21. Which one of the following is correct about microbial growth medium?
22. Which of the following statements are correct?
P. Viruses can play a role in causing human cancer.
Q. A tumor suppressor gene can be turned off without any change in its DNA sequence.
R. Alteration in miRNA expression levels contributes to the development of cancer.
P. Viruses can play a role in causing human cancer.
Q. A tumor suppressor gene can be turned off without any change in its DNA sequence.
R. Alteration in miRNA expression levels contributes to the development of cancer.
23. Determine the correctness or otherwise of the following Assertion (A) and Reason (R).
Assertion: Gram negative bacteria show staining with safranin.
Reason: Gram negative bacteria have an outer membrane with lipopolysaccharides.
Assertion: Gram negative bacteria show staining with safranin.
Reason: Gram negative bacteria have an outer membrane with lipopolysaccharides.
24. Match the organisms in Group I with the characteristics in Group II.
Group I
Group II
P. Methanococcus
1. Halophile
Q. Dunaliella
2. Acidophile
R. Sulfolobus
3. Mesophile
S. Escherichia
4. Barophile
| Group I | Group II |
| P. Methanococcus | 1. Halophile |
| Q. Dunaliella | 2. Acidophile |
| R. Sulfolobus | 3. Mesophile |
| S. Escherichia | 4. Barophile |
25. Match the microorganisms in Group I with their fermentation products in Group II.
Group I
Group II
P. Leuconostoc mesenteroides
1. Cobalamin
Q. Rhizopus oryzae
2. Sorbose
R. Gluconobacter suboxydans
3. Dextran
S. Streptomyces olivaceus
4. Lactic acid
5. Butanol
| Group I | Group II |
| P. Leuconostoc mesenteroides | 1. Cobalamin |
| Q. Rhizopus oryzae | 2. Sorbose |
| R. Gluconobacter suboxydans | 3. Dextran |
| S. Streptomyces olivaceus | 4. Lactic acid |
| 5. Butanol |
26. Diphtheria toxin, tetracycline and streptomycin inhibit
27. Under stress conditions bacteria accumulate
28. Match the compounds in Group I with the correct entries in Group II.
Group I
Group II
P. Cyanide
1. K+ ionophore
Q. Antimycin A
2. Electron transfer from cytochrome b to cytochrome c1
R. Valinomycin
3. F1 subunit of ATP synthase
S. Aurovertin
4. Cytochrome oxidase
5. Adenine nucleotide translocase
| Group I | Group II |
| P. Cyanide | 1. K+ ionophore |
| Q. Antimycin A | 2. Electron transfer from cytochrome b to cytochrome c1 |
| R. Valinomycin | 3. F1 subunit of ATP synthase |
| S. Aurovertin | 4. Cytochrome oxidase |
| 5. Adenine nucleotide translocase |
29. Which combination of the following statements is correct for cyanobacteria?
P. They can perform oxygenic photosynthesis.
Q. Usually filamentous forms are involved in nitrogen fixation.
R. Nitrogen fixation occurs in heterocyst.
S. They cannot grow in a mineral medium exposed to light and air.
P. They can perform oxygenic photosynthesis.
Q. Usually filamentous forms are involved in nitrogen fixation.
R. Nitrogen fixation occurs in heterocyst.
S. They cannot grow in a mineral medium exposed to light and air.