NCERT Exemplar Class 11 Biology Solutions Chapter 2 Biological Classification

Detailed Answers to the Biological Classification Class 11 NCERT Exemplar (Multiple Choice Questions)

MCQs are a great way to test knowledge and improve accuracy. Here, detailed answers for the NCERT Exemplar Class 11 Biology Chapter 2 are provided. Practising these helps in clarifying important concepts.

Question:1

All eukaryotic unicellular organisms belong to
a) Monera
b) Protista
c) Fungi
d) Bacteria

Answer:

The answer is option (b) Protista.
Explanation: All eukaryotic unicellular organisms belong to Protista. This is because Monera consists of prokaryotic organisms, and bacteria fall under the category of Monera, whereas Fungi consists of both unicellular as well as multicellular organisms.

Question:2

The five-kingdom classification was proposed by
a) R.H. Whittaker
b) C. Linnaeus
c) A. Roxberg
d) Virchow

Answer:

The answer is the option (a) R.H. Whittaker.
Explanation: In 1959, R.H. Whittaker proposed the five-kingdom theory.

Question:3

Organisms living in salty areas are called as
a) Methanogens
b) Halophiles
c) Heliophytes
d) Thermoacidophiles

Answer:

The answer is option (b) Halophiles.

Explanation: Halophiles are organisms living in salty areas. Halos refers to salt, whereas phile refers to living.

Question:4

Naked cytoplasm, multinucleated, and saprophytic are the characteristics of
a) Monera
b) Protista
c) Fungi
d) Slime moulds

Answer:

The answer is option (d) Slime moulds
Explanation: Slime moulds contain the above-mentioned characteristics. They were initially classified as fungi, but since they are multinucleated and have a naked protoplasm, they are now classified under protista.

Question:5

An association between the roots of higher plants and fungi is called
a) Lichen
b) Fern
c) Mycorrhiza
d) BGA

Answer:

The answer is option (c).
Explanation: It is called Mycorrhiza. The association between fungi and algae is a lichen; ferns are categorised as Pteridophyta, and BGA is the abbreviation of Blue-Green Algae.

Question:6

A dikaryon is formed when
a) Meiosis is arrested
b) The two haploid cells do not fuse immediately
c) Cytoplasm does not fuse
d) None of the above

Answer:

The answer is option (b). The two haploid cells do not fuse immediately

Explanation: A dikaryon is formed when the two haploid cells do not fuse immediately.

Question:7

Contagium vivum fluidum was proposed by

1. D. J Ivanowsky

2. M.W. Beijerinek

3. Stanley

4. Robert Hook

Answer:

The answer is option (b) M.W. Beijerinek.
Explanation: M. W Beijerinck proposed the contagium vivum fluidum. This term refers to an infectious living fluid.

Question:8

Associations between Mycobiont and Phycobiont are found in
a) Mycorrhiza
b) Root
c) Lichens
d) BGA

Answer:

The answer is option (c) Lichens.
Explanation: The mycobiont, i.e., the fungal element and the Phycobiont, i.e., the algal element, are found in lichens.

Question:9

The difference between a Virus and a Viroid is
a) Absence of protein coat in viroid but present in the virus
b) Presence of low molecular weight RNA in the virus but absent in the viroid
c) Both a and b
d) None of the above

Answer:

The answer is option (a) Absence of protein coat in viroid but present in virus.
Explanation: The difference between the virus and the viroid is the absence of a protein coat in the viroid, but its presence in the virus.

Question:10

With respect to the fungal sexual cycle, choose the correct sequence of events
a) Karyogamy, plasmogamy, meiosis
b) Meiosis, plasmogamy, karyogamy
c) Plasmogamy, karyogamy, and Meiosis
d) Meiosis, karyogamy, plasmogamy

Answer:

The answer is option (c): Plasmogamy, karyogamy, meiosis

Explanation: The correct order is plasmogamy, karyogamy and meiosis

Question:11

Viruses are non-cellular organisms, but replicate themselves once they infect the host cell. To which of the following kingdoms do viruses belong
a) Monera
b) Protista
c) Fungi
d) None of the above

Answer:

The correct answer is option (d) none of the above.
Explanation: This is because viruses are considered to be living as well as non-living and therefore are not classified under any particular kingdom.

Question:12

Members of Phycomycetes are found in
i) Aquatic habitats
ii) On decaying wood
iii) Moist and damp places
iv) As obligate parasites on plants

Choose from the following options

a) None of the above
b) (i) and (iv)
c) (ii) and (iii)
d) All of the above

Answer:

The answer is option (d) All of the above.
Explanation: Phycomycetes are found to be living in aquatic habitats in Moist and damp places, as obligate parasites and on decaying wood as well.

