microbial genetics - ch 7

Question 1

what is genetics?

Answer 1

study of inheritance & inheritable traits as expressed in an organisms genetic material. this includes the physical structure ad function of genetic material, mutations, & transfering of genetic material among orgnaisms

Question 2

what term defined as the entire genetic complement of an organism?

Answer 2

genome

Question 3

what term describes the transfer of genetic information within the same generation?

Answer 3

horizontal gene transfer

Question 4

what type of horizontal gene transfer requires phsical contact between donor and recipent cells?

Answer 4

conjugation

Question 5

what type of horizontal gene transfer involves the transfer of dna via a virus?

Answer 5

transduction

Question 6

what is a recombinant cell?

Answer 6

genetic recombination between donated and recipient DNA that forms new hybrid genomes (new phenotypes)

Question 7

what happens in horizontal gene transfer?

Answer 7

donor cell contributes part of its genome to a recipent cell which then inserts part of a species from the donors DNA into its own chromosome

Question 8

what is vertical gene transfer?

Answer 8

the transmission of genes from parents to offspring

Question 9

what are the 3 types of horizontal gene transfer?

Answer 9

transformation, transduction, & bacterial conjugation

Question 10

what type of horizontal gene transfer does a competent recipient cell take up DNA from the enviroment?

Answer 10

transformation

Question 11

what is the process of bacterial conjugation?

Answer 11

1. sex pilus connects donor F+ to recipient F-
2. cells are drawn together
3. orgin of transfer (enzyme coded by plasmid nicks one strand and transfers to recipient)
4. cells synthesize complementary strands of F plasmid to form double stranded DNA circles.

Question 12

when does a Hfr (high frequency of recombination) cell result?

Answer 12

when an F plasmid integrates into a prokaryotic chromosome

Question 13

define a bacteriophage

Answer 13

a virus that infects bacteria

Question 14

what is the difference between a geneotype and a phenotype?

Answer 14

geneotype- set of genes in a genome
phenotype- physical features & functional traits

Question 15

what is central dolgma

Answer 15

DNA > RNA > protein

Question 16

name the 2 subcategories of transduction

Answer 16

general - random DNA segments
specialized - specifc DNA sequences are transferred

Question 17

what are the steps of the process of transduction?

Answer 17

1. bacteriophage attaches to host & infects genome into cell
2. phage enzyme degrades the cells DNA
3. phage controlls cell functions & directs the cell to synthesize new phage DNA & proteins
4. host cell lyses and releases daughter & transducing phages
5. recipient cell host incorportaes (new) DNA

Question 18

define cell competence

Answer 18

state of increased cell wall & membrane permeability that allows cells to reputake DNA