NCERT Exemplars - The Living World (Part-1) NEET Notes | EduRev

Multiple Choice Questions

Q.1. As we go from species to kingdom in a taxonomic hierarchy, the number of common characteristics
(a) Will decrease
(b) Will increase
(c) Remain the same
(d) May increase or decrease
Ans. (a)
Solution: 

• As we go higher from species to the kingdom, the number of common characteristics goes on decreasing. 
• The lower the taxa, the more are the characteristics that the members within the taxon share. 
• The higher the category, the greater is the difficulty of determining the relationship to other taxa at the same level.

Classification of living things

Q.2. Which of the following ‘suffixes’ used for units of classification in plants indicates a taxonomic category of 'family’?
(a) —Ales
(b) —Onae
(c) —Aceae
(d) —Ae
Ans. (c)
Solution: 
(a) —Ales —> Order (plant)
(b) —Onae —> Class (plant)
(c) —Aceae —> Family (plant)
(d) —Ae —> Phylum (plant)

Q.3. The term ‘systematics’ refers to
(a) Identification and study of organ systems of plants and animals
(b) Identification and preservation of plants and animals
(c) Diversity of kinds of organisms and their relationship
(d) Study of habitats of organisms and their classification
Ans. (c)
Solution: 

• Human beings were, for long, interested in knowing more about different kinds of organisms and their diversities and the relationships among them. This branch of study was referred to as systematics. 
• Systematics takes into account evolutionary relationships between organisms.
  
  

Q.4. Genus represents
(a) An individual plant or animal
(b) A collection of plants or animals
(c) A group of closely related species of plants or animals
(d) None of these
Ans. (c)
Solution: Genus comprises a group of related species with more common characteristics than species of other genera.

Q.5. The taxonomic unit ‘Phylum’ in the classification of animals is equivalent to which hierarchical level in the classification of plants?
(a) Class
(b) Order
(c) Division
(d) Family
Ans. (c)
Solution: 

• Classes comprising animals like fishes, amphibians, reptiles, birds, and mammals constitute the next higher category called Phylum. All these classes are included in the phylum Chordata. 
• In plants' case, classes with a few similar characters are assigned to a higher category called Division.
  
  

Q.6. Botanical gardens and zoological parks have
(a) Collection of endemic living species only
(b) Collection of exotic living species only
(c) Collection of endemic and exotic living species
(d) Collection of only local plants and animals
Ans. (c)
Solution: 

• Botanical gardens and zoological parks are specialised places where living plants are grown and living animals are kept (where they can reproduce too) respectively. 
• Both, endemic (local), as well as exotic (foreign to that place) species, are kept in these places. 
• They can be used for scientific studies. 
• Botanical garden at Kew, England and National Zoological Park, Delhi are some famous examples.

Botanical GardenQ.7. The taxonomic key is one of the taxonomic tools in the identification and classification of plants and animals. It is used in the preparation of
(a) Monographs
(b) Flora
(c) Both (a) and (b)
(d) None of these
Ans. (c)
Solution: 
(i) Flora contains the actual account of habitat and distribution of plants of a given area. These provide the index to the plant species found in a particular area.
(ii) Manuals are useful in providing information to identify names of species found in an area. Monographs contain information on anyone taxon, i.e. anyone genus or family at a particular time. They also help with incorrect identification.

Q.8. All living organisms are linked to one another because
(a) They have the common genetic material of the same type
(b) They share common genetic material but to varying degrees
(c) All have a common cellular organization
(d) All of the above
Ans. (b) 
Solution: All living organisms - present, past, and future are linked to one another by the sharing of the common genetic material, but to varying degrees.

Q.9. Which of the following is a defining characteristic of living organisms?
(a) Growth
(b) Ability to make sound
(c) Reproduction
(d) Response to external stimuli
Ans. (d)
Solution:

• Growth is not observed in some living organisms.
• Ability to make sound is also not observed in lower animals.
• Many living organisms are unable to reproduce. Therefore, growth and ability to make sound and reproduction are not considered defining characteristics of living organisms.
• Response to external stimuli or the environment in which an organism’s lives is the most important characteristic of any living organism. Every organism shows a response to its surrounding environment.

Q.10. Match the following and choose the correct option.

(a) D—(i), C—(ii), E—(iii), B—(iv), A-(v)
(b) E—(i), D—(ii), B—(iii), A—(iv), C-(v)
(c) D—(C), E—(ii), B—(iii), A—(iv), C-(v)
(d) E—(i), C—(ii), B—(iii), A—(iv), D-(v) 
Ans. (a)
Solution: 

Q.1. Linnaeus is considered as Father of Taxonomy. Name two other botanists known for their contribution to the field of plant taxonomy?
Ans. The natural system of classification for flowering plants was given by George Bentham and Joseph Dalton Hooker, in a three-volume of Genera Plantarum.

Q.2. What does ICZN stand for?
Ans. ICZN stands for International Code of Zoological Nomenclature.

Q.3. Couplet in taxonomic key means _____
Ans. The keys are based on the contrasting characters generally in a pair called a couplet. It represents the choice made between two opposite options. This results in the acceptance of only one and the rejection of the other.

