Question

33. Which of the following requires direct contact between a donor bacterium and a recipient bacterium for transfer of DNA? a. Crossing over b. Mutation c. Transduction d. Conjugation e. Transformation 34. All of the following are true of base substitutions except: a A base substitution may cause no change in the protein encoded by the affected gene b. A base substitution can result in the production of a shortened protein c. Mutations rarely involve base substitutions. d. Base substitutions may be caused by radiation or chemical mutagens e. A base substitution may be beneficial if the affected gene encodes an enzyme with enhanced activity. 35. All of the following are true of insertion and deletion mutationexcept a. Insertion may cause no change in the protein encoded by the affected gene. b. Deletion can result in the production of a shortened protein. c. Insertion and deletion can result in a lethal mutation e. Insertion that cause frameshift mutation will not affected the enzyme encoded by the affected gene 36. Antibiotic resistance can be carried on plasmids and passed from bacterium to bacterium during conjugation. True False 37. Mutations are always harmful to cells. True/ False 38. Horizontal gone transfer in bacteria involves a portion of the cell's DNA being transferred from donor to recipient between cells of the same generation True/False 39. In transformation genes are transferred from one bacterium to another as "naked" DNA in solution. Truel False

Answer 1

Answer 33)

Conjugation

There is required a direct DNA transfee between two bacteria. These bacteria are joined by conjugation bridge.

Answer 34)

mutation are rarely involved base substitutions.

because the mutation generally occurs by the base substitution. All other options are correct.

answer 35)

e is the right answer.

Inserrion that caused frame shift mutation will change the whole nucleotide sequence of the base pairs. That's why the protein sequence is changed. This leads to loss the activity of protein.

Answer 36)

True.

Because antibiotic resistance genes are present on plasmid. The plasmid genes are transferred during conjugation. That's why such gene can be transferred between the donor to recipient bacteria.

answer 37)

False.

some mutations are benefical to cell. The kutations which enhance the activity of protein are benefical to the cell.

Answer 39)

false.

During the transformation, the genes are transferewd via some agents such as protein etc.