Nov 4 Flashcards Preview

EEOB 3310 > Nov 4 > Flashcards

Flashcards in Nov 4 Deck (32):
1

TRUE/FALSE
Obligate intracellular mutualistic bacteria can be horizontally transferred between different host species

FALSE

2

TRUE/FALSE
Strict anaerobicity is observed in Bacteroides (gut) and Methylococcus (swamps). Aerobic bacteria are among each of their close relatives. Strict anaerobicity is a homologous trait.

FALSE

3

Which social behavior facilitates reliable transmission of gut microbiota?
a) sexual reproduction
b) trophallaxis
c) grooming

b) trophallaxis

4

What type of horizontal gene transfer employs bacteriophages?
a) conjugation
b) natural competence
c) transduction
d) transformation

c) transduction

5

Who developed 1st generation sequencing?

Fred Sanger

6

What were the 1st genomes sequenced?

RNA and DNA viruses

7

What is the C value of a genome?

amount of DNA in a haploid gamete (pg)

8

What is the relationship btw genome size and species complexity?

positive

9

What are 2 factors that increase genome size?

1) acquisition of non-homologous genes
2) gene duplication

10

What are 2 factors that decrease genome size?

1) loss of DNA segments encoding active genes
2) gene inactivation leads to pseudogenes that are lost by deletion bias

11

Underlying regulation of gene expression
can account for...

phenotypic complexity

12

What do sigma factors do?

regulate transcription of genes

13

How many sigma factors do endosymbionts and bacteria have relatively?

endosymbionts: 1-2
bacteria: >15

14

Viral genomes are
a) linear
b) circular
c) both

c) both

15

TRUE/FALSE
viral genomes can be fragmented

TRUE

16

TRUE/FALSE
viral genomes have overlapping coding sequences

TRUE

17

What percent of bacterial genomes code for proteins?

85-95%

18

In bacterial genomes what is the relationship btw genome size and # protein coding genes?

positive

19

Do bacteria have promoters and activators?

YES

20

TRUE/FALSE
Bacterial do NOT have tRNA or rRNA

false

21

What is a prophage?

Viral genome part of bacterial circular genome

22

Which type of horizontal gene transfer depends on ‘natural competence’ due to DNA used as nitrogen source (food) or ‘messages in a bottle’

transformation

23

Conjugation usually happens
a) within a genus
b) within a species
c) both

b) within a species

24

Transduction usually happens
a) within a genus
b) only within a species
c) both

a) within a genus

25

What is a cost of horizontal gene transfer?

genes from divergent background may reduce
fitness of recipients

26

What are 2 benefits of horizontal gene transfer?

1) increased fitness via selection
2) increased genetic variation

27

What is a chromosomal inversion?

segment of chromosome is reversed end to end

28

What do the perpendicular lines in a synteny plot indicate?

chromosomal inversion

29

What do the perpendicular axes of a synteny plot represent?

bacterial chromosome 1
bacterial chromosome 2

30

What do synteny plots show btw bacterial species overall?

relatedness

31

What is codon usage bias?

when some codons occur and are used more often than others

32

What is the availability of corresponding tRNAs for highly expressed codons?

available