Biological Classification Class 11 Biology Exam Questions

Please refer to Biological Classification Class 11 Biology Exam Questions provided below. These questions and answers for Class 11 Biology have been designed based on the past trend of questions and important topics in your class 11 Biology books. You should go through all Class 11 Biology Important Questions provided by our teachers which will help you to get more marks in upcoming exams.

Class 11 Biology Exam Questions Biological Classification

Class 11 Biology students should read and understand the important questions and answers provided below for Biological Classification which will help them to understand all important and difficult topics.

Objective Type Questions

Question. A protein rich layer which makes the body of Euglenoids flexible is called
a. Pellicle
b. Murein
c. Cellulose plate
d. Pseudopodia

Question. Trypanosoma brucei produces:
a. A disease of animals
b. Kala-azar
c. Dysentery
d. Sleeping sickness

Question. Trichonympha is a symbiont in alimentary canal of:
a. Termite
b. Snails
c. Hermit Crab
d. Earthworm

Question. Quinine is got from bark of:
a. Cinchona officinalis
b. Ferula asafoetida
c. Curcuma domestica
d. Atropa belladona

Question. From which of the following most of the antibiotics are prepared?
a. Fungi
b. Plants
c. Actinomycetes
d. Archaebacteria

Question. White lust of crucifer is caused by:
a. Albugo candida
b. Alterneria solani
c. Rhizopus
d. Mucor

Question. Primary host of Puccinia fungi:
a. Wheat
b. Barley
c. Rye
d. Musturd

Question. Ergot of rye is caused by:
a. Claviceps
b. Phytophthora
c. Puccinia
d. Ustilago

Question. Dolipore septum is the characteristics of:
a. Myxomycetes
b. Basidiomycetes
c. Ascomycetes
d. Phycomycetes

Question. Considering two-kingdom classification system, the organisms that are included in kingdom Plantae are
a. Volvox, Amoeba and Paramecium
b. Golgi bodies, algae and fungi
c. Amoeba, bacteria and fungi
d. Fungi, bacteria and algae

Question. Cell wall of kingdom Plantae organisms is made up of
a. Chitin
b. Cellulose
c. Polysaccharides
d. Lipids

Question. Which of the following is true for Kingdom Animalia?
a. Cell wall are present in animal cell.
b. Their mode of nutrition is holozoic.
c. They do not follow a definite growth pattern.
d. All of them are capable of locomotion.

Question. Virion is
a. Nucleic acid of virus
b. Antiviral agent
c. Protein of virus
d. Completely assembled virus outside host

Question. Viruses are
a. Obligative parasite
b. Facultative
c. Either facultative or obligative
d. None of these

Question. Viruses that infect animals have which type of genetic material?
a. Either single or double stranded RNA
b. Either single/double stranded RNA or double stranded DNA.
c. Single stranded DNA
d. None of these

Question. Viroid was discovered by
a. Ernst Mayr
b. Norman E. Borlaug
c. T. O. Diener
d. None of these

Question. Match the following
A. Saxicolous lichen 1. Grows on tree bark
B. Corticolous lichen 2. Grows on soil
C. Terricolous lichen 3. Grows on rock
a. A-3 B-1 C-2
b. A-3 B-2 C-1
c. A-2 B-3 C-1
d. A-1 B-3 C-2

Question. In Rous Sarcoma Virus information flow is:
a. RNA → cDNA → Protein
b. cDNA → RNA → Protein
c. RNA → cDNA → Protein
d. cDNA → Protein → RNA

Question. Tailed bacteriophage is:
a. Motile on surface of plant leaves
b. Actively motile in water
c. Motile on bacterial surface
d. Nonmotile

Question. Virus was discovered by:
a. Stanley
b. Herellel
c. Ivanowski
d. Beijerinck

Question. White lust of crucifer is caused by:
a. Albugo candida
b. Alterneria solani
c. Rhizopus
d. Mucor

Question. Primary host of Puccinia fungi:
a. Wheat
b. Barley
c. Rye
d. Musturd

Question. Ergot of rye is caused by:
a. Claviceps
b. Phytophthora
c. Puccinia
d. Ustilago

Question. Dolipore septum is the characteristics of:
a. Myxomycetes
b. Basidiomycetes
c. Ascomycetes
d. Phycomycetes

Question. Considering two-kingdom classification system, the organisms that are included in kingdom Plantae are
a. Volvox, Amoeba and Paramecium
b. Golgi bodies, algae and fungi
c. Amoeba, bacteria and fungi
d. Fungi, bacteria and algae

