Black (stem) rust of wheat is caused by:
1. Ustilago nuda
2. Puccinia graminis
3. Xanthomonas oryzae
4. Alternaria solani
Select the correct combination of the statements (a-d) regarding the characteristics of certain organisms:
(a) | Methanogens are archaebacteria that produce methane in marshy areas |
(b) | Nostoc is a filamentous blue-green alga that fixes atmospheric nitrogen |
(c) | Chemosynthetic autotrophic bacteria synthesize cellulose from glucose |
(d) | Mycoplasma lack a cell wall and can survive without oxygen |
The correct statements are:
1. | (a), (b) and (c) | 2. | (b), (c) and (d) |
3. | (a), (b) and (d) | 4. | (b) and (c) |
Given below is the diagram of a bacteriophage. In which one of the options, all the four parts A, B, C and D are correct?
A | B | C | D | |
1. | Sheath | Collar | Head | Tail fibres |
2. | Head | Sheath | Collar | Tail fibres |
3. | Collar | Tail fibres | Head | Sheath |
4. | Tail fibres | Head | Sheath | Collar |
In the five-kingdom classification, Chlamydomonas and Chlorella have been included in:
1. | Algae | 2. | Plantae |
3. | Monera | 4. | Protista |
Which one of the following sets of items in options 1 – 4 are correctly categorized with one exception in it?
ITEMS | CATEGORY | EXCEPTION | |
1. | Kangaroo, Koala, wombat | Australian marsupials | Wombat |
2. | Plasmodium, Cuscuta, Trypanosoma | Protozoan parasites | Cuscuta |
3. | Typhoid, Pneumonia, Diphtheria | Bacterial diseases | Diphtheria |
4. | UAA, UAG, UGA | Stop codons | UAG |
How many organisms in the list given below are autotrophs?
Lactobacillus, Nostoc, Chara, Nitrosomonas, Nitrobacter, Streptomyces, Sacharomyces, Trypanosoma, Porphyra, Wolfia
1. Five
2. Six
3. Three
4. Four
Auxospores and hormocysts are formed respectively, by:
1. Some cyanobacteria and many diatoms
2. Several diatoms and a few cyanobacteria
3. Several cyanobacteria and several diatoms
4. Some diatoms and several cyanobacteria
There exists a close association between the alga and the fungus within a lichen. The fungus:
1. | Provides food for the alga |
2. | Provides protection, anchorage and absorption for the alga |
3. | Fixes the atmospheric nitrogen for the alga |
4. | Releases oxygen for the alga |
Barophilic prokaryotes:
1. | Grow slowly in highly alkaline frozen lakes at high altitudes |
2. | Grow and multiply in very deep marine sediments |
3. | Readily grow and divide in seawater enriched in any soluble salt of barium |
4. | Occur in water containing high concentrations of barium hydroxide |
What is correct for the stages of Puccinia:
1. Telia and aecia on wheat
2. Telia and uredo stage on wheat
3. Telia and aecia on barberry
4. None