Classification System : Artificial & Natural Video Lecture - NEET

hello friends this video um kingdom
plantae part 2 is brought to you by exam
feel calm no move your exam as I said
before we go ahead with the different
sub classification or sub categories of
plant kingdom let us understand the
different classification systems so we
should actually know that how the
classification is done so if we will see
that how different classification
systems evolved in its time and how
better classification systems came up
with the passage of channel so here we
will discuss about the three
classification systems that is
artificial system natural system and
phylogenetic system so we will talk
about each of these systems one by one
and we will see that each of these
systems has different basis for
classification I mean we all know right
what is the basis of what do we mean by
basis of classification that means what
are the characteristics or what are the
features based on which organisms are
classified
so that basis of classification is
different for each of them and let us
try to understand each in little more
detail so let us start with the
artificial classification systems the
word artificial what does it mean
artificial means something which is not
natural something which is man-made
so this artificial system is the most
ancient system of classification so in
the earlier days when did this concept
of classification came up so the type of
classification which was honored that
time was the artificial ossification
system so what was the basis of this
classification systems it was based on
the external morphological characters
external morphological characters what
do we mean by that the characters which
are visible externally morphology is
something related to the external
structure of an organism so for example
the color color is something which is
external
visible to everybody for example some
some animals have a lack in color some
animals are red in color some trees are
green in color some trees are something
different in color so color is an
external morphological character again
if you take other examples
it is like the number of leaves in a
plant the shape of the leaves in a plant
so these are some of the characters
which are externally usable so based on
those externally visible characters
there are organisms where classified so
even plants they're also classified into
different types based on such features
like number of leaves in that plant the
shape of the leaves shape of the plant
as such height of the plant color of the
plant so based on such characters now
let us look at the advantages of
artificial system now it is very obvious
that closely related species could be
classified because based on these
external features also you can at least
make a difference between two different
organisms because their external
appearance are quite different so if we
take example of plants for example if
you take and see there are a small a
lotus plant and if you consider a cactus
now in the external appearance itself
they differ in many things so such
species could be classified so closely
related species could be classified
right okay so closely related species
were together again closely related
species we're together so some sort of
classification was possible so at least
something was better than nothing so we
were doing some classification and that
was good enough now looking at its
limitations equal weight age to
vegetative and sexual characteristics
okay
so here I think we have something to
understand first what do I mean by
vegetative and sexual characteristic and
what do I mean by equal weight age to
these characteristics so fattest first
blood
try to understand water vegetative
characteristics and what are sexual
characteristics when I talk about
vegetative characteristics they are the
somatic characteristics or the somatic
structures of plants that means the
structures of a plant body so they are
vegetative characters examples of
vegetative characters would be the root
system of the plant the shoot system
that is the stem the leaves of the plant
so they are all vegetative characters
now when I talk about sexual characters
I am talking about the reproductive
structures so we can note it down here
so when I talk about vegetative
characters I am talking about the
somatic structures that is the
structures of the plant body when I talk
about the sexual characteristics we are
talking about the reproductive
structures so now these reproductive
structures are again different in
different types of plants for example if
we take the flowering plants so they're
the reproductive structure is the flower
so the flower and fruits they form they
play a very important role in
reproduction but if we consider the non
flowering plants for example the pine
trees which you see each other in the
hilly areas they do not have flowers
they neither have fruits so in their
case they are reproductive structure is
something else their reproductive
structures are cones so we will talk
about all these things in detail in the
later half of the lesson but what I am
trying to see is this reproductive
structures in different plants are
different now maybe you have two types
of plants where the you have to blanch
the whose vegetative characteristics are
the same by their reproductive
structures are very much different so
that is also possible now in this system
of classification equal weight H was
given to both these structures that
means if two and the amount of
importance you give to the external or
this bodily structures
the plan same amount of significance was
given to them reproductive structures
but the fact was that when you consider
the vegetative characteristics they can
change with time because the like the
stem of the plants can change with time
the leaves can change their color with
time the number of leaves can also
change with different seasons
so the vegetative characteristics they
are not constant with time they keep
changing with time due to many
environmental conditions so they should
not be considered as much as the sexual
