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Question 1

Term

Answer 1

Definition

Question 2

Bacterial genome

Answer 2

Contains chromosome (must-have), plasmids (extrachromosomal DNA), bacteriophages (virus infecting bacteria), insertion sequences, and transposons.

Question 3

Mutation

Answer 3

Change in the DNA base sequence, occurring spontaneously or under pressure (mutagens: chemicals, X-rays, UV light, viruses).

Question 4

Conditional-lethal mutations

Answer 4

Mutant viability depends on growth conditions(permissiveconditions), e.g., temperature-sensitive mutations used in vaccines.

Question 5

Base substitution mutation

Answer 5

Includes silent (no effect), missense (different amino acid), and nonsense (stop codon).

Question 6

Frame-shift mutation

Answer 6

Insertion or deletion of bases leading to a shifted reading frame and often inactive protein.

Question 7

Transformation

Answer 7

Uptake of naked DNA by a competent recipient cell, which can be natural or artificial (electroporation).

Question 8

Transduction

Answer 8

Transfer of bacterial genes via bacteriophages; types: specialized and generalized transduction.

Question 9

Conjugation

Answer 9

Plasmid transfer between bacteria through direct contact via a pilus, important for spreading antibiotic resistance.

Question 10

Transposons

Answer 10

‘Jumping genes’ that move genes (e.g., antibiotic resistance) within or between DNA elements like plasmids and chromosomes.

Question 11

Specialized transduction

Answer 11

Prophage drags bacterial genome during lytic phase, altering the recipient genome.

Question 12

Generalized transduction

Answer 12

Random bacterial genes packaged into phage capsid and transferred to new bacteria.

Question 13

F+ cell

Answer 13

Bacteria containing a conjugative plasmid (donor).

Question 14

F- cell

Answer 14

Bacteria receiving the plasmid (recipient).

Question 15

Hfr cell

Answer 15

F factor integrates into bacterial chromosome, initiating conjugation.

Question 16

F’ cell

Answer 16

Plasmid integrates into chromosome, then excises with some chromosomal DNA for transfer.

Question 17

Antibiotic resistance genes

Answer 17

Often found in plasmids or transposons, facilitating their spread among bacteria.

Question 18

Natural competence

Answer 18

Bacteria naturally capable of DNA uptake, e.g., Streptococcus pneumoniae, Haemophilus influenzae.

Question 19

Lytic bacteriophage

Answer 19

Infects and lyses host bacterial cell immediately.

Question 20

Temperate bacteriophage

Answer 20

Enters lysogenic phase, coexisting with host until lytic phase is triggered.

Question 21

Lysogenic conversion

Answer 21

Phenotype changes in bacteria due to prophage-encoded functions, e.g., toxin production (diphtheria, cholera).

Question 22

Conjugative plasmid

Answer 22

Encodes all functions for conjugation and moves itself.

Question 23

Mobilizable plasmid

Answer 23

Requires assistance from a conjugative plasmid for movement.

Question 24

Non-transmissible plasmid

Answer 24

Cannot move through conjugation.

Question 25

Transposase

Answer 25

Enzyme enabling the transposition of a transposon.

Question 26

Inverted repeats

Answer 26

Flanking sequences required for transposon movement.