Biological Classification

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.

Tobacco mosaic virus is a tubular filament of size

1. 300 10 nm
2. 300 5 nm
3. 300 20 nm
4. 700 30 nm

Viruses are no more "alive" than isolated chromosomes because

1. they require both RNA and DNA
2. they both need food molecules
3. they both require oxygen for respiration
4. both require the environment of a cell to replicate.