NCERT Solutions for Class 11 Science Biology Chapter 1 The Living World are provided here with simple step-by-step explanations. These solutions for The Living World are extremely popular among Class 11 Science students for Biology The Living World Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the NCERT Book of Class 11 Science Biology Chapter 1 are provided here for you for free. You will also love the ad-free experience on Meritnation’s NCERT Solutions. All NCERT Solutions for class Class 11 Science Biology are prepared by experts and are 100% accurate.
Page No 1:
Question 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 same
d. May increase or decrease
Answer:
As we go from species to kingdom in a taxonomic hierarchy, the number of common characteristics will decrease. Organisms of the same species are more closely related (they have more common characteristics) as compared to various organisms belonging to the same kingdom.
Hence, the correct answer is Option a.
Page No 1:
Question 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
Answer:
Suffix "Aceae" is used for a taxonomic category of family in the system of classification in plants.
Hence, the correct answer is option c.
Page No 1:
Question 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
Answer:
The term ‘systematics’ comes from the Latin word "systema" meaning the systematic arrangement of organisms. It refers to the diversity of organisms along with their relationship.
Hence, the correct answer is option c.
Page No 1:
Question 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
Answer:
Genus represents a group of closely related species of plants or animals. The genus comprises a group of species that have more in common with each other as compared to the species of other genera.
Hence, the correct answer is option c.
Page No 1:
Question 5:
The taxonomic unit ‘Phylum’ in the classification of animals is equivalent to which hierarchical level in classification of plants
a. Class
b. Order
c. Division
d. Family
Answer:
Hence, the correct answer is option c.
Page No 2:
Question 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
Answer:
Botanical gardens and zoological parks have a collection of endemic and exotic living species. They serve as very important taxonomical aids.
Hence, the correct answer is option c.
Page No 2:
Question 7:
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 & b
d. None of these
Answer:
Hence, the correct answer is option c.
Page No 2:
Question 8:
All living organisms are linked to one another because
a. They have common genetic material of the same type
b. They share common genetic material but to varying degrees
c. All have common cellular organization
d. All of above
Answer:
All living organisms are linked to one another by sharing common genetic material but to a varying degree. The living organisms are self-replicating, evolving, and self-regulating interactive systems capable of responding to external stimuli.
Hence, the correct answer is option b.
Page No 2:
Question 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
Answer:
The defining characteristic of living organisms is their ability to respond to external stimuli.
Hence, the correct answer is option d.
Page No 2:
Question 10:
Match the following and choose the correct option:
| Column I | Column II |
| A. Family | i. tuberosum |
| B. Kingdom | ii. Polymoniales |
| C. Order | iii. Solanum |
| D. Species | iv. Plantae |
| E. Genus | v. Solanacea |
a. A-v, B-iv, C-ii, D-i, E-iii
b. A-iv, B-iii, C-v, D-ii, E-i
c. A-iv, B-iii, C-v, D-i, E-ii
d. A-iv, B-iii, C-ii, D-v, E-i
Answer:
| Column I | Column II |
| A. Family | v. Solanacea |
| B. Kingdom | iv. Plantae |
| C. Order | ii. Polymoniales |
| D. Species | i. tuberosum |
| E. Genus | iii. Solanum |
Hence, the correct answer is option a.
Page No 3:
Question 1:
Linnaeus is considered as Father of Taxonomy. Name two other botanists known for their contribution to the field of plant taxonomy?
Answer:
Page No 3:
Question 2:
What does ICZN stand for?
Answer:
ICZN stands for International Code for Zoological Nomenclature.
Page No 3:
Question 3:
Couplet in taxonomic key means ________________ .
Answer:
A couplet in a taxonomic key is a pair of contrasting characters. Out of the two, one is accepted and the other is rejected. These are analytical statements used in the identification of taxonomic order.
Page No 3:
Question 4:
What is a Monograph?
Answer:
Ans. Monographs are a means of recording descriptions. They contain information on any one taxon.
Page No 3:
Question 5:
Amoeba multiplies by mitotic cell division. Is this phenomena growth or reproduction? Explain.
Answer:
Ans. In case of unicellular organisms such as Amoeba, reproduction is synonymous with growth i.e increase in number of cells.
Page No 3:
Question 6:
Define metabolism.
Answer:
Ans. Metabolism is the sum total of all reactions taking place in a living organism that involves breaking, changing, making of biomolecules into and from other biomolecules. All living organisms are made up of chemicals, these chemicals take part in different reactions in order to fulfill various physiological processes going on in an organism.
Page No 3:
Question 7:
Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Answer:
Ans. largest botanical garden in the world is Royal Botanical Garden , Kew (London).
Indian Botanical Garden, Howrah and National Botanical Research Institute, Lucknow are well known in India.
Page No 3:
Question 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?
