unit 2 chap 8

Question 1

how are genotype and phenotype connected?

Answer 1

through rna

Question 2

how is the genotype preserved?

Answer 2

replication

Question 3

genotype vs phenotype

Answer 3

genotype - the genetic makeup of an individual
phenotype - observable characteristics of an individual

Question 4

prokaryote genome

Answer 4

• single circular chromosome
• inheritance through vertical and horizontal transmission

Question 5

what is the process of gene expression

Answer 5

dna –> rna –> protein

Question 6

transcription

Answer 6

dna –> rna
uses mrna to go from DNA to rna using rna polymerase

Question 7

translation

Answer 7

rna –> protiens
uses trna to read mrna and bring amino acids to be linked

Question 8

what is the function of rrna

Answer 8

direct the steps of protein synthesis

Question 9

what is the function of the ribosome

Answer 9

where protein synthesis takes place by making peptide bonds with rrna

Question 10

sense vs antisense

Answer 10

sense - dna storage 5’ to 3’
antisense - what mrna transcripts

Question 11

auxotroph

Answer 11

mutant organism that requires a particular nutrient that the normal one doesn’t

Question 12

what are the different effects of mutation?

Answer 12

silent
- it doesn’t affect the
lethal
- kills the host
beneficial
- mutation helps w survival

Question 13

what is mutations caused by chemical or radiation called?

Answer 13

mutagens

Question 14

spontaneous mutation

Answer 14

random mistakes during replication

Question 15

types of base substitution

Answer 15

missense mutation
- non lethal
- amino acid subsitituion
nonsense mutation
- lethal
- premature stop codon forms
frameshift
- lethal
- insertion or deletion of a single base

Question 16

vertical vs horizontal gene transfer

Answer 16

vertical - identical daughter cells
horizontal - new combination of genes(donor DNA may recombine w recipient chromosomal DNA and form new gene)

Question 17

what are the different types of horizontal gene transfer

Answer 17

transformation,
conjugation,
transduction,

Question 18

transformation

Answer 18

• upatake of “naked DNA” form the environment
• requires competence, come naturally competent and others can be artificially competent( by chemical or electrical shock)
• if cell not competent DNA is degraded

Question 19

conjugation

Answer 19

• transfer of dna via cell to cell contact (donor - recipient)
• uses sex pillus
• uses f+ and f- cells
• f+ and f- results in f+
• f- and hfr results in recombinant f- cell(bc f+ factor is at end of chromosome and cant stay connected long enough for it to transfer)

Question 20

transduction

Answer 20

• dna transfer via viral intermediate(phages)(a part of viral replication)
• viral DNA mix w host and when lysis each virus born can have part of host and part of of viral and go insert to other cells
  
  • generalized transduction: any host gene can transfer
  • specialized transduction: only specific genes(ex shiga toxin, diphtheria toxin, cholera toxin)

Question 21

transposition

Answer 21

• transfer of transposons(have a transposase gene that rec inverted repeat sequences and snips it and jumps around)
  2 types
  
  • simplest: insertion sequences: have only transposase
  • complex: have transposase + other genes
• transposons can move from cell to cell via plasmids or viral DNA(transposon can jump to plasmid from chromosome and that’s transferred)

Question 22

recombination

Answer 22

RecA protein - mediates recombination btwn donor and recipient
- occurs at crossbridges
- allows gain of new functions, repair defective/damaged DNA and genes, promotes diversity

Question 23

Frederick Griffith principle

Answer 23

discovered that dead virus dna can still infect live virus

Question 24

plasmids

Answer 24

small extra chormosomal circular segments of dna
- replicate autonomously and contain own origin or replication
- conjugative plasmids are trasferable have f+ factor and have origin for conjugative transfer
- metabolism, virulence and resistance genes on plasmid
- can have artificial plasmid

Question 25

what is the difference btwn hfr and f+ cells

Answer 25

f+ have f+ strain in plasmid
hfr have f+ in chromosomes(comes from recombination btwn chromosomes and plasmid)

Question 26

transposons

Answer 26

mobile genetic elements naturally jump around chromosome
happens every 10^-5 to 10^-7/generation