NCERT Exemplar Solutions for Class 11 Biology Chapter 1 The Living World
These Solutions are part of NCERT Exemplar Solutions for Class 11 Biology. Here we have given NCERT Exemplar Solutions for Class 11 Biology Chapter 1 The Living World.
VERY SHORT ANSWER QUESTIONS
Question 1.
Couplet in taxonomic key means……. .
Solution:
Couplet in taxonomic key is a pair of a contrasting characters used as tool foi” identification to aid in identification of a newly discovered organism.
Question 2.
What is a monograph?
Solution:
Monograph is a specialised work of documenting information on a particular taxon, /. e., family or genus or on aspect of subject, usually by a single author.
The main purpose of monograph is to present primary research and original work.
Question 3.
Amoeba multiplies by mitotic cell division. Is this phenomena growth or reproduction? Explain.
Solution:
Amoeba multiplies by simple mitotic cell divisions giving rise to two daughter Amoebae. Growth here is synchronous with reproduction, i.e., increases in number.
Question 4.
Define metabolism.
Solution:
Metabolism is the sum total of all biological reactions occurring in any living cell, which are controlled absolutely by enzymes. These reactions are of two types breaking down reactions (catabolism, e.g., cell ‘ respiration) and synthesing reactions (anabolism,
e.g., photosynthesis).
Question 5.
Which is the largest botanical garden in world? Name a few well known botanical gardens in India.
Solution:
A botanical garden is dedicated to collection, cultivation and display of wide range of plants labelled with their botanical names.
The largest botanical garden in the world is Royal Botanical Garden (in Kew, London). In India the famous well known botanical gardens are
(i) National Botanical Garden (NBG) Lucknow, UP.
(ii) Botanical Garden of FRI, Dehradun (UK).
(iii) Lloyd Botanical Garden, Daijeeling.
(iv) Indian Botanical Garden, Sibpur, Kolkata.
SHORT ANSWER QUESTIONS
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?
Solution:
- Living organisms, grow, have metabolism and respond to external stimuli and reproduce as well. These characteristics are not shown by non-living objects.
- In biological terms growth is characteristic feature of all living organisms. It relates to increase in size by accumulation of protoplasm in the cell thus resulting in increase in the size of the cell.
- Increase in number of cell by cell division on other hand results in the size of individual organism.
- Snow is an inanimate (non-living) object, while rolling over, it gathers more snow on its surface thus, it increases in size by physical phenomenon but not by biological phenomenon.
- This growth cannot be thus compared to that seen in living organisms.
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.
Solution:
There are existing 20 plant species and 20 animal species in the given habitat. They will exhibit the biodiversity in that given habitat because diversity refers to variation in a broad term and can be applied to any area whereas biodiversity is a degree of variation of life forms within a specified area.
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.
Solution:
ICBN has specified certain rules and principles in order to facilitate the study of plants by botanists. It helps in correct positioning of any organism newly discovered through the pressure of proper identification and nomenclature.
The taxonomic hierarchy, which is used while
classifying any plant given below
Kingdom-Plan tae
Division-phyta
Class-ae
Order-ales
Family-eae/ceae
Genus-First name of organism usually Latin word and written in italics.
Species-Second word of scientific name, also written in italics.
Question 4.
What are hormone receptors? What are the modes of their action ?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?
Solution:
These morphological variants are called bio types. It includes group of genetically similar plants showing similarity when grown in same environmental and geographical regions. The same environment provides them the similar abiotic factors like soil, pH, temperature, etc.
When growth in two different geographical regions, they are exposed to different abiotic characters which affects their growth, and development bringing changes in their external morphological features but, their genetic constitution remain same.
Question 5.
What is the difference between flora, fauna and vegetation? Eichhornia crassipes is called as an exotic species, while Rauwoljia serpentina is an endemic species in India. What do these terms exotic and endemic refer to?
Solution:
Following are the difference between flora, fauna and vegetation
Question 6.
Brinjal and potato belong to the same genus Solamim, but to two different species. What defines them as seperate species?
Solution:
Genus is a taxonomic rank used in bionorr.’al nomenclature comprising of a group of related species sharing few common characters.
Solanum is the largest genus of flowering plants which includes few economically important plants, e.g., potato, tomato, tobacco and brinjal. All these plants show some common morphological structures related to vegetative and reproductive similarities. So, they are are included in the same common genus Solanum.
Question 7.
The number and kinds of organism is not constant. How do you explain this statement? Change is law of nature.
Solution:
The number and kind of organisms is not constant, because of the following reasons new organism are added due to mechanisms of.
(i) sexual reproduction
(ii) mutation
(iii) evolution
The number of organisms get reduced due to
(i) environmental threats
(ii) loss of habitat
(iii) anthropogenic activities
LONG ANSWER QUESTIONS
Question 1.
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?
Solution:
Brassica campestris Linn
(a) The common name of Brassica compestris Linn is mustard.
(b) The first part of the name denotes the genetic name and the second part is the species name of the plant.
(c) According to ICBN, all scientific names are comprised of one genetic name followed by a species name, which require to be always written in italics. It is a rule of bionomial nomenclature.
(d) Linn means Linnaeus. He was the first to discover the plant. He identified, named and classified the plant, so the plant is named after him by adding suffix ‘Linn’, after the scientific name B. campestris.
Question 2.
What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?
Solution:
The aids which help in identification, classification and naming of a newly discovered organisms (plant or animal) the taxonomic aids.
It could be in the form of a preserved document like herbaria or specimen kept at museums or scientific institutions. Other aids include written document like monography, taxonomic keys, couplets, etc.
A new organism found can be studied while comparing it with living plants and animals living in protected areas like Botanical gardens, Zoological parks, etc. Botanical gardens helps in conservation of plants by
(i) Plant species growing important local and keeping record of them.
(ii) Growing and maintaining species that rare are and endangered.
(iii) Supplying seeds for different aspects of botanical research.
Zoological parks contribute in conserving biodiversity by
(i) Providing natural environment and open space to animals.
(ii) Providing home to different native and exotic wild animals.
(iii) Rescue of endangered species.
(iv) Facilitating breeding animal and releasing them free. Thus, both botanical gardens and zoological parks play an important role in conservation of biodiversity.
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