Answer:
A ball of snow is a non living thing, when rolled over snow would increase in size by addition of substance on the surface. This is not comparable to growth seen in living organisms as the growth in them is from inside.
Page No 3:
Question 2:
In a given habitat we have 20 plant species and 20 animal species. Should we call this as ‘diversity’ or ‘biodiversity’? Justify your answer.
Answer:
Ans. As there is a variety of plant and animal species present, we would call this biodiversity. Each plant and animal that we see could represent a different species. This represents biodiversity- different types of organisms present on earth.
Page No 3:
Question 3:
International Code of Botanical Nomenclature (ICBN) has provided a code for classification of plants. Give hierarchy of units of classification botanists follow while classifying plants and mention different ‘Suffixes’ used for the units.
Answer:
| Taxon | Suffix |
| Kingdom | No definite suffix |
| Division | phyta/spermae |
| Class | nae/opsida |
| Order | ales |
| Family | aceae |
| Genus | No definite suffix |
| Species | No definite suffix |
Page No 3:
Question 4:
A plant species shows several morphological variations in response to altitudinal gradient. When grown under similar conditions of growth, the morphological variations disappear and all the variants have common morphology. What are these variants called?
Answer:
A plant species that show morphological variations in response to altitudinal gradient are called ecotypes. The population of such plant species when are subjected to climatic and other edaphic variations undergoes genetic modifications in order to adapt to their respective environment. These plant populations can interbreed among themselves. They are capable of attaining the same morphological forms when provided with similar conditions.
Page No 4:
Question 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?
Answer:
Preparing Herbarium sheets require two major steps :
1. Collection of samples
2. Mounting
The detailed procedure is as follows :
1. An area is selected for excursion, plant sample such as root, leaves, stem, whole plant etc is collected using various tools.
2. These samples are kept in a vasculum to prevent the material from wilting.
3. The samples are spread over newspapers or magazine sheets and put in a plant press.
4. The sheets are changed in 24 hrs and the procedure continues for a couple of days until the sample is dry.
5. The completely dried samples are pasted on herbarium sheets labelled properly.
Tools used in collecting plant samples: digger, prunning knife, sickel, vasculum, polythene bag, field notebook, herbarium sheets, labels, plant press etc.
Information on herbarium sheets : plant size, branching, root system, specialized underground organ, topography and date of collection.
Page No 4:
Question 6:
What is the difference between flora, fauna and vegetation? Eichhornia crassipes is called as an exotic species while Rauwolfia serpentina is an endemic species in India. What do these terms exotic and endemic refer to?
Answer:
| Flora | Fauna | Vegetation |
| It refers to the plant species present in a particular geographical location at a given time. |
It refers to the animals found in a particular area. | It is a broader category used to describe the overall categories of plants present in an area. |
Exotic species : Species occurring at any other place apart from its native place is said to be exotic.
Endemic species : Species found only at a particular place/area is said to be endemic species.
Page No 4:
Question 7:
A plant may have different names in different regions of the country or world. How do botanists solve this problem?
Answer:
In order to invent a universal code for identifying same plant in different parts of the world, botanists have set International Code for Binomial Nomenclature (ICBN), wherein each plant is given a unique name comprising or two parts- generic name and specific epithet.
eg. Mango has the name "Magnifera indica".
ICBN makes sure that same name is not used for two organisms.
Page No 4:
Question 8:
Brinjal and potato belong to the same genus Solanum, but to two different species. What defines them as seperate species?
Answer:
Species can be defined as an interbreeding group kept at reproductive isolation from other such similar groups.
Brinjal and potato belong to the same genus Solanum, but to two different species because :
1. They have some morphological difference such potato grows underground whereas brinjal is areal.
2. Reproductive Isolation. They cannot interbreed.
Page No 4:
Question 9:
Properties of cell organelles are not always found in the molecular constituents of cell organelles. Justify.
Answer:
A cell is made up of many organelles and each has its distinctive features. Properties of cell organelles are not always found in the molecular constituents of cell organelles but are the result of various interactions among the molecules present in those organelles. These interactions result into the emergent properties that become the basis of higher organization. This holds true for all hierarchy levels.
Page No 4:
Question 10:
The number and kinds of organism is not constant. How do you explain this statement?
Answer:
The number and kind of organisms is not constant and is ever changing because of various factors such as - season, vegetation, climatic factors, migration, extinction etc. All organisms whether plants or animals are interdependent on each other and on the abiotic factors and are hence vulnerable to change in numbers.
Page No 4:
Question 1:
What is meant by living? Give any four defining features of life forms.
Answer:
The objects exhibiting growth, development, responsiveness, reproduction and other such features of life are termed as 'living beings'.
We can say living organisms are self replicating, evolving, self regulating interactive systems.
Four defining features of living beings are :
1. Growth : All organisms grow. They increase in mass and in number. Plants grow throughout their lives and animals grow up to a certain age. In higher animals and plants, growth and reproduction are mutually exclusive but unicellular organisms grow by cell division.