Get Answers to NCERT Exemplar Class 11 Biology Solutions Chapter 2 (Very Short Answer)

Practising questions helps strengthen understanding and problem-solving skills. Given below are a few very short questions with their answers. It helps students to know how to present answers in an exam in the correct form.

Question:1

What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?

Answer:

Several cyanobacteria species are known to carry out nitrogen fixation in soil. Therefore, they are utilised in agricultural fields to improve crops.

Question:2

Suppose you accidentally find an old, preserved, permanent slide without a label. In your effort to identify it, you place the slide under the 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?

Answer:

All unicellular eukaryotes are classified under the kingdom Protista. Therefore, this organism falls under Protista.

Question:3

How is the five-kingdom classification advantageous over the two-kingdom classification?

Answer:

When there was only a two-kingdom classification, several unrelated organisms were categorised as the same kingdom. The five-kingdom classification is more effective than the two-kingdom system because it separates unrelated organisms into more accurate groups. For example, the bacteria were classified as the plant kingdom initially, but many bacteria are heterotrophic. Now bacteria fall under their kind.

Question:4

Polluted water bodies usually have an extremely high abundance of plants like Nostoc and Oscillatoria. Give reasons.

Answer:
Nutrients are available in abundance in polluted water for these organisms. Therefore, they grow in such conditions and are found in large quantities in polluted water.

Question:5

Are chemosynthetic bacteria autotrophic or heterotrophic?

Answer:

Chemosynthetic bacteria are considered to be autotrophic since they are capable of synthesising their own food. In the process of chemosynthesis, it utilises chemicals as an energy source.

Question:6

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?

Answer:

The well-known term 'pea' is an English term and is termed differently in different languages. It is much more convenient to keep in mind a standard scientific name about innumerable names. Therefore, it is preferable to use scientific, universally accepted names.

Question:7

A virus is considered a living organism and an obligate parasite when inside a host cell. But viruses are not classified along with bacteria or fungi. What are the characteristics of viruses that are similar to non-living objects?

Answer:

Attributes of a virus that are similar to those of non-living objects are -
(a) They have an inert protein coat (capsid) and show no cellular structure outside the host.
(b) No cell organelles are present.

Question:8

In the five-kingdom system of Whittaker, how many kingdoms are eukaryotes?

Answer:

In the five-kingdom system of Whittaker, the following four kingdoms are eukaryotes, namely,
(a) Protista
(b) Fungi
(c) Plantae
(d) Animalia

Learn the Answers to NCERT Exemplar Class 11 Biology Chapter 2 (Short Answer)

Answering questions regularly improves accuracy and concept clarity. Solving the NCERT Exemplar Class 11 Biology Chapter 2 helps students revise important topics efficiently.

Question:1

Diatoms are also called 'pearls of the ocean', why? What is diatomaceous earth?

Answer:

Ans. Diatoms are also known as the pearls of the ocean since they are the main producers in the marine world. Their walls are composed of silica and leave behind a considerable amount of cell deposits in their environment. This substance is known as diatomaceous earth. Diatomaceous earth has a gritty texture and is used in polishing, filtration of oils and syrups.

Question:2

There is a myth that immediately after heavy rains in the forest, mushrooms appear in large numbers and make a very large ring or circle, which may be several metres in diameter. These are called 'Fairy rings'. Can you explain this myth of fairy rings in biological terms?

Answer:

The mushrooms' mycelium draws in nutrients from the soil. When at the centre, there is a lack of nutrients, they increase in diameter and develop a circle-like structure. The ring keeps increasing in diameter over the years. They are known as the fruiting bodies of the fungus. This ring is also known as the Fairy Ring.

Question:3

Neurospora, an ascomycete 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?

Answer:

Neurospora is utilised as a model organism to study the genetics of plants. Many attributes of this organism make it perfect to be used for studies related to genetics. Some of these characteristics are as follows:

• Quick procreation, and therefore is easy to culture

• Requires only minimal media

• Easy to manipulate genetically

Question:4

Cyanobacteria and heterotrophic bacteria have been clubbed together in the Eubacteria of the kingdom Monera, 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?

Answer:

All the prokaryotes are classified under the kingdom Monera. Cyanobacteria, as well as heterotrophic bacteria, fall under prokaryotes and therefore are categorised under the same kingdom. The biggest difference between cyanobacteria and heterotrophic bacteria is nutrition. Therefore, this categorisation is justified.

Question:5

At a stage of their cycle, ascomycete fungi produce the fruiting bodies like a apothecium, a perithecium or a cleistothecium. How are these three types of fruiting bodies different from each other?