characteristics for classification
because sexual characteristic is
something which is permanent it is not
going to change with time it is not
going to get affected by the weather
conditions it will still remain the same
for example in a flowering plant or
where you have fruits so their their
reproductive structures will remain the
same doesn't matter even if they lose
their leaves or the color of the leaves
changes so the sexual characteristics
are not variable with time but the
vegetative characteristics will change
with time so it is really unfair to give
both of them equal weight age to
classify different types of plants
sexual characteristics should get more
importance than the vegetative
characteristics so this was one
important limitation and because of this
limitation it was seen that many species
which differ in their reproductive
structures even they were another same
group just because they are somatic
structures were similar so just because
they looked similar from outside they
were put into the same group even though
their internal structures or their
reproductive structures their
reproductive process was completely
different from the other type of plants
so this was a very important limitation
of this artificial classification system
so here you can see in this picture one
is a plant which bear fruit the other is
a plant which is a pine tree which
doesn't be a fruit so both of them even
though if you look at
of outside world will have the roots
both will have stem both will have
leaves but that doesn't mean that they
should fall under the same category so
more importance has to be given given to
the sexual characteristics so this
artificial classification system was not
a great success by then since it was the
ancient one the first one which came up
so at least it showed us the way of
classification so thereafter which time
came up the natural classification
system so let us see what is this
natural classification system do so in
the artificial system everything was
defending the basis of classification
were the external structures so in this
case external as well as internal
structure the characters were considered
for classification so that means it was
something better than the artificial
system because not only the external
potential structures were also
considered so now in it when I say
internal characters so what kind of
characters am I talking about
so internal characters would mean for
example if we are classifying plants so
not only the leaves stem and root of the
plants will be considered but also the
reproductive structure of the plants the
plant embryo all these things we're also
being needs to be considered the
chemicals which are present inside the
plant so all these kind of things when
taken into consideration so this was
anyway a better mode of classification
than artificial systems so advantages
overshadows limitations of artificial
system because as I say artificial
system was very much superficial so it
could definitely overshadow the these
advantages of artificial system
establishes relationship between
organisms now how could the system of
classification establish relationship
between different organisms that's
because when they actually start
classifying organisms so what do we do
we actually try to study the
similarities and dissimilarities between
different organisms so the organisms
sharing a lot of similarities with each
other we see that they are related to
each other in the way that maybe they
share a common land system so that is
how we can establish a relationship
between different organisms let us take
an example if you consider a tiger and a
lion and a cat you see that there are a
lot of similarity between these
organisms even though a tiger and a cat
they are not the same organism right
they are two different organisms but
still they share a lot of similarity so
looking at those similarity and that
similarity is not only in its appearance
it is both external characters as well
as internal characters so we see that a
tiger and a cat are more closely related
than a tiger and a dog because the
similarities between a tiger and the cat
is much more than that of a tiger and a
dog so looking at the similarities and
dissimilarities definitely helps us to
classify organisms and it also helps us
to establish relationship between
organisms but again even this system had
certain limitations so there are some
disadvantages associated with this
system as well closely related organisms
can also differ in important properties
now even though two organisms have a lot
of similar external characters a lot of
similar internal actors but even then it
was seen that they differ from each
other in some very very important
properties so one of the one of the best
examples would be the pathogenic
bacteria and the known pathogenic
bacteria so see both are bacteria so as
such their structure remains the same
even though it doesn't structure their
behavior their habitat and their role of
nutrition all these things
mean the same for both these kind of
bacteria but if you look at the
pathogenic bacteria they are pathogens
that means they can cause disease they
can cause harm to their hosts but you
look at if you look at the
non-pathogenic bacteria they do not so
behavior-wise
they both are completely different from
each other so with this classification
system so because two bacteria before
another same class so they're Windows
further classification of bacteria into
pathogenic and known pathogenic right so
that was one important limitation of the
natural system of classification so
talking about this we can take the
example of pathogenic and lorn
pathogenic bacteria so what did we see
how did we improve with the natural
system of classification the natural now
the natural fit system of
classifications basis do not change with
time so now here more importance is not
given to the vegetative characters both
vegetative and sexual characters are
considered and more importance is given
to the sexual radicals that is the
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