Interview MCQ Set 1
1. The primary producers in the marine system are ________________
d) cyanobacteria and eukaryotic algae
Answer: d [Reason:] The primary producers in the marine system are cyanobacteria and eukaryotic algae which predominate in the phytoplankton.
2. The primary producers transform radiant energy into heat energy.
Answer: b [Reason:] The primary producers through photosynthesis, are capable of transforming radiant energy into chemical energy (organic compounds).
3. The biological activity of an aquatic ecosystem is dependent upon which of the following factors?
a) number of primary producers
b) amount of chemical energy produced
c) rate of primary production
d) number of deaths of organisms
Answer: c [Reason:] The biological activity of an aquatic ecosystem is dependent upon the rate of primary production performed by the photosynthetic organisms.
4. n which of the following water bodies, the role of photosynthetic organisms is considerably reduced?
Answer: c [Reason:] In shallow estuaries the role of photosynthetic organisms as primary producers is considerably reduced. Plant growth from the shoreline contributes leaves,stems, and roots of vegetation and other organic detritus.
5. Which of the following aquatic organisms contribute in a small amount to the shallow estuary food web?
a) benthic algae
Answer: a [Reason:] Phytoplankton and benthic algae make a small contribution to the food supply in the food web of shallow estuaries.
6. Which among the following are referred to as the “pasture of the sea”?
Answer: d [Reason:] Plankton, particularly phytoplankton, has been referred to as the “pasture of the sea”. Fish, whales, and squids feed directly on plankton or on larger plankton-feeding animals.
7. The term fertility of oceans is used to express the capacity for production of inorganic matter.
Answer: b [Reason:] The term fertility of oceans is used to express the capacity for the production of organic matter by the organisms present in these waters.
8. What amount of dry organic matter is produced by the deep ocean areas?
Answer: c [Reason:] The terrestrial environment produces 1 to 10 g of dry organic matter per square meter per day compared to 0.5 g for the deep ocean areas.
9. Which among the following factors are limiting growth of phytoplankton organisms?
a) carbon dioxide
b) radiant energy
d) radiant energy,nitrogen
Answer: d [Reason:] The factors generally limiting growth are radiant energy, nitrogen and phosphorus, and the trace elements. The nitrogen, phosphorus and trace elements are made available through the mineralization reactions of microorganisms.
10. Which among the following oceans is the most richest in life?
a) Antarctic Ocean
b) Atlantic Ocean
c) Pacific Ocean
d) Indian Ocean
Answer: a [Reason:] The Antarctic Ocean is described as being richer in life than any other major oceanic area. The richness of nutrients in this region is attributable to the mixing of the waters of the Atlantic, Pacific, and Indian Oceans.
11. In which of the following water bodies, fertility is high?
a) open sea
b) coastal regions
Answer: b [Reason:] Although coastal and estuarine regions provide a less stable physical environment, their fertility exceeds that of the open sea because of the large amounts of nutrients available.
12. Which of the following product is not obtained from dissimilation of organic matter under aerobic conditions?
Answer: c [Reason:] Under aerobic conditions the principal products resulting from dissimilation of organic compounds are ammonium, carbon dioxide, sulphate, and phosphate.
13. Which of the following organism have siliceous skeletons?
Answer: c [Reason:] Radiolaria and silicoflagellates have siliceous skeletons whereas foraminifera and coccolithophores produce calcareous skeletons.
Interview MCQ Set 2
1. Roll-tube technique is used to isolate ___________
d) stringent anaerobes
Answer: d [Reason:] Roll-tube technique which is a modification of streak-plate technique is used to isolate stringent anaerobes.
2. In pour-plate method,the medium should be maintained at what temperature?
a) 37 degree C
b) 67 degree C
c) 45 degree C
d) 0 degree C
Answer: c [Reason:] In pour plate method, the medium is maintained in a liquid state at a temperature of 45 degree C to allow thorough distribution of inoculum.
3. Which of the following method can be used to determine the number of bacteria quantitatively?
c) Pour plate
d) Pour-plate and spread plate
Answer: d [Reason:] Due to higher degree of dilution, pour-plate and spread-plate techniques may be performed in a quantitative manner to determine the number of bacteria present in a specimen.
4. Dilution of the mixed culture is a common step in all the three methods: the streak-plate,the spread-plate and the pour-plate technique.
Answer: b [Reason:] The streak-plate technique does not require dilution as a portion of the mixed culture is placed on the surface of an agar medium and streaked across the surface.
