Class
IX Science
NCERT
Solution for Diversity in Living Organisms
Q1. Why do we classify
organisms?
Ans. For easier and
convenient study we classify organisms.
Q2. Give three examples of the
range of variations that you see in life forms around you.
Ans. (a)
Small cat and big cow
(b)
Grass and banyan tree
Q1. Which do you
think is a more basic characteristic for classifying organisms?
(a)
the place where they live.
(b)
the kind of cells they are made of Why?
Ans. Classification based on
living place is more basic as there can be wide variations in organisms
living in a given place.
Q2. What is the
primary characteristic on which the first division of organisms is made?
Ans. Nature of cell is
the primary characteristics on which the first division of organisms is
decided. Based on this critefion life forms can be classified into prokaryotes
or eukaryotes.
Q3. On what bases are
plants and animals put into different categories?
Ans. Mode of nutrition
and presence or absence of cell walls.
Q1. Which organisms
are called primitive and how are they different from the so-called advanced
organisms?
Ans. Organisms with
simple cellular stracture and no division of labour are called primitive.
Advanced organisms, like mammals have millions of cells and there are system
for different biological functions.
Q2. Will advanced organisms
be the same as complex organisms? Why?
Ans. Yes, advanced organisms
means greater degree of evolution which leads to more complexity.
Q1. What is the criterion for
classification of organisms as belonging to kingdom Monera or Protista?
Ans. It is the presence
or absence of a well defined nucleus. Monera has no nuclear membrane, while
Protista shows well defined nucleus.
Q2. In which kingdom will
you place an organism which is single-celled, e,ckaryotic and photosynthetic?
Ans. Protista.
Q3. In the hierarchy of
classification, which grouping will have the smallest number of organisms with
a maximum of characteristics in common and which will have the largest number
of organisms?
Ans. Organisms belonging to
Kingdom Monera will have the small number of organisms with a maximum of
characteristics in common. And kingdom Animalia will have the largest number of
organisms.
Q1. Which division
among plants has the simplest organisms?
Ans. Thallophyta or algae.
Q2. How are pteridophytes
different from the phanerogams?
Ans. Pteridophytes have naked
embryo and inconspicuous reproductive organ whereas phanerogams have
well-differentiated reproductive organs and covered embryo.
Q3. How do gymnosperms and
angiosperms differ from each other?
Ans. Seeds are naked in
Gymnosperms and are covered in angiosperms.
Q1. How do poriferan
animals differ from coelenterate animals?
Ans. Animals from
Porifera show cellular level of organisation, while those from Coelenterata
show tissue level of organisation.
In Porifera there is no
division of labour, while in Coelenterata some division of labour is seen.
Porifera do not have
coelom, while coelenterata have coelom.
Q2. How do annelid animals differ
from arthropods?
Ans..
Q3. What is the
differences between amphibians and reptiles?
Ans.
Q4. What are the differences
between animals belonging to the Aces group and those in the tnarnmaliu group?
Ans.
Q1. What are the advantages
of classifying organisms?
Ans. Advantages of
classiticattion:
Better categorization of living beings based on common characters.
Easier study for scientific research.
Better understanding of human’s relation and dependency on other
organisms.
Helps in cross breeding and genetic engineering for commercial purposes.
Q2. How would you choose between
two characteristics to be used for developing a hierarchy in classification?
Ans. Gross character
will form the basis of start of the hierarchy and fine character will form the
basis of further steps of single the hierarchy.
Example:
Presence of vertebral column in human beings can be taken under
vertebrat.
Presence of four limbs makes them members of Tetrapoda.
Presence of mammary glands keeps them under mammalia.
Q3. Explain the basis for
grouping organisms into flue kingdoms.
Ans. Basis of Classification:
(a)
Number of cells
(b)
Layer of cells
(c)
Presence or absence of cell wall
(d)
Mode of nutrition
(e)
Level of organization
Q4. What are the major divisions
in the PIantae? What is the basis for these divisions?
Ans. Major Divisions of
Kingdom Plantae:
Q5. How are the criteria
for deciding divisions in plants different from the criteria for deciding the subgroups
among animals?
Ans. In plants body basic
structure is a major criteria based on which Thallophytes are different from
Bryophytes. Apart from this absence or presence of seeds is another important
criteria. Gymnosperms and angiosperms are further segregated based on if seeds
are covered or not. It is clear that it is the morphological character which
makes the basis for classification of plants. In animals classification is
based on more minute stnictural variations. So in place of morphology, cytology
forms the basis. Animals are classified based on layers of cells, presence or
absence of coelom. Further higher the hierarchy animals are classified based on
presence or absence of smaller features, like presence or absence of four legs.
Q6. Explain how animals in
Vertebrata are classified into further subgroups.
Ans. Vertebrata is
divided into two superclasses, viz. Pisces and Tetrapoda. Animals of Pisces
have streamlined body with fins and tails to assist in swimming.
Animals
of Tetrapoda have four limbs for locomotion.
Tetrapoda
is further classified into following classes:
(a)
Arnphibia: Are adapted to live in water and on land. Can breathe oxygen through
skin when under water.
(b)
Reptilia: These are crawling animals. Skin is hard to withstand extreme
temperatures.
(c)
Aves: Forelimbs are modified into wings to assist in flying. Beaks are present.
Body
is covered with feathers.
(d)
Mammalia: Mammary glands present to nurture young ones. Skin is covered with
hair. Most of the animals are viviparous.
)%20(4).png)
0 Comments
Comment Related Post
Emoji