Question:
What is meant by living? Give any four defining features of life forms.
Answer:
The number and kinds of organism change dramatically as one moves from one place to the next because of the following reasons:
(i) Environmental variability : Climate, food supply and interaction with other organisms affect organisms and causes changes in their number and kind.
(ii) population of reproductively compatible organisms that have similar biological properties, no species can be found everywhere.
(iii) Evolutionary change : Species do not stay the same over time, they are in constant state of change as individuals. They are able to survive and reproduce within certain environments become more frequent, while others less capable die or fail to produce offspring. Sometimes organisms evolved to adapt environment.
(iv) Continental drift : The locations of landmasses across earth’s surface have not remained the same, but have changed slowly over the cause of earth’s history. Therefore, the condition experienced by organisms change over long period of earth’s history. Ecological limitation : Every organism has a limited range of condition that must be met in order to allow it to live and reproduce. Since a species is a
Long Answer Type Questions
1.What is meant by living? Give any four defining features of life forms.
Soln. The objects exhibiting growth, development, responsiveness and other characteristics of life are called as living.
Four defining feature of life forms are as follows:
(i) Consciousness
(ii)Metabolism
(iii)Homeostasis
(iv)Cellular organisation
(i) Consciousness : It is awareness of the surroundings and response to external stimuli. The external stimuli can be physical, chemical or biological. The stimuli are perceived by sense organs in higher animals, e.g., eyes, ears, nose. All organisms, from primitive prokaryotes to most advanced and complex eukaryotes, are able to sense and respond to environmental factors. Organisms also handle chemicals entering their bodies.
(ii)Metabolism : All organisms operate a network of thousands of chemical
reactions. The sum total of all chemical reactions occurring in an organism due to specific interactions amongst different types of molecules within the interior of cells is called metabolism (Gk. metabole — change).
(iii) Homeostasis : A favourable internal environment suitable for the functioning of body organs is present in every living being. It is quite different from the external environment. Changes in external environment do not have much impact on the internal environment as the living beings have a self regulated system to adjust and maintain the internal environment. The phenomenon is called homeostasis (Gk. homois — alike, stasis — standing.
(iv) Cellular organisation : Each living being is a complex entity which is formed of one or more cells. Cells work together to form tissues, tissues form organs, organs form organ systems and various organ system form the complete organism. So, cell is the basic unit of every living organism.
The Living World
Q 1.
Some of the properties of tissues are not the constituents of its cells. Give three examples to support the statement.
Q 2.
What does ICZN stand for?
Q 3.
Match the following and choose the correct option.
| A. |
Family |
(0 |
tuberosum |
| B. |
Kingdom |
(ii) |
Polymoniales |
| C. |
Order |
(iii) |
Solarium |
| D. |
Species |
(iv) |
Plantae |
| E. |
Genus |
(v) |
Solanaceae |
Options:
(a) D—(i), C—(ii), E—(iii), B—(iv), A-(v)
(b) E—(i), D—(ii), B—(iii), A—(iv), C-
(c) D-C), E—(ii), B—(iii), A—(iv), C-(v)
(d) E—(i), €—(ii), B—-(iii), A-(iv), D-(v)
Q 4.
Amoeba multiplies by mitotic cell division. Is this phenomena growth or reproduction? Explain.
Q 5.
A plant may have different names in different regions of the country or world. How do botanists solve this problem?
Q 6.
Amoeba multiplies by mitotic cell division. Is this phenomena growth or reproduction? Explain.
Q 7.
Properties of cell organelles are not always found in the molecular constituents of cell organelles. Justify.
Q 8.
Given below is the scientific name of mango. Identify the correctly written name.
Mangifera Indica Mangifera indica
Q 9.
What is a monograph?
Q 10.
Brassica compestris 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?
Q 11.
What does ICZN stand for?
Q 12.
Why are the classification systems changing every now and then?
Q 13.
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?
Q 14.
Linnaeus is considered as Father of Taxonomy. Name two other botanists known for their contribution to the field of plant taxonomy?
Q 15.
Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Q 16.
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?
Q 17.
Try to collect all the currently accepted meanings for the word ‘species’. Discuss with your teacher the meaning of species in case of higher plants and animals on one hand, and bacteria on the other hand.
Q 18.
Do you consider a person in coma-living or dead?
Q 19.
Some of the properties of tissues are not the constituents of its cells.
Give three examples to support the statement.
Q 20.
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.
Q 21.
Couplet in taxonomic key means .
Q 22.
What is a Monograph?
Q 23.
How is a key helpful in the identification and classification of an organism?
Q 24.
Linnaeus is considered as Father of Taxonomy. Name two other botanists known for their contribution to the field of plant taxonomy.
Q 25.
Can you identify the correct sequence of taxonomical categories?
(a) Species —> Order —> Phylum —> Kingdom
(b) Genus—) Species—> OrderKingdom
(c) Species —> Genus —>Order —> Phylum
Q 27.
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?
Q 28.
In a given habitat we have 20 plant species and 20 animal species. Should we call this as ‘diversity’ or ‘biodiversity’? Justify your answer.
Q 29.
The number and kinds of organism is not constant. How do you explain this statement?
Q 30.
What do we learn from identification of individuals and populations?
Q 31.
Properties of cell organelles are not always found in the molecular constituents of cell organelles. Justify.
Q 32.
What is meant by living? Give any four defining features of life forms.
Q 33.
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?
Q 34.
Why are living organisms classified?
Q 35.
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?
Q 36.
What different criteria would you choose to classify people that you meet often?
Q 37.
Illustrate the taxonomical hierarchy with suitable examples of a plant and an animal.
Q 38.
Define and understand the following terms:
(i) Phylum (ii) Class (iii) Family
(iv) Order (v) Genus
Q 39.
Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Q 40.
In a given habitat we have 20 plant species and 20 animal species. Should we call this as ‘diversity' or ‘biodiversity'? Justify your answer. –
Q 42.
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?
Q 43.
A scientist has come across a plant which he feels is a new species. How will he go about its identification, classification and nomenclature.
Q 44.
Brinjal and potato belong to the same genus Solarium, but to two different species. What defines them as separate species?
Q 45.
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.
Q 46.
Do you consider a person in coma-living or dead?
Q 47.
Define a taxon. Give some example of taxa at different hierarchical levels.
Q 48.
A plant species shows several morphological
variations in response to altitudinal gradient. Whengrownundersimilarconditionsofgrowth, the morphological variations disappear and all the variants have common morphology. What are these variants called?
Q 49.
What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?
Q 50.
The number and kinds of organism is not constant. How do you explain this statement?