Q.4. What is Monograph?
Ans. Monographs contain information on anyone taxon, i.e. anyone genus or family at a particular time.Q.5. Amoeba multiplies by mitotic cell division. Is this phenomenon growth or reproduction? Explain.
Ans. Amoeba is a unicellular organism. It undergoes division and gives rise to two Amoeba. Therefore, in unicellular organisms, cell division is the same as reproduction. It is a form of asexual reproduction called binary fission.

Q.6. Define Metabolism.
Ans. Metabolism refers to a series of chemical reactions that occur in a living organism to sustain life.

Q.7. Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Ans. 

• The largest famous botanical garden globally is Royal Botanical Garden, Kew (London), England. 
• India's largest botanical garden is Indian Botanical Garden, Sibpur, Howrah, Kolkata, West Bengal. National Botanical Research Institute is situated at Lucknow (India).
  
  

Q.1. A ball of snow when rolled over snow increases in mass, volume, and size. Is this comparable to growth as seen in living organisms? Why?
Ans. No, this is not comparable to growth as seen in living organisms. Non-living objects like snowball also grow if we increase body mass as a criterion for growth. However, this kind of growth exhibited by non-living objects is by accumulating material on the surface (accretion). In living organisms, growth is from the inside.

Q.2. In a given habitat we have 20 plant species and 20 animal species. Should we call this ‘diversity’ or ‘biodiversity’? Justify your answer.
Ans. In a given habitat we have 20 plant species and 20 animal species. We can call this ‘biodiversity’. Because “bio” refers to living and diversity means “variation or variety”. Each different kind of plant, animal, or organism that we see represents a species. This refers to biodiversity or the number and types of organisms present on earth.

Q.3. International Code of Botanical nomenclature (ICBN) has provided a code for the classification of plants. Give hierarchy of units of classification botanists follow while classifying plants and mention different ‘Suffixes’ used for the units.
Ans.

Q.4. A plant species shows several morphological variations in response to the altitudinal gradient. When grown under similar growth conditions, the morphological variations disappear, and all the variants have common morphology. What are these variants called?
Ans. 

• These variants are called biotypes. All biotypes are similar genetically, but they are different morphologically. 
• The morphological difference happens because of the differences in abiotic factors like temperature, pH of the soil, climate, etc. 
• The difference in abiotic factors is the result of different altitudinal gradients.
  
  

Q.5. How do you prepare your own Herbarium sheets? What are the different tools you carry with you while collecting plants for the preparation of a herbarium? What information should a preserved plant material on the herbarium sheet provide for taxonomical studies?
Ans. Following are the various steps of preparing a herbarium:

• Different tools that need to be carried while collecting plants for the preparation of a herbarium are; digger and pruning knife, sickle, vasculum, polythene bags, old newspaper or magazine, blotting paper, plant press, field notebooks, herbarium sheets, glue, labels, etc.
• The preserved material should have thorough information and classification. This should include the names of division, order, family, genus, and species.

Q.6. What is the difference between flora, fauna, and vegetation? Eichhornia crassipes is called an exotic species while Rauwolfia serpentina is an endemic species in India. What do these terms exotic and endemic refer to?
Ans. The sum of plant species in a given geographical area is called the flora of that area. The sum of animal species in a given geographical area is called the fauna of that area. The term ‘vegetation’ has a wider scope than the term ‘flora’. Vegetation is often used for a much wider geographical area than a particular ecosystem. In many cases, the term ‘vegetation’ is used for all the plants globally.

• Endemic Species: A species found only in a particular geographical area is called the endemic species.
  Example: Rauvolfia serpentine is found only in India. So, it is an endemic species in India.
• Exotic Species: A species that is not naturally found in a particular area but maybe living because of careful selection and breeding or because of being imported is called an exotic species.
  Example: Eichhornia crassipes is native to another country, but it was introduced in India. So, it is an exotic species in India.

Q.7. A plant may have different names in different regions of the country or world. How do botanists solve this problem?
Ans. 

• There are many languages and even more, dialects being spoken in different parts of the world. This means a plant may have different names in different regions of the country or world. This compounds the problem for anybody because nobody can remember all those names. 
• To solve this problem, botanists have devised a binomial nomenclature system so that a particular species can have a unique name for scientific study. 
• A botanical name is usually composed of two terms, viz. genus name and species name. Care is taken to make a unique name for a particular species.

Q.8. Brinjal and potato belong to the same genus Solarium, but to two different species. What defines them as separate species?
Ans. “Species is a group of potentially interbreeding groups that are reproductively isolated from other such groups”. Brinjal and potato belong to the same genus Solarium, but to two different species as they are reproductively isolated.

Q.9. Properties of cell organelles are not always found in the molecular constituents of cell organelles. Justify.
Ans. 

• All living phenomena are due to underlying interactions. Properties of tissues are not present in the constituent cells. Similarly, properties of cellular organelles are not present in the molecular constituents of the organelle but arise as a result of interactions among the molecular components comprising the organelle. 
• These interactions result in emergent properties at a higher level of organization. This phenomenon is true in the hierarchy of organizational complexity at all levels.
  
  

Q.10. The number and kinds of an organism are not constant. How do you explain this statement?
Ans. 

• The number and kinds of organisms vary according to the seasonal changes like the population of certain insects increases during the rainy season. 
• The IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrates, 359 invertebrates, and 87 plants) in the last 500 years and evolution leads to new species. 
• The number of species keeps on increasing or decreasing due to extinction, evolution, and seasonal changes.