent to each other so a peptide bond is formed between them.  The previous tRNA can now leave.  The next     tRNA comes in and so forth untill a stop codon is reached.)

10.       What is a single point mutation?  Are they always bad? (no)

11.  What is a frameshift mutation?        Are they generally bad ? (yes)