GENETICS AND GROWTH OF PROKARYOTIC CELLS

Question 1

binary fission

Answer 1

simple form of reproduction seen in prokaryotes.

Question 2

transformation

Answer 2

foreign genetic material into the host genome

Question 3

conjugation

Answer 3

bacterial form of sexual mating. 2 cells form a conjugation bridge that helps transfer genetic material. goes from the donor male (+) to the female (-).

Question 4

transduction

Answer 4

requires a vector (virus that carries genetic material). bacteriophages (viruses that infect bacteria) can infect Bacteria and release trapped DNA

Question 5

transposons

Answer 5

genetic elements that can insert and remove themselves from the genome

Question 6

growth of bacteria

Answer 6

when bacteria is exposed to a new environment, it enters a lag phase where division increases. as they grow exponentially, it causes the log phase. With too much bacteria and not enough resources, it enters the stationary phase (slows reproduction) and finally the death phase.

Question 7

virions

Answer 7

after hijacking a cells machinery, viruses will replicate and produce viral progeny (virions) to infect additional cells

Question 8

positive sense (viruses)

Answer 8

implies a genome that can be directly translated to functional proteins by the ribosomes of the host cell

Question 9

negative sense (viruses)

Answer 9

Negative sense RNA viruses provide a template for synthesis. they must carry a RNA replicase within the virion to ensure that the strand gets synthesized

Question 10

retroviruses

Answer 10

single stranded RNA viruses. The virion contains 2 single stranded RNA and reverse transcriptase which synthesizes DNA from single stranded RNA. It then integrates into the host cell genome and replicates as it were their own DNA.

Question 11

describe the viral life cycle

Answer 11

• Infection: viruses need to bind to specific receptors
• translational and progeny assembly
• progeny release

Question 12

lytic cycle

Answer 12

during a lytic cycle, bacteriophage maximizes the use of the cells machinery with no regards for the survival of the host cell. Once the cell is swollen with new virions, the cell lyses, and other bacteria can be infected. Viruses in this life cycle are called virulent.

Question 13

Lysogenic cells

Answer 13

integrates into the host genome as. provirus or prophage initiating this cycle. More beneficial for the bacterium because its less susceptible to superinfection

Question 14

prions

Answer 14

infectious proteins that cause misfolding of other proteins (usually from a helical structure to b pleated sheet)

Question 15

Viriods

Answer 15

short circular singe stranded RNA that binds to large RNA sequences and silences genes