Theme 1A

Question 1

Genetics

Answer 1

study of heredity and variation in cells, individuals, & populations

study of genes

Question 2

Gene

Answer 2

functional unit of heredity and variation

DNA sequence involved in making RNA & protein

found on chromosomes & part of the genome that encodes for RNA & protein

Question 3

Molecular Genetics

Answer 3

study of structure and function of genes at the molecular level

Question 4

Allele

Answer 4

variant forms of a gene caused by differences in DNA sequence

Question 5

Genotype

Answer 5

gene(s) inherited by an organism

Question 6

Phenotype

Answer 6

visible traits

Question 7

Genome

Answer 7

entire DNA sequence (ACGT) of an organism

Question 8

Gene Expression

Answer 8

“turning on” a gene to produce RNA & protein (coding gene)

Question 9

RNA can be _________ & __________

Answer 9

coding & noncoding

coding = mRNA - only one that makes protein

non-coding = tRNA & rRNA

Question 10

Gene Expression Diagram

Answer 10

slide 7

Question 11

Protein Expression

Answer 11

the type & abundance of proteins in the cell

Question 12

The protein ultimately determines the phenotype of the cell because…

Answer 12

they control every reaction in the cell

Question 12

Enzymes

Answer 12

proteins catalyzing the synthesis and transformation of all biomolecules

Question 12

Avery, MacLeod, & McCarthy (Classical Experiment)

What was the hypothesis, experimental approach, and conclusion?

Answer 12

Hypothesis: transforming principle could be protein, DNA, or RNA

Experimental Approach: eliminate each type of molecule in S cells and see whether transformation of R cells into S virulent form still occurs

Conclusion: if type of molecule is absent, and transformation is gone, then this molecule is the transforming principle

Question 12

Structure Proteins

Answer 12

maintenance of cell shape

Question 12

Signaling Proteins

Answer 12

hormones and receptors

Question 12

Why is genetics important?

Answer 12

human health
forensics
agriculture
environment
evolutionary biology

Question 13

Griffith - Classical Experiment

Answer 13

found a substance that could genetically transform Streptococcus pneumoniae (pneumonia causing bacteria in mammals)

Conclusion: some molecules (Transforming principle) released when S cells were killed could transform R cells genetically to the virulent S form; transformation was permanent and heritable

Question 13

What are two things responsible for phenotypic variation

Answer 13

Different alleles (variation in gene sequence results in changes in aa sequence of proteins) and differential regulation of gene and protein expression (how much gene is being turned on/off)

Question 13

What are 3 classical experiments that led to estabilishing DNA as a hereditary molecule?

Answer 13

1. Griffith
2. Avery, MacLeod & McCarthy
3. Hershey and Chase

Question 13

Streptococcus pneumoniae

Smooth Strain (S):
Rough Strain (R):

Answer 13

(Griffith) bacterial pathogen causing pneumonia in mammals

S: bacterium surrounded by a polysaccharide capsule - filmy sugary layer; protected by capsule from immune system, which allows for infection, therefore virulent

R: lacks polysaccharide capsule, cannot evade immune system, therefore non-virulent

Question 14

Avery, MacLeod, & McCarthy (Classical Experiment)

What was the experiment?

Answer 14

Enzymes that destroyed RNA (rnase), proteins (protease), and DNA (dnase) were added to cell extract/cytoplasm of heat-killed S cells. If the R cells did not transform into the S virulent form when a molecule was removed, then that molecule was the transforming principle.

• No transformation occurred when DNA was destroyed, making DNA the transforming principle

Question 15

Life Cycle of a Virus (Lytic Cycle)

Answer 15

• massive reproduction of virus resulting in host cell lysis (virulent - harmful to host)
• viral DNA replicated seperately from bacterial chromosome

Question 16

Life Cycle of a Virus (Lysogenic Cycle)

Answer 16

• replication of viral genome (latent)
• viral DNA is integrated into the bacterial chromosome
• life long infection that can only be controlled
• asymptomatic

Question 17

When can lysogeny switch to lytic cycle?

Answer 17

If viral DNA is excised from bacterial chromosome

Question 18

Hershey and Chase (Classical Experiment)

Answer 18

determining if bacteriophage injects DNA or protein into E.coli - label bacteriophage DNA & proteins with radioactive isotope 32P and 35S, respectively - allow infection of E.coli with bacteriphage - separate attached bacteriophage and E.coli with a blender - assay presence of 32P (DNA) and 35S (protein) in detached bacteriophage, E. coli cells, and progeny bacteriophage (done in lytic phase - not shown) Results: - no 35S in E.coli cells & progeny bacteriphage; found in detached bacteriophage; not HERITABLE - 32P found in E.coli cells and progeny bacteriophage; none in detached bacteriophage; HERITABLE

Question 19

Hershey & Chase What would you expect to see if it was done in lysogeny?

Answer 19

not sure