Liverworts, Structure, life cycle - Plant Kingdom, Biology, Class 11 Video Lecture

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Plantae part 12 has got to you by
example rock on no more your exam but
I'll whites also sub-classification was
needed because the bryophytes also it
was seeing that there were two
categories into which they can be
classified because those two faculties
differ from each other in many important
characteristics so what about those two
categories
liverworts and mosses so these were the
two sub classification of bryophytes let
us study the characteristics of
liverworts now when I talk about liver
words almost around 9,000 species of
liver wats exist on this earth so can
you imagine how you which that number is
now when you talk about their appearance
some of them exist as leafless talents
that means without leaves whereas most
of them exists as leafy palace so they
have leaves talking about their habitat
they prefer moist and shady habitats
they not want too much of light plant
body is collide there is not too much of
distinction between the different parts
however they have a stem like structure
and they also have tiny leaf like
structures so the body differentiation
is obviously far better than the
caliphates but still it is not too much
distinct as well there are two types of
liver Watts depending upon whether they
have leaves or they do not have leaves -
hallows reaper watts and otherwise this
leafy liver watts
so the Thanos River watts are those
which do not have the leaf like
structures so here you can see a picture
which display the tallow sliver watts so
the example of italo svevo most is
luenell area cruciate so held in that
picture in the picture you can see that
little area so here you see these
structures which are displayed they are
not they do not carry anything like leaf
so they do not have that kind of
structure it is just the talus which is
the display that is why they are got
fellows liverworts
the other one is leafy liver watch here
you can see
can actually see a stem like structure
like this and on this you see small leaf
like structures lengths so these are
known as leafy leaver watch so example
of a leafy liverwort would be skip
annular species now these leafy
liverworts look quite similar to mosses
we spoke about verses right so these
labor watts look quite similar to mosses
however there are differences between
mosses and these leafy leaver watts so
when I say Palace you understand what it
is it is the plant body it is generally
flattened and sometimes it is ribbon
like with a branching structure so this
is about the basics of liverworts now
considering examples of labour watts
much fancier is a very popular example
of liverwort this is how they look like
so here you can see in the picture they
have got this umbrella kind of a
structure so my can Tia Lucia this is
how it looks like Borella so here you
see you do not they do not exactly look
like a plant with a distinct stamp and
stinky leaves but they at least have
some basic structure of leaves and steps
so these are some of the examples of
liverworts now let us talk about
reproduction in liverworts first we
talked about asexual reproduction what
are the different ways by which they
reproduce asexually
so first is fragmentation of thelight
tala is nothing but the plural of talus
so fragmentation again the same thing
here what happens is the talents of the
plant so any part of the plant may be
older plant parts will die off so that
new and branches become separated by
specialized web-like structures or by
leaves that drop off the plant for
example palaces this plant body so you
can eat part of that plant body get
separated from the plant and if it
reaches somewhere else
give rise to a new colors all together
so that is known as fragmentation is a
scene in plants like tritium so small
part of the palace will separate once it
reaches the soil now how will it reach
the soil it might reach the soil by wind
air or rain so then they can develop
into a complete new river world the next
mode of asexual reproduction is gamma