Free living nitrogen fixing takes place as shown in the following;

             TYPE                                                                                       N-FIXING GENERA

A) Cyanobacteria (blue-green algae)                                        i) Bacillus

B) Aerobic                                                                                     ii) Clostridium

C) Facultative                                                                              iii) Anabaena

D) Anaerobic nonphotosynthetic                                            iv) Rhodospirillum

E) Anaerobic photosynthetic                                                     v) Azospirillum

 Which of the following combination of free living nitrogen fixing bacteria is correct?

TLS Online TPP Program

#Question id: 23887

#Unit 13. Methods in Biology

Which of the following sequences in double-stranded DNA is most likely to be recognized as a cutting site for a restriction enzyme? 

TLS Online TPP Program

#Question id: 23888

#Unit 13. Methods in Biology

A recessive allele usually results from a mutation that

a. disrupts expression of the gene.

b. alters the structure of the encoded protein leading to gain of function.

c. alters the structure of the encoded protein leading to loss of function.

d. increases the activity of the encoded protein.

TLS Online TPP Program

#Question id: 23889

#Unit 13. Methods in Biology

Temperature-sensitive mutations would be particularly useful for studying which of the following processes?

a. DNA synthesis

b. hormone secretion

c. protein synthesis

d. Mitosis

TLS Online TPP Program

#Question id: 23890

#Unit 13. Methods in Biology

Which of the following is an essential element of plasmids used as cloning vectors?

a. a centromere

b. a telomere

c. an origin of replication

d. a drug resistance gene

TLS Online TPP Program

#Question id: 23891

#Unit 13. Methods in Biology

Which of the following is (are) used both in the polymerase chain reaction (PCR) and in DNA sequencing?

a. single-stranded DNA primers

b. deoxynucleotide triphosphates (dNTPs)

c. dideoxynucleotide triphosphates (ddNTPs)

d. DNA polymerase

TLS Online TPP Program

#Question id: 23892

#Unit 13. Methods in Biology

The restriction enzyme BglIl has the recognition sequence (A*GATCT) and cuts between the A and the G as indicated by the asterisk. DNA cut by which of the following restriction enzymes (given with their recognition sequences and cut sites) could be cloned into a plasmid cut with BgIII?