Non living things may also grow like snow balls, boulders etc but this growth is external. Living things grow from inside.
2. Reproduction : Reproduction refers to production of an offspring of similar kind. Organisms reproduce through different methods. Asexual means include binary fission, fragmentation, vegetative propagation. Sexual reproduction includes specialized reproductive organs.
3. Response to Stimuli: All living things respond to every kind of stimuli experienced by them in the external environment.
4. Homeostasis: Every living organsims tries to maintain its internal environment without much deviation in it unlike the innate matter.
Page No 4:
Question 2:
A scientist has come across a plant which he feels is a new species. How will he go about its identification, classification and nomenclature.
Answer:
Newly discovered plant species needs to be matched with the available sources of information such as - Herbarium, monographs or other preserved plant material. For identification, the scientist needs to study the physiological and anatomical features of the sample, for classification he needs to match the characteristic features with the similar information available in the sources/literature. He can then name it according to the binomial nomenclature system.
Page No 4:
Question 3:
Brassica campestris Linn
a. Give the common name of the plant.
b. What do the first two parts of the name denote?
c. Why are they written in italics?
d. What is the meaning of Linn written at the end of the name?
Answer:
A. Common name : Mustard
B. First part denotes generic name (genus) and second part denotes specific epithet (species).
C. By rule in ICBN, all scientific names are written in italics
D. Linn at the end represents the ' Linnaeus' was the one to have identified, classified and named the plant. As credit, the initials are added to the end of scientific name
Page No 4:
Question 4:
What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?
Answer:
All the stored information, procedures etc that are useful in identification and classification of organisms are called taxonomical aids.
Importance of herbaria and museums:
Herbaria :
1. Helpful in authentic identification of unknown plants
2. Helpful in locating relatives of economically important plants.
3. Serves as a quick referral system for taxonomic studies.
Museum :
Museum help in preserving and prolonging the life of specimens - scientific specimens, works of art etc in their natural forms.
Botanical gardens and Zoological parks are an ex situ form of conservation wherein the plants and animals are preserved outside of their natural environment. Botanical gardens help in growing and maintaining rare and endangered plants. Zoological parks conserve threatened wildlife. It is place where animals are protected and fed. They provide information on different native and exotic mammals, birds, reptiles etc. along with their breeding habits, behavior etc.
Page No 4:
Question 5:
Define a taxon. What is meant by taxonomic hierarchy. Give a flow diagram from the lowest to highest category for a plant and an animal.
What happens to the number of individuals and number of shared characters as we go up the taxonomical hierarchy?
Answer:
A classification unit in taxonomy like Genus, Family, Order, Phyla, Kingdom, etc is termed as taxon (singular).
Taxonomic Hierarchy means that a single large taxon contains within it the sets of various smaller taxa, which in turn may contain multiple taxa within it following the same pattern of having one or more taxa within it.
The Flow diagram from the taxon of lowest rank to highest rank within teh planta and animal kingdom is as following:
Plants:
Species→ Genus → Family → Order → Class → Division → Kingdom
Animals:
Species→ Genus → Family → Order → Class → Phylum → Kingdom
As we move up teh taxonomical heirarchy the number of common characteristics within the taxon keeps on reducing from a taxon of lower rank to teh taxon of higher rank. For example, the taxon "species" has the maximum number of common characteristics and the taxon "kingdom" has the least.
Page No 4:
Question 6:
A student of taxonomy was puzzled when told by his professor to look for a key to identify a plant. He went to his friend to clarify what ‘Key’ the professor was referring to? What would the friend explain to him?
Answer:
For every taxon or taxonomic category seperate keys are used. Thus keys are important and pretty useful in identifying and classifying the specimen under observation.
Page No 5:
Question 7:
Metabolism is a defining feature of all living organisms without exception. Isolated metabolic reactions in vitro are not living things but surely living reactions. Comment.
Answer:
Page No 5:
Question 8:
Do you consider a person in coma-living or dead?
Answer:
Page No 5:
Question 9:
What is the similarity and dissimilarity between “whole moong daal” and “broken moong daal” in terms of respiration and growth? Based on these parameters classify them into living or nonliving?
Answer:
| Whole Moong Dal | Broken Moong Dal |
| Its a whole seed | It is chunk or pieces of the whole seed |
| It's living | It's non-living organic matter |
| It is able to germinate | It does not germinate |
| It respires | It does not exhibit any respiration |
Page No 5:
Question 10:
Some of the properties of tissues are not the constituents of its cells. Give three examples to support the statement.
Answer:
i) Blood: Blood is a connective tissue that helps in maintaining homeostasis including maintaining a steady body temperature, but none of its constituent cell types are involved in maintaining the body temperature and many of the processes involved in maintaing homeostasis.
ii)
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