5. Which of the following are not performed in lyophilization?
a) agar slant is covered with mineral oil
b) cell suspension is frozen at -60 degree to -78 degree C
c) vials are connected to high-vacuum line
d) bacterial sample is dehydrated
Answer: a [Reason:] In lyophilization or freeze-drying, a dense cell suspension is placed in small vials and frozen at -60 degree to -78 degree C. The vials are then connected to a high-vacuum line. The ice present in the frozen suspension sublimes under the vacuum and results in dehydration of the bacteria.
6. Which of the following is a function of cryoprotective agents?
a) for long-term preservation of cultures
b) prevents cell damage due to ice crystal formation
c) prevents formation of ice
d) to trap the liquid nitrogen
Answer: b [Reason:] For preservation at low temperatures the cells are prepared as a dense suspension in a medium containing cryoprotective agent such as glycerol or dimethyl sulphoxide which prevents cell damage due to ice crystal formation.
7. What is the temperature of liquid nitrogen?
a) -120 degree C
b) 0 degree C
c) -150 degree C
d) -196 degree C
Answer: d [Reason:] Liquid nitrogen has a temperature of -196 degree C and is used for storage of culture medium.
8. Nichrome loop wire is used in which of the following techniques?
d) Roll-tube technique
Answer: b [Reason:] In streak plate technique, with the help of a nichrome loop wire, a portion of mixed culture is placed on the surface of an agar medium and streaked across the surface.
9. Which device is used to pick a single bacterial cell from a mixed culture?
Answer: d [Reason:] A device called the micromanipulator can be used in conjunction with a microscope to pick a single bacterial cell from a mixed culture. The micro manipulator permits the operator to control the movements of a micropipette or a microprobe so that a single cell can be isolated.
Interview MCQ Set 3
1. Members of order Diplomonadida have how many flagella?
a) 2 to 4
b) 6 to 8
c) 2 to 8
d) 1 to 2
Answer: b [Reason:] Members of the order Diplomonadida have bilateral symmetry and 6 to 8 flagella.
2. Trypanosoma belongs to which of the following order?
Answer: a [Reason:] Trypanosoma belongs to the order Kinetoplastida which are grouped with other organisms due to the presence of kinetoplast (an extracellular region of DNA associated with the mitochondrion).
3. The Trichomonads found in the intestine are ___________________
a) Trichomonas buccalis
b) Trichomonas hominis
c) Trichomonas vaginalis
d) Trichonympha campanula
Answer: b [Reason:] Trichomonas hominis are found in the intestine where they may be associated with with diarrheal conditions.
4. African sleeping sickness is transmitted by which of the following agents?
a) biting insects
b) sexual means
c) tsetse fly
d) bloodsucking insects
Answer: c [Reason:] Trypanosoma rhodesiense are transmitted by the tsetse fly and cause African sleeping sickness.
5. Amoebas carry on a special kind of respiration in the form of exchange of gases between the cell and the surrounding field.
Answer: a [Reason:]Amoebas carry on a special kind of respiration in the form of an exchange of gases between the cell and the surrounding fluid, for at rather regular intervals vacuoles apparently containing some carbon dioxide in solution are expelled from the cell through an opening that develops in the cell membrane.
6. Which of the following protozoa construct shells of silica?
Answer: b [Reason:]Radiolarians, like foraminiferans, are marine forms, but most of them construct shells of silica.Deposits of their skeletons are incorporated in rocks formed in areas where they have ocurred in abundance.
7. The Sporozoa belongs to which of the following phylum?
Answer: d [Reason:] The Sporozoa belongs to the phylum Apicomplexa .All sporozoa are parasitic for one or more animal species.
8. What is the shape of Paramecium?
c) spindle shaped
Answer: b [Reason:] Paramecia are easily distinguished by their characteristic shape, which has been likened to that of slipper.The anterior end of the cell is rounded and the posterior end is slightly pointed giving it a slipper-like shape.
9. Undigested particles are eliminated from the cell through the ___________________
b) contractile vacuole
d) cell membrane
Answer: c [Reason:] In Paramecium the undigested particles are eliminated from the cell through the cytoproct.Waste fluids are collected in the contractile vacuoles.
10. During binary fission in Paramecium, the rear daughter cell receives a new gullet?
Answer: b [Reason:] Paramecia reproduce asexually by binary fission in which the rear daughter cell receives the gullet of the parent, and a new gullet is formed for the other new cell.
11. Which of the following comprises large cone-shaped protozoa?
Answer: c [Reason:] The genus Stentor comprises large cone-shaped protozoa that move about freely but attach to some object by a tapered lower end while feeding.