Higher Order Questions

Question. Pulmonary tuberculosis is caused by
a. Escherichia coli
b. Pseudomonas aeruginosa
c. Mycobacterium
d. Streptococcus pneumoniae

Question. Subterranean masses of hyphae which pass the unfavourable periods in dormant stage are known as
a. Sclerotia
b. Mycelium
c. Rhizomorph
d. Puff balls

Question. Small proteins produced by vertebrate cells naturally in response to viral infections and which inhibit multiplication of viruses are called
a. Immunoglobulins
b. Interferons
c. Antitoxins
d. Lipoproteins

Question. Bacteria responsible for nitrificatin come under the following groups:
a. Bacillus
b. Vibrio
c. Coccus
d. Spirilla

Question. Bacteria were discovered by:
a. Robert Koch
b. A.V. Leeuwenhoek
c. Robert Hooke
d. Louis Pasteur

Question. The main difference in Gram (+)ve and Gram (-)ve bacteria resides in their:
a. Flagella
b. Cell membrane
c. Cytoplasm
d. Cell wall

Question. An obligate anaerobe is:
a. Ulothrix
b. Methane bacteria
c. Spirogyra
d. Onion

Question. Endospores develop in:
a. Bacillus and Clostridium
b. Saccharomyces and Clostridium
c. Mnococcus and Clostridium
d. Mucor and Bacillus

Question. Match the columns and find the correct answer:

Column I	Column II
A. Streptomyces	1. Food poisoning
B. Rhizobium	2. Source antibiotics
C. Nitrosomonas	3. Nitrogen fixation
D. Acetobacter	4. Nitrification
	5. Vinegar synthesis

a. A-2 B-3 C-4 D-5
b. A-5 B-2 C-3 D-4
c. A-2 B-3 C-1 D-5
d. A-4 B-5 C-1 D-3

Question. Entamoeba coil causes:
a. None
b. Diarrhoea
c. Dysentery
d. Pyorrhoea

Question. Recurrence of high temperature in malaria at intervals is due to completion of:
a. Exoerythrocytic schizogony
b. Sporogony
c. Gamogony
d. Erythrocytic schizogony

Question. Which of the following can be used as bacteriological filter?
a. Cymbella
b. Batrachospermum
c. Oscillatoria
d. Gelidium

Question. Chief producers in oceans are
a. Diatoms
b. Desmids
c. Archaebacteria
d. All of these

Question. Acellular slime mould:
a. Physarum
b. Physarella
c. Both of these
d. None of these

Question. Amoeba is found in:
a. Fresh water
b. Marine water
c. Dirty water
d. All of these

Question. Slime mould is characterized by the presence of
a. Elaters
b. Pseudoelaters
c. Capillitum
d. Capitulum

Question. Longitudinal binary fission found in
a. Euglena
b. Plasmodium
c. Planaria
d. Paramecium

Question. Amoeba secretes digestive enzymes for hydrolysing:
a. Protein
b. Starch
c. Fat
d. All the above

Question. Multiple fission in Plasmodium is:
a. Schizogony
b. Sproulation
c. Gamogamy
d. None of the above

Question. Infective stage of Entamoeba histolytica is:
a. Pre-cyst
b. Tetranucleate cyst
c. Uninucleate cyst
d. Trophozoite

Question. Haemozoin formed in malaria is produced by:
a. Globin part of haemoglobin
b. Dead leucocytes
c. Cryptozoites
d. Heme of haemoglobin

Question. What is not connected with reproduction of protozoans?
a. Cryptogamy
b. Autogamy
c. Schizogamy
d. Conjugation

Question. Malarial parasite is:
a. Polygenetic
b. Monogenetic
c. Digenetic
d. Monomorphic

Assertion & Reason Questions

Directions: These questions consist of two statements each, printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses.
A. If both Assertion and Reason are True and the Reason is a correct explanation of the Assertion.
B. If both Assertion and Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion and Reason are False.

Question. Assertion: Protozoans are believed to be primitive relatives of animals.
Reason: All protozoans are heterotrophs usually and live as predators or parasites.

Question. Assertion: Pili are surface structure of bacteria but not play a role in motility.
Reason: Pili is made up of pilin protein which is non contractile.

Question. Assertion: Eubacteria photosynthesis is not oxygenic (do not produce oxygen).
Reason: Eubacteria lack PS-II.

Question. Assertion: Diatomaceous earth is used in polishing, filteration of oil and syrups.
Reason: Diatoms are chief producer in ocean.

