6. Bacterial Genetics and Pathogenicity

Question 1

Gene

Answer 1

A segment of DNA that specifies for a particular polypeptide

Question 2

Codon

Answer 2

a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.

Question 3

Non-sense codon

Answer 3

UAA, UGA and UAG do not code for any amino acid; stop codons. Terminate synthesis of polypeptide.

Question 4

DNA

Answer 4

• 4 nucleic acid bases: purine (Adenine, Guanine) & pyrimidine (Cytosine, Thymine)
• Backbone: deoxyribose phosphate
• strands held together by hydrogen bond

Question 5

RNA

Answer 5

• One chain of nucleotides
• sugar ribose instead deoxyribose
• Uracil instead of thymine

Question 6

Types of RNA

Answer 6

1. Messenger RNA
2. Ribosomal RNA
3. Transfer RNA

Question 7

Messenger RNA (mRNA)

Answer 7

A type of RNA that carries the code or chemical blueprint for a specific protein

Question 8

Ribosomal RNA (rRNA)

Answer 8

A nucleic acid plays a role in transferring information from DNA to the protein-forming system of the cell

Question 9

Transfer RNA (tRNA)

Answer 9

Short-chain RNA that attach the correct amino acid to the protein chain that is being synthesized at the ribosome of the cell.

Question 10

Extra chromosomal genetic elements

Answer 10

1. Plasmid(s)
2. Bacteriophage or prophage
3. Transposon

Question 11

Plasmid

Answer 11

• Circular DNA molecules present in the cytoplasm of the bacteria
• Encode genetic information for many properties

Question 12

Types of plasmids

Answer 12

1. Conjugative plasmids (F plasmids & R plasmids)

2. Non-conjugative plasmids