Interview MCQ Set 4
1. Which of the following is the first step in replication by bacterial phages?
d) assembly and release
Answer: a [Reason:] The first step in infection of a host bacterial cell by a phage is adsorption.Infection of a host bacterial cell cannot occur without adsorption.
2. At what temperature incubation is required for the adsorption of phage T4 and DNA injection into E.coli?
a) 50 degree C
b) 15 degree C
c) 37 degree C
d) 80 degree C
Answer: c [Reason:] Phage T4 adsorption and DNA injection into E.coli spheroplasts require the phage particles to be incubated with spheroplasts at 37 degree C for 10 mins.
3. Which of the following is the correct sequence of events in replication by bacterial phage?
a) adsorption,pinning,DNA injection,sheath contraction
b) adsorption,pinning,sheath contraction,DNA injection
c) adsorption,absorption,sheath contraction,pinning
d) absorption,adsorption,DNA injection
Answer: b [Reason:] The first step in the process of replication by bacterial phage is adsorption to the host cell.This is followed by pinning when the tail pins attach to the cell surface.Then the sheath contracts driving the tail core into the cell through the cell membrane and then the virus injects its DNA into the cell.
4. The protein coat of the virus remains outside the host cell.
Answer: a [Reason:] The protein coat, which forms the phage head, and the tail structure of the virus remains outside the cell.
5. The delayed early genes codes for which of the following enzymes?
a) phage enzymes
b) RNA polymerase
Answer: a [Reason:] Delayed early genes code for phage enzymes which produce unique phage DNA constituents such as 5-hydroxymethylcytosines; which destroy precursors of cytosine deoxynucleotides so that no bacterial cytosine will be incorporated into phage DNA.
6. Which of the following enzymes transcribe late genes?
c) RNA polymerase
d) restriction enzymes
Answer: c [Reason:] Delayed early genes code for second altered RNA polymerase that will transcribe the late genes.
7. In the growth curve of plaque-forming units, the time from infection until lysis is known as ____________________
a) eclipse period
b) rise period
c) burst period
d) latent period
Answer: d [Reason:] No newly released extracellular phages can be seen until lysis begins; the time from infection until lysis is the latent period.
8. What is the colour of the plaque formed?
Answer: c [Reason:] Growth of phage is indicated by the appearance of plaques that are clear zones, unlike the otherwise opaque growth of the host bacterium.
Interview MCQ Set 5
1. Which among the following are asexual spores?
Answer: a [Reason:] Blastospores are asexual spores and are formed by budding.
2. Aplanospores are ___________________
a) motile sporangiospores
b) nonmotile sporangiospores
Answer: b [Reason:] Aplanospores are nonmotile sporangiospores.Sporangiospores are single-celled spores and are formed within sporangium.
3. Which among the following are spores formed by budding?
Answer: c [Reason:] Blastospores are asexual spores and are formed by budding.
4. Spores formed by sexual reproduction on a club-shaped structure are _______________
Answer: c [Reason:] Basidiospores are single-celled spores borne on a club-shaped structure called a basidium.
5. Asexual fruiting bodies have name such as ________________
Answer: b [Reason:] Fruiting bodies are highly organized protective structures that surround the asexual and sexual spores. Asexual fruiting bodies have names such as acervulus and pycnidium.
6. There are one or more oospheres in each oogonium.
Answer: a [Reason:] Oospheres are eggs formed within a special female structure, the oogonium.There are one or more oospheres in each oogonium.
7. How many ascospores are present in each ascus?
Answer: d [Reason:] Ascospores are single-celled spores produced in a sac called an ascus.These are usually eight ascospores in each ascus.
8. Which of the following spores are formed at the tips of sterigmata?
Answer: c [Reason:] Basidiospores are formed exogenously at the tips of the special outgrowths called sterigmata. Usually four spores are formed at the tip of each sterigma.
9. The process of fusion of nuceus of two mating types is known as plasmogamy.
Answer: b [Reason:] The two haploid nuclei of two mating types fuse together to form a diploid nucleus and this process is known as karyogamy.
10. In which of the following process does the male nucleus migrates through a fertilization tube into the female gametangium?
a) Gametic copulation
b) Gamete-gametangial copulation
c) Gametangial copulation
d) Somatic copulation
Answer: b [Reason:] In gamete-gametangial copulation, the two gametangia come into contact but do not fuse; the male nucleus migrates through a pore or fertilization tube into the female gametangium.
11. Which of the following spores are formed by disjointing of hyphal cells?
Answer: c [Reason:] Oidia or arthrospores are single-celled spores formed by disjointing of hyphal cells.