Question. Assertion: Dinoflagellates show water bloom.
Reason: Dinoflagellates float with the help of stored food.

Question. Assertion: Archaebacteria are called ancient bacteria.
Reason: Archaebacteria are presently living.

Question. Assertion: Slime moulds lack cell wall.
Reason: In reproductive phase, slime moulds contain cell wall.

Question. Assertion: Malarial fever appear at merozoite stage of Plasmodium.
Reason: The infective stage of Plasmodium is sporozoite.

Question. Assertion: Euglena is studied as an animal as well as a plant.
Reason: Euglena is more an animal than a plant.

Question. Assertion: Fungal cellulose or chitin is a polysaccharide.
Reason: It is made of acetyl glucosamine.

Question. Assertion: “Fungi imperfecti” does not show alternation of generation.
Reason: The diploid phase is only present.

Very Short Answer Type Questions :

Question. How is the five kingdom classification advantageous over the two kingdom classification?
Ans. The five kingdom classification, that is proposed by RH Whittaker is based upon cell structure, body structure (unicellular, multicellular), nutrition (autotrophic, heterotrophic) reproduction and way of living either aquatic, terrestrial, or arial and phylogenetic relationship.
So, it is more useful as compared to two kingdom system of classification which does not distinguish between prokaryotes and eukaryotes and no other kingdom except plant and animal are identified.

Question. In the five kingdom system of Whittaker, how many kingdoms are eukaryotes?
Ans. In the five kingdom classification given by Whittaker four kingdom belongs to eukaryotes, i.e., Protista, Fungi, Plantae and Animalia, except for the kingdom–Monera that belongs to prokaryotes.
Eukaryotic organism are those that possess
(i) An organised nucleus
(ii) Possess double envelop system
(iii) Presence of cell wall
(iv) Membrane bound organelles are present.

Question. Polluted water bodies have usually very high abundance of plants like Nostoc and Oscillitoria. Give reasons.
Ans. Polluted water bodies possess high algal growth due to the presence of nutrient. These nutrients increase the rapid growth of water plants, i.e., algae especially Nostoc and Oscillitoria, etc., and result in colonies. These colonies are generally surrounded by a gelatinous sheath and furtherleads to the formation of blooms in water bodies.

Question. Are chemosynthetic bacteria autotrophic or heterotrophic?
Ans. Chemosynthetic bacteria are capable of oxidising various inorganic substances such as nitrates, nitrites and ammonia and use the energy released for their ATP production. So, they are autotrophs and not heterotrophs.

Question. The common name of pea is simpler than its botanical (scientific) name Pisum sativum why then is the simpler common name not used instead of the complex scientific/botanical name in biology?
Ans. The common or vernacular names changes with the change in place, causing confusion regarding the identification of specific specimen, whereas the complex scientific names are in latin and universally accepted and understood.
Hence, scientific names are preferred over the common vernacular names.

Question. Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you place the slide under microscope and observe the following features
(a) Unicellular
(b) Well defined nucleus
(c) Biflagellate-one flagellum lying longitudinally and the other transversely
What would you identify it as? Can you name the kingdom it belongs to?
Ans. All unicellular eukaryotic organisms form a link between plants, and animals. There organisms possess a well defined nucleus with membrane bound organelles and reproduce either sexually or asexually.
The it presence of two flagella one placed longitudanally and other transversely in a furrow between wall plates makes this organisms to be placed under Kingdom–Protista.

Question. A virus is considered as a living organism and an obligate parasite when inside a host cell. But virus is not classified along with bacteria or fungi.
What are the characters of virus that are similar to non-living objects?
Ans. Viruses are considered as living when they are inside a host but outside any host they are referred to as non-living due to their
(a) inert nature
(b) inability to reproduce
(c) lack of cellular organisation
(d) inability for growth and cell division
These characters potraited by viruses make them identical to non-living organisms.Viruses are considered a connecting link between living and non-living organisms.

Question. What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?
Ans. Cyanobacteria are used in agricultural crop improvement because of their adicity to fix atmospheric nitrogen and make it available to the plants. This improves the yield of the crops and also reduces the cost of application of nitrogen fertilisers. e.g., Anabena and Nostoc.

Short Answer Type Questions :

Question. Neurospora an ascomycetes fungus has been used as a biological tool to understand the mechanism of plant genetics much in the same way as Drosophila has been used to study animal genetics. What makes Neurospora so important as a genetic tool?
Ans. Neurospora fungus was selected to be a very good tool in genetics because this fungus can be grown easily under laboratory conditions by providing ‘minimal medium’ like inorganic salts, carbohydrates source and vitamin (biotin).
Also under X-ray treatment the mutations can be easily introduced in the fungal cells and meiotic division can be easily seen.

Question. Cyanobacteria and heterotrophic bacteria have been clubbed together in eubacteria of kingdom–Monera as per the ‘five kingdom classification’ even though the two are vastly different from each other. Is this grouping of the two types of taxa in the same kingdom justified? If so, why?
Discuss the cellular composition of cyanobacteria and heterotrophic bacteria that make them introduced in eubacteria.
Ans. Although the two are vastly different from each other. They still bear some common
characters, on the basis of which they are introduced in eubacteria of kingdom–Monera.
These characters are as follows
(i) Both the groups do not possess well defined nucleus.
(ii) Nucleus lacks nucleous and nuclear membrane.
(iii) DNA (genetic material) lies freely in the cytoplasm.
(iv) They possess 70 S type of ribosomes.

Question. At a stage of their cycle, ascomycetes fungi produce the fruiting bodies like apothecium, perithecium or cleistothecium. How are these three types of fruiting bodies different from each other?
Discuss the type of fruiting bodies formed by ascomycetes fungus and differentiate accordingly on the basic of there structures.
Ans. Ascomycetes Consist of sporangial sac called ascus. Asci (singular-ascus) may occur freely or get aggregated with dikaryotic mycelium to form the fruitification called ascocarps.
The fruitification formed by asci are like

Question. Fungi are cosmopolitan, write the role of fungi in your daily life.
Discuss the role of fungi, with respect to its economical importance to humans.
Ans. Role of Fungi
Fungi are cosmopolitan in occurrance being present in air, water, soil over and inside animals and plants. The branch of biology dealing with the study of fungi is known as Mycology.
(i) Few fungi are used as nutritious and delicious food. e.g., Agaricus compestris
(ii) Saprophytic fungi lives upon dead organic matter and breaks complex substances into simple ones, that are absorbed by plants as nutrients.
(iii) Some fungi like Absidia, mucor and Rhizopus possess soil binding properties and make the soil good for cultivation.
(iv) They also provide pest resistence, e.g., Empusa, Ferinosa, etc.
(v) Yeast (Saccharomyces) has the property of fermentation, thus used in alcohol and dough preparation.

Question. What observable features in Trypanosoma would make you classify it under kingdom–Protista?
Discuss cell structure of Trypanosoma also discuss its different strain in brief.
Ans. On the basis of locomotary organ Trypanosoma is included under flagellated protozoans. It resembles Protista on the basis of following characters

(i) Possess unicellularity.
(ii) Possess asexual reproduction, i.e., by binary fission.
(iii) Possess centrally located nucleus and also contain an prominent nucleus endosome.
(iv) Reserve food material is in the form of granules, such characters possessed by
Trypanosoma made it to be included under kingdom–Protista.

Question. Diatoms are also called as ‘pearls of ocean’, why? What is diatomaceous earth?
Ans. Diatoms and desmids are inducted under chrysophytes, kingdom–Protista. These are the main producers in the ocean. They prepare food not only for themselves but also for the
other life forms in the ocean. This is the reason they are also called as ‘pearls of ocean.
Body of diatoms is covered by siliceous shell known as frustule.
‘Diatomaceous earth’ is the accumulation of large deposits of diatoms that forms a siliceous covering extending for several 100 m formed in billions of years. The material obtained from these deposits is used in polishing and filteration of oils and syrups.

Question.There is a myth that immediately after heavy rains in forest, mushrooms appear in large number and make a very large ring or circle, which may be several metres in diameter. These are called as ‘fairy rings’. Can you explain this myth of fairy rings in biological terms?
Discuss the mycilial structure in Agaricus and its soil borne nature.
Ans. The fruiting bodies in Agaricus known as basidiocarps form a concentric ring like structure from the mycelium present in the soil. These basidiocarps resemble button in shape and develop to form a ring like structure.

This fairy ring structure in Agaricus have reported stimulation of plants productivity. This rings are infact fruiting bodies of this fungus and the diameter of this fairy ring increases
every year due to spread of mycelium.

Long Answer Type Questions :

Question. Make a list of algae and fungi that have commercial value as source of food, chemicals, medicines and fodder.
Ans. Algae
Some 70 species of marine algae are used for food, chemical and medicinal purpose.

Fungi
The role of fungi was established in early history yeast have been used in making of bread and alcohol since, the beginning of cultivation the discovery of penicillin, that marked the beginning of a new approach to microbial diseases in human health.
More recent approaches include the application of hydrophins to surfaces leading to biocompatibility of implants and to emulsion formation improving drug delivery.
Products of fungi in medicine, chemical and food are 

Question. Apart from chlorophyll, algae have several other pigments in their chloroplast. What pigments are found in blue, green, red and brown algae, that are responsible for their characteristic colours?
Ans. All photosynthetic organisms contain one or more organic pigments that are capable of absorbing visible radiations, which will initiate the photochemical reaction of photosynthesis. Three major classes of pigments found in plants and algae are the chlorophylls, the carotenoids and the phycobilins.
Carotenoid and phycobilins are called accessory pigments since, the quanta (packets of light) absorbed by these pigments can be transferred to chlorophyll.
The diversity of light harvesting pigments in alga implies that the common ancestor was primitive and that no close affinity exist between blue, green, red, brown, golden brown and green algae, to use their common names.
The characteristic pigments of different classes are mentioned below

Question. ‘Peat’ is an important source of domestic fuel in several countries. How is ‘peat’ formed in nature?
Ans. Peat is an organic fuel consisting of spongy material formed by the partial decomposition of organic matter, primarily plant material in wetlands such as swamps ferns and mosses.
The development of peat is favoured by warm, moist climatic conditions.
The main producers of peat Sphagnum most occurs in bogs. The accumulation of Sphagnum plant in due course of time lead this plant to get hardened and change into peat.
Peat is used in preparation of ethyl alcohol, peat, tar, ammonia, paraffin, etc. Peat is also used in covering the roots during transportation. This enormous value shown by peat for man kind makes it as an important domestic fuel and economic source for man kind.

Question. Algae are known to reproduce asexually by variety of spores under different environmental conditions. Name these spores and the conditions under which they are produced.
Asexual reproduction in algae is very common mean of reproduction.
Ans. Algae and their spores exhibit enormous diversity and they vary greatly in their level of specialisation. Asexual reproduction by spores and their types are described below
(a) By Zoospores These are mobile flagellated spores. In which protoplasm of each vegetative cell undergoes repeated longitudnal division either into 2 or 4 rarely 8 or 16
daughter protoplast. The parent cell loses its flagella, before the onset of division.
After the last series of division, each daughter protoplast secretes a cell wall and neuromotor apparatus that develops two flagella, eyespots and contractile vacuoles.
Thus, each of the daughter cell formed resembles the parent cell in all aspects except the small size.
Formation of zoospores is very common under favourable conditions.

(b) By Aplanospores These are the non-motile spores. They are asexually formed with in a cell, in this the protoplast withdraws itself from the parent wall, rounds up and develops into aplanospores which may either germinate directly or may divide to produce zoospores.

(c) In this, the protoplasm withdraws from the cell wall, rounds up an develop a thick wall under unfavourable condition. These resting spores are called as hypnospores. They are red in colour due to presence of haematochrome.
e.g., Vaucheria, Ulothrix.
(d) Akinetes These are special vegetative thick walled cells present in the filaments which remain under dorment state and return to germination under favourable condition and can also with stand unfavourable condition as Spirogyra.
(e) Statospores This are thick walled spores produced in diatoms.
(f) Neutral Spores In some algae, the protoplast, of vegetative cells directly functions as spores called as neutral spores (e.g., Ectocarpus).

Question. Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify, the statement taking any two examples.
Discuss the changes made in studying biological classification from time to time and also enumerate the need for this changes.
Ans. Classification has been a center piece of biology ever since Linnaeus, providing a frame work on which existing knowledge can be organised and predictions about unknown traits can be made.
But the basis of biological classification has gone through a series of upheavals over the last 3 centuries, from being considered a plan in mind of the creator, to the neutral assessment of over all similarity, to a reflection of evolutionary niches and finally to a phylogenetic mapping of the tree of life. e.g., in two kingdom classification their are two groups, i.e., Plantae and Animalia.

These groups are made on the basis of structural and cellular difference like plant possess cell wall, central vacuole, whereas animals lack cell wall and central vacuole but the drawback in this system classification is that eukaryotic and prokaryotic organisms like Euglena, bacteria and fungi are not included in this kingdom classification.
That are later added in three kingdom classification that in (kingdom–Protista) finally 1969, Whittaker purposed five kingdom classification.

These classifications are done on the basis of increase in understanding regarding organism by the advancements made in scientific techniques and by observing minute detailing that has led this classification more detailed and scientifically correct.