Q1. The only snake that builds a nest is [1995]
(a) Chain Viper
(b) King cobra
(c) Krait
(d) Saw-scaled viper
Ans. (b)
Exp. The only snake that builds a nest is king cobra. It builds a nest made of leaves and branches and guards it until the eggs hatch. The female gathers large quantities of fallen leaves and other rotten vegetation into which she lays clutch of upto 50 eggs. These eggs are guarded over for full incubation period.
Q2. Biologists have so far known, found and identified a large number of species in the plant and animal kingdom. In terms of number, the largest found and identified so far is from among the (1996)
(a) bacteria
(b) insects
(c) plants
(d) fungi
Ans. (b)
Exp. In terms of number, the largest found and identified species is from among the insects. Class-Insecta of the animal kingdom is so far known to have maximum number of species in plant and animal kingdom. Insect biodiversity accounts for a large proportion, about 70% of total animals. The number of insect is 1025000, the knowledge about protists, archaea, bacteria and virus is quite fragmentary. Number of plants and fungi identified till date is 270000 and 72000 respectively.
Q3. Which one of the following types of microorganisms is most widely used in industries? (1998)
(a) Bacteria
(b) Bacteria and fungi
(c) Bacteria and algae
(d) Bacteria, microalgae and fungi
Ans. (d)
Exp. Bacteria, microalgae and fungi are the types of microorganisms widely used in industries. Bacteria like Lactobacillus sp. is used in the manufacturing of yogurt. Apart from this, various other bacteria are commercially useful in preparing variety of products.
Most of the algae are used as single cell protein (i.e, Spirulina) to prepare various food supplements. Different drugs such as penicillin, are manufactured from fungi Penicillium notatum. Yeast is also a fungus used in the manufacturing of alcohol by fermentation process in industries.
Q4. Which one of the following is a useful functional association between fungi and the roots of higher plants? (1999)
(a) Biofertilizer
(b) Coralloid root
(c) Lichen
(d) Mycorrhiza
Ans. (d)
Exp. Mycorrhiza is a useful functional association between fungi and the roots of higher plants.
A mycorrhiza is a mutual association between a fungus and root of higher plants in gymnosperms (naked seed plants) and angiosperm (flowering plants). This association provide many benefits to plants such as: resistance to root borne pathogens, tolerance to salinity and drought, absorption of phosphorus from soil, etc. This also acts as a main source of biofertilizers.
Q5. Which one of the following is monogamous? (2002)
(a) Wolf
(b) Walrus
(c) Seal
(d) Deer
Ans. (a)
Exp. Wolf is monogamous in nature among all other options given.
Monogamy is a form relationship in which an individual has only one partner during their lifetime or at any one time. It is
rare in the animal kingdom. Monogamous animals are beavers, wolves and some bats.
Walrus, seal and deer are not monogamous. Some deer (European roe deer) are rarely monogamous.
Q6. Which one of the following statements is not correct? (2002)
(a) All echinoderms are viviparous
(b) Roundworm has no circulatory system
(c) In bony fishes, swim bladder is usually present (d) In cartilaginous fishes, fertilization is internal
Ans. (a)
Exp. Statement (a) is not correct as the animals of phylum-Echinodermata are oviparous, (i.e. they are egg laying). They also have the ability of regeneration. The body structure in most echinoderms is star-shaped and contains stinging cells on their surface.
Q7. Which one of the following statements is correct?
(a) Prions are the smallest free-living cells
(b) The cell wall of Mycoplasmas is made up of amino sugars
(c) Viroid consist of single-stranded DNA/RNA molecule
(d) Rickettsia lacks cell wall
Ans. (c)
Exp. Statement give in option (c) is correct. Viroid is a small infective segment of nucleic acid, usually RNA. They are independent pathogenic organisms present in the environment. They cause diseases like potato spindle tuber disease, etc.
Other statements are incorrect and can be corrected as prion is an infectious pathogenic agent devoid of nucleic acid and composed mainly of proteins. Mycoplasmas lack a cell wall while Rickettsia’s possess a cell wall.