Answer:

An ascocarp is the fruiting body of an ascomycete. This can be classified under three categories: apothecium, perithecium, and cleistothecium. Apothecium is shaped like a saucer. Perithecium has the shape of a flask with a pore-like outlet, and cleistothecium is a closed structure with no outlet.

Question:6

What observable features in Trypanosoma would make you classify it under the kingdom Protista?

Answer:

There are a few attributes of Trypanosoma which can be categorised under the kingdom Protista:
- It is Unicellular.
- The nucleus is located at the centre.
- It is asexual.
- Food substances are preserved as granules.

Question:7

Fungi are cosmopolitan. Write the role of fungi in your daily life.

Answer:

The role of fungi in our everyday life is as follows :

- Fungi can lead to the rotting of food materials; for example, you can see them developing on stale bread, fruits, and vegetables.
- Yeast causes fermentation.
- Some life-threatening plant and animal illnesses are the result of fungi.
- Some fungi are useful in the production of antibiotics.

- Decomposition in ecosystems as a positive ecological role

Detailed Answers to NCERT Exemplar Class 11 Biology Solutions Chapter 2 (Long Answer)

Solving long questions improves analytical skills and builds confidence for board and competitive exams. The detailed answers of the NCERT Exemplar Class 11 Biology Chapter 2 are given below:

Question:1

Algae are known to reproduce asexually by a variety of spores under different environmental conditions. Name these spores and the conditions under which they are produced.

Answer:

Algae procreate asexually with the help of various spores in different environmental conditions. These spores and the environmental conditions in which they are produced: -
Type of spore
Zoospores - They have thin walls, are flagellated motile spores as they contain flagella.
They develop in favourable conditions and spread by wind.
Aplanospores - They have thin walls, have non-motile spores, and are equipped with flagella.
They develop in unfavourable conditions.
Hypnospore - The spores are made up of thick cell walls to withstand unfavourable conditions. They develop in unfavourable conditions. Akinetes - They develop from vegetative cells and are known to serve as resting cells. They develop in unfavourable conditions.
Statospores - They resemble akinetes and are found in diatoms. They develop in unfavourable conditions.

Question:2

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?

Answer:

In the chloroplasts of algae, there are other pigments present too other than chlorophyll.

- Chlorophyceae - They are Green algae. Contain Chlorophyll a, and b and are green in colour.
- Phaeophyceae - They are Brown algae. Contain chlorophyll a, c, and Fucoxanthin (an xanthophyll pigment) and are brown.
- Rhodophyceae - They are Red algae. Contain Chlorophyll a, d, and r-phycoerythrin and are Red.

Question:3

Make a list of algae and fungi that have commercial value as a source of food, chemicals, medicines, and fodder.

Answer:

The following are some algae that have commercial importance: -

- Agar (taken from red algae Gelidium and Gracilaria) - Utilised as a culture
medium in the laboratory.
- Algin (taken from brown algae), carrageen (derived from red algae) -
Utilised as a gelling agent in food and medical dressing.
- Biofuels (derived from various types of algae) - Used in the production of
biofuels.
- Fertiliser (derived from various types of algae) - Utilised as a fertiliser in
several countries.
- Food (Taken from several species of Porphyra, Laminaria, and Sargassum) -
These marine algae are consumed as food items. This occurs more in the
East Asian nations.
- Single-cell protein (Taken from Chlorella and Spirulina) - Many algae
have high quantities of protein and are utilised as food supplements.

The following are some fungi of commercial importance: -
- Medicine - Penicillium notatum is a fungus used for developing antibiotics of the penicillin group.
- Diseases - Several fungi are known to cause illnesses in both animals and plants.
- Food processing - Yeast for centuries now has been used for fermentation. Alcoholic beverages and bakery items are produced due to the fermentation caused by yeast.
- Food - Different variations of Agaricus are consumed as food in several countries.
- Ripening of cheese - Different variations of fungi are utilised to ripen cheese.
- Spoilage of food - Rhizopus, the mould usually found on stale bread, is known to ruin many food items. For example, as found in stale bread, fruits and vegetables.

Question:4

'Peat' is an important source of domestic fuel in several countries. How is 'peat' formed in nature?

Answer:

Partially decayed and degenerated vegetation and organic matter accumulate to form peat. When plant substances present in generally wet areas do not decay completely due to acidic and anaerobic environmental conditions, it leads to the formation of peat. This wetland vegetation is the main component of peat. The main producer of peat is Sphagnum. However, several other plants may also be included in the formation of peat. Most of the modern peat was formed in high latitudes when the glaciers retreated during the ice age.

