Bacterial genetics

Question 1

INTRODUCTION:

1. discovered DNA
2. discovered nucleotides (building block of DNA)
3. discovered the helical structure of DNA
4. discovered 3D structure of DNA
5. study of genes
6. basic unit of hereditary; carries the info of bacteria
7. all genes taken together within an organism; carries
   the info for cell growth & replication of bacterial cell

Answer 1

1. Fredeick Miescher
2. Phoebus A.T. Levine
3. Rosalind Franklin
4. James Watson & Francis Crick
5. Genetics
6. Gene
7. Genome

Question 2

DNA & RNA MOLECULE:

______: double helical chain of molecules which encodes genetic info
1. nucleotide composition (3)
2. purine
3. pyrimidine

______: single stranded and shorter chain of molecules
1. nucleotide composition (3)
2. purine
3. pyrimidine
4. carries the genetic info from DNA to ribosomes
5. part of ribosomal organelle
6. transfers specific amino acid

Answer 2

DNA
1. phosphate group, deoxyribose sugar, nitrogenous base
2. adenine, guanine
3. cytosine, thymine

RNA
1. phosphate group, ribose sugar, nitrogenous base
2. adenine, guanine
3. cytosine , uracil
4. messenger RNA
5. ribosomal RNA
6. transfer RNA

Question 3

Replication of Genetic Information

1. for enzymes & cofactors to act on DNA molecule
2. DNA polymerase opens the replication fork (Y-
   region where DNA separated)
3. each parent strand serves as template from which complementary strand is produced
4. occurs when 2 replication forks meet

Answer 3

1. Unwinding
2. Unzipping
3. Synthesis of new DNA
4. Termination of Replication

Question 4

______: changes that occur in DNA code resulting in a change in the coded protein or in prevention of its synthesis/ alteration in DNA

1. substance that increases the rate of mutation
2. developed by Bruce Ames, is the standard test
   Genome
3. organism containing the mutation
4. give 3 factors that causes mutation

Answer 4

Mutation

1. Mutagen
2. Ames Test
3. Mutant
4. virus, chemical, uv light

Question 5

Types of Mutation
1. change in a single nucleotide base
2. adding or removing nucleotide bases in DNA sequence
3. mutation that has no effect on the cell
4. mutation that is of benefit to the organism
5. mutation that leads to the production of a non-functional gene
- leads to death of organism

Answer 5

1. BASE MUTATION
2. FRAME-SHIFT MUTATION
3. SILENT MUTATION
4. BENEFICIAL MUTATION
5. HARMFUL MUTATION
   - LETHAL MUTATION

Question 6

______: process in which a new recombinant chromosome, one with a
genotype different from either parent, is formed by combining genetic material from two organisms

1. involves a reciprocal exchange between
   a pair of homologous DNA sequences
2. genetic material is not homologous w chromosome it joins
3. accompanies the replication of genetic material and does not
   depend on sequence homolog

Answer 6

RECOMBINATION

1. General Recombination
2. Specific Recombination
3. General Recombination

Question 7

______: uptake & incorporation of naked DNA (competent) into
bacterial cell

1. cell that able to take up dna
2. example spp

Answer 7

Transformation

1. competent cell
2. Neisseria gonorrhoeae

Question 8

______: transfer of bacterial genes by bacteriophage (virus-infected bacterium that contains DNA/RNA that is surrounded by proteins) from one cell to another

1. phage DNA directs the bacterial cell to produce
   new bacteriophage which will then assemble and replicate and will be released when bacterial cell lyses/destruction to infect other bacteria
2. phage DNA is integrated in the genome of
   bacterial cell which will be replicated w/ the bacterial DNA
   - integrated state
   - phage
3. Ex spp

Answer 8

Transduction

1. lytic pathway
2. lysogenic pathway
   - lysogeny
   - temperate
3. Corynebacterium diptheriae

Question 9

______: transfer of genetic material from donor bacterial strain to
recipient strain

1. Facilitated by
2. Ex spp
3. donor strain
4. recipient strain

Answer 9

Conjugation

1. sex pili
2. E. coli system
3. Fertility factor (+)
4. Fertility factor (-)

Question 10

______: small, circular DNA molecules that can exist independently of
host chromosomes

1. DNA molecule or sequence that has a replication origin and is capable of being replicated

Classification
1. can exist either with or without being integrated into host‘s chromosome
2. have genes for pili and can transfer copies of themselves
3. major role in conjugation; bears genes responsible for cell
attachment & plasmid transfer
4. have genes for enzymes capable of destroying/modifying antibiotics
5. may give them a competitive advantage in
microbial world
6. makes host more pathogenic
7. carry genes that degrade substances

Answer 10

PLASMIDS

1. REPLICON

Classification
1. Episome
2. Conjugative plasmids
3. Fertility factor F factor
4. Resistance factors
5. Col Plasmids
- code bacteriocins
6. Virulence Plasmids
7. Metabolic Plasmids