Q8. Ticks and mites are actually
(a) arachnids
(b) insects
(c) crustaceans
(d) myriapods
Ans. (a)
Exp. Ticks and mites are actually arachnids. Scorpion, spider, ticks and mites occur under class- Arachnida of phylum- Arthropoda. Crustaceans are the types of small arthropod individuals belong to Myriapod. It is a sub-phylum of arthropods containing millipedes, centipedes and others. Insects come under class-Insects in the same phylum- Arthropoda. They from the largest group within the phylum.
Q9. Consider the following statements.(2002)
- Tapeworm is a hermaphrodite.
- Roundworm has separate sexes.
- Filaria is caused by a nematode.
- Guinea worm is an annelid.
Which of these are correct?
(a) 1 and 2
(b) 3 and 4
(c) 1, 2 and 3
(d) 2, 3 and 4
Ans. (c)
Exp. Statements (1), (2) and (3) are correct.
Tapeworms are hermaphrodite i.e., both male and female reproduction organs are present in same individual.
Roundworms are unisexual i.e. they have separate sexes.
Filaria is caused by Wuchereria bancrofti, which is a parasitic nemotode.
Statement 4 is incorrect because, Guinea worm, Dracunculus medinensis is a long and thin nematode, not an annelid.
This worm causes dracunculiasis or guinea-worm disease.
The disease is transmitted through drinking contaminated water.
Q10. Octopus is (2004)
(a) an arthropod
(c) a hemichordate
(b) an echinoderm
(d) a mollusc
Ans. (d)
Exp. Octopus is a mollusc. This is an animal of phylum Mollusca. Most molluscs have hard shell that protects their soft body. Although in some of them, the shell is missing of Bardly visible, e.g., Octopus, oysters, etc. Octopus has octopod structure in which arms are spined and contains several tentacles (a flexible limb or appendage in an animal used for moving) over it. This ejects an inky fluid in water for the purpose of defence from enemies. Octopus can also change its body colour.
Q11. Consider the following statements.
- The common blue-green algae, Spirogyra and Ulothris are found in both freshwater ponds and oceans.
- The Chameleon can look ahead with one eye and at the same time look behind with another.
Which of these statements is/are correct?
(a) Only 1
(b) Both 1 and 2
(c) Only 2
(d) Neither 1 nor 2
Ans. (c)
Exp. Statement (2) is correct.
This is because the Chameleon can actually see forward and backward at the same time with different eyes. They can move their eyes completely independently of one another or can see in almost any direction giving them almost 360 vision. They can also focus their eyes and can enlarge what they are looking at just like camera lens with a zoom. Statement (1) is incorrect as Spirogyra and Ulothrix are not categorised as blue-green algae they instead belong to the class-Chlorophyceae (green algae).
Q12. Among the following, which one lays eggs and does not produce young ones directly? (2008)
(a) Echidna
(b) Kangaroo
(c) Porcupine
(d) Whale
Ans. (a)
Exp. Among the given mammals, echidna lays eggs and does not produce young ones directly. Echidna is the only egg-laying (i.e., oviparous mammal) known as monotremes. The female lays a single, soft-shelled, leathery egg. twenty-two days after mating and deposits it directly into her pouch. These animals are placed in group called metatherians. They form the connecting link between prototherian and eutherian.
Q13. In which one of the following kinds of organisms is the phenomenon found wherein the female kills the male after copulation (2008)
(a) Dragon fly
(b) Honeybee
(c) Spider
(d) Pit viper
Ans. (c)
Exp. The phenomenon wherein the female kills the male after copulation is found in spiders (arachnid). This phenomenon is termed as sexual cannibalism. It is a special case in which a female organism kills and consumes male of the same species, after copulation. Although other forms of cannibalism are widespread in the animal kingdom.
Q15. For which one of the following snakes, the diet mainly composed of other snakes? (2008)
(a) Krait
(c) Rattle snake
(b) Russell’s viper
(d) King cobra
Ans. (d)
Exp. King cobra diet is mainly composed of other snake (such as pythons, tree snakes and other venomous species). In captivity, the king cobra are usually raised on mice and rats, birds and mammals. If fed this diet from a young age, most accept it readily and may even refuse to eat other snakes when they reach the adulthood.
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