This phenomenon took place around 12,000 years ago. Peat accumulates at a terribly slow rate of around 1 millimetre a year. Peat proves to be a major source of domestic fuel in several countries, like Europe and America. It is also valuable in improving the fertility of the soil.

Question:5

Biological classification is a dynamic and ever-evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement by taking any two examples.

Answer:

This is true that biological classification is a dynamic and ever-evolving phenomenon which keeps changing our understanding of life forms.

Biological classification is forever changing. Initially, living beings were only categorised as animals and plants. This was based on the morphological attributes. Then scientists figured out certain misleading information in the categorisation method and came up with better classifications. The five-kingdom theory is the most universally accepted in today's world.

This theory by Whittaker classifies living beings based on structural organisation and phylogenetic relationship. According to this theory, all prokaryotes are classified under one kingdom, i.e. Monera. Eukaryotes are classified into four kingdoms. All the photosynthetic autotrophs are categorised under the plant kingdom, and all the eukaryotic heterotrophs (without a cell wall) are classified as the animal kingdom. However, there are limitations in even this method of categorisation.
For example, the chemosynthetic autotrophs are classified under the kingdom Protista. Lately, some scientists have also claimed that there should be three domains of life, and some have even proposed a Six-Kingdom categorisation.

Also, read the NCERT Solution subject-wise

• NCERT Solutions for Class 11 Maths

• NCERT Solutions for Class 11 Physics

• NCERT Solutions for Class 11 Chemistry

• NCERT Solutions for Class 11 Biology

Important Topics of Biological Classification Class 11 NCERT Exemplar

Some of the important topics are given below from this chapter. Students by solving the Biological Classification Class 11 NCERT Exemplar, can understand all these topics very well.

1- Early Classification Systems

2- Two-Kingdom System (Plantae and Animalia)

3- Five-Kingdom System (Monera, Protista, Fungi, Plantae, Animalia)

4- Kingdom Monera

5- Kingdom Protista

6- Kingdom Fungi -

• Phycomycetes

• Ascomycetes

• Basidiomycetes

• Deuteromycetes

7- Kingdom Plantae

8- Kingdom Animalia

9- Viruses and Viroids

Also, check the NCERT Books and the NCERT Syllabus here

• NCERT Books Class 11 Biology

• NCERT Syllabus Class 11 Biology

• NCERT Books Class 11

• NCERT Syllabus Class 11

Approach to Solve NCERT Exemplar Class 11 Biology Solutions Chapter 2

Start by reading the chapter carefully in order to know about the need for biological classification. Understand the five-kingdom system and its parameters, like cell structure, organisation of the body. Some of the best tips to solve the questions are given below:

1. Read about the distinguishing characteristics and examples of kingdoms (Monera, Protista, Fungi, Plantae, and Animalia).

2. Pay attention to key definitions, typical features, and group differences. Students can use tables and flowcharts to arrange information for speedy revision.

3. Practice all forms of exemplar questions given in the NCERT Exemplar Class 11 Biology Solutions Chapter 2.

4. Regularly revise key concepts to increase retention and improve exam scores.

Must Read NCERT Notes subject-wise

• NCERT Notes for Class 11 Maths

• NCERT Notes for Class 11 Physics

• NCERT Notes for Class 11 Chemistry

• NCERT Notes for Class 11 Biology

Important Question from Biological Classification Class 11 NCERT Exemplar

Given below is a question from the Biological Classification chapter. For more such questions, students can refer to the NCERT Exemplar Class 11 Biology Chapter 2.

Question:

Which of the following organisms can be found in extreme saline conditions?

a) Eubacteria

b) Archaebacteria

c) Cyanobacteria

d) Mycobacteria

Answer: b) Archaebacteria

Explanation:

Archaea are a unique group of prokaryotic microorganisms that can survive in extreme environments, including highly saline conditions such as salt lakes and salt mines. This is due to their specialised cell membrane and enzyme systems that allow them to thrive where most other organisms cannot. In contrast, eubacteria, cyanobacteria, and mycobacteria are generally not adapted to such extreme salinity. The ability of archaea to live in harsh environments is a key reason for their classification as a separate group within the five-kingdom system of biological classification

NCERT Exemplar Class 11 Solutions

• NCERT Exemplar Class 11 Mathematics Solutions
• NCERT Exemplar Class 11 Chemistry Solutions
• NCERT Exemplar Class 11 Physics Solutions

NCERT Exemplar Class 11 Biology Solutions Chapter Wise

The biology chapter-wise exemplar solutions of Class 11 are given below: