Biological Classification

What is common about Trypanosoma, Noctiluca, Monocystis and Giardia?

1. These are all parasites
2. These are all unicellular protists
3. They have flagella
4. They produce spores

The causative agent of mad-cow disease is a-

1. Virus
2. Bacterium
3. Prion
4. Worm

The bacterium ( Clostridium botulinum) that causes botulism is-

1. A facultative aerobe
2. An obligate aerobe
3. A facultative anaerobe
4. An obligate anaerobe

Barophilic prokaryotes

1. grow and multiply in very deep marine sediments
2. occur in water containing high concentrations of barium hydroxide
3. readily grow and divide in sea water enriched in any soluble salt of barium
4. grow slowly in highly alkaline frozen lakes at high altitudes.

There exists a close association between the alga and the fungus within a lichen. The fungus

1. provides protection, anchorage and absorption for the alga
2. provides food for the alga
3. fixes the atmospheric nitrogen for the alga
4. releases oxygen for the alga

Auxospores and hormogonia are formed, respectively, by

1. some diatoms and several cyanobacteria
2. some cyanobacteria and many diatoms
3. several cyanobacteria and several diatoms
4. several diatoms and a few cyanobacteria.

Match items in column I with those in column II. Select the correct answer from the following.

1. (A) - (L); (B) - (J); (C) - (M); (D) - (N); (E) - (K)
2. (A) - (K); (B) - (J); (C) - (L); (D) - (M); (E) - (N)
3. (A) - (N); (B) - (L); (C) - (K); (D) - (N); (E) - (J)
4. (A) - (J); (B) - (K); (C) - (N); (D) - (L); (E) - (K)

Which of the following unicellular organisms has a macronucleus for trophic function and one or more micronuclei for reproduction?

1. Euglena
2. Amoeba
3. Paramecium
4. Trypanosoma

Which of the following statements is not true for retroviruses?

1. DNA is not present at any stage in the life cycle of retroviruses.
2. Retroviruses carry gene for RNA-dependent DNA polymerase.
3. The genetic material in mature retroviruses is RNA.
4. Retroviruses are causative agents for certain kinds of cancer in man.

Viruses that infect bacteria multiply and cause their lysis, are called

1. lysozymes
2. lipolytic
3. lytic
4. lysogenic