Microbiology Multiple Choice Questions on “Protozoa – Reproduction”.
1. Which of the following type of fission takes place in flagellates?
A. longitudinal
B. right angle to the cell axis
C. transverse
D. cytoplasm protrudes from the aperture
Answer: A
Clarification: In flagellates, with the exception of the dinoflagellates, fission is longitudinal along the major body axis. Since the flagella themselves are incapable of division, they must be regenerated from the basal bodies.
2. Which of the following does not take place in transverse fission?
A. fission occurs at the right angle to the long cell axis
B. equatorial furrow appears
C. cytoplasm protrudes from the aperture
D. constriction occurs forming two daughter cells
Answer: C
Clarification: In transverse fission which is characteristic for ciliates, fission occurs at a right angle to the long axis of the cell. An equatorial furrow appears first which separates the surface cell layer into an anterior and a posterior half. A constriction follows, leading to the separation of two daughter cells.
3. During asexual binary fission the macronucleus divides by mitotic division.
A. True
B. False
Answer: B
Clarification: In ciliates, during asexual binary fission the diploid micronucleus divides normally by mitotic division. The macronucleus undergoes DNA synthesis and divides into two portions without the regular reduplication of the chromosomes(amitosis).
4. Plasmodium divides by which of the following method most commonly?
A. Binary fission
B. Multiple fission
C. Budding
D. Regeneration
Answer: B
Clarification: The malarial parasite, Plasmodium divides by the process of multiple fission where it is known as schizogony and serves to spread the parasite quickly in the host.
5. The swarming daughter cells possess special locomoter organelles like the parent cell.
A. True
B. False
Answer: B
Clarification: The swarming daughter cells differ from the parent cell not only in a lower degree of differentiation but also in the possession of special locomotor organelles.
6. Definite exogenous budding occurs in which of the following species of protozoa?
A. foraminifera
B. radiolaria
C. suctorians
D. heliozoa
Answer: C
Clarification: Definite exogenous budding is seen in suctorians when a portion or portions of an adult sessile suctorian bud from the parent, develop cilia and swim away.
7. When the gametes are morphologically alike, they are called ______________
A. isogametes
B. anisogametes
C. macrogametes
D. microgametes
Answer: A
Clarification: When the gametes (which develop from trophozoites) are morphologically alike, they are called isogametes. When they are unlike they are known as isogametes.
8. Long,slender bodies with an oval nucleus and capable of producing new infection are known as _________________
A. ookinetes
B. sporozoites
C. anisogametes
D. spermatozoa
Answer: B
Clarification: Anisogamy in Plasmodium vivax results in the formation of ookinetes or motile zygotes which give rise to a large number of sporozoites which are long, slender bodies with an oval nucleus and firm cuticle, capable of producing the new infection.
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