3-1: Microbial Genome

Question 1

First step in cell division

Answer 1

DNA replication

Question 2

What part of mRNA is converted into proteins

Answer 2

Open reading frames

Question 3

Nucleotides are comprised of…

Answer 3

Nucleobase (nitrogenous base), deoxyribose, phosphate at 5’

Question 4

Difference btw nucleoside and nucleotide

Answer 4

Nucleosides lack P

Question 5

How are nucleotides connected

Answer 5

Phosphodiester bonds btw 5’ P and 3’ OH

Question 6

What are the four nucleobases of DNA

Answer 6

Adenine, cytosine, guanine, thymine

Question 7

What are the pyrimidines

Answer 7

Cytosine and thymine

Question 8

C/G base pair stronger because…

Answer 8

3 hydrogen bonds

Question 9

Differences between RNA and DNA?

Answer 9

RNA = 2’ OH group on ribose sugar (less chemically stable), thymine replaced by uracil, single stranded

Question 10

How are prokaryotic chromosomes structured

Answer 10

Circular with extensive supercoiling

Question 11

What is the nucleoid

Answer 11

Region of cell containing chromosome (not membrane bound like nucleus)

Question 12

What is an example of a bacterium with two chromosomes

Answer 12

Vibrio cholerae

Question 13

Structure of eukaryotic chromosomes?

Answer 13

Multiple linear chromosomes, larger, less compact genomes (euk microbes most compact)

Question 14

What are genes

Answer 14

Genetic material that encodes functional protein or RNA product

Question 15

Microbial genome makeup?

Answer 15

85-90% protein-coding genes

Question 16

How are genes organized

Answer 16

Functionally related clusters

Question 17

What is an endosymbiont

Answer 17

Can only exist within another cell

Question 18

Who has the smallest genome size?

Answer 18

Endosymbionts, parasites

Question 19

How are genome size and number of genes related

Answer 19

Genome size increase, so does number of genes

Question 20

What is the core genome

Answer 20

Genes present in all members (conserved genes)

Question 21

What is the pan genome

Answer 21

All genes present in any member (includes rare genes)

Question 22

What is synteny

Answer 22

Homologous genes arranged in same order in genomes of closely-related lineages

Question 23

What is a genomic island vs islet

Answer 23

When unique genes of genome found in blocks
Island = large block
Islet = small block

Question 24

What is a prophage

Answer 24

When a bacteriophage integrates into the bacterial genomes, become a part of it

Question 25

What is a cargo gene

Answer 25

Carried by prophage, provide the bacterial host with new genes

Question 26

What is a plasmid

Answer 26

Circular DNA molecules replicated in the cytoplasm that encode “non-essential” genes (only required under certain conditions; e.g. antibiotic resistance genes)