Biological Classification

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

Lichens are well known combination of an alga and a fungus where fungus has

1. a saprophytic relationship with the alga
2. an epiphytic relationship with the alga
3. a parasitic relationship with alga
4. a symbiotic relationship with alga

When a fresh-water protozoan possessing a contractile vacuole, is placed in a glass containing marine water, the vacuole will

1. increase in number
2. disappear
3. increase in size
4. decrease in size

Which one of the following statements about viruses is correct?

1. Viruses possess their own metabolic system.
2. All viruses contain both RNA and DNA.
3. Viruses are obligate parasites.
4. Nucleic acid of viruses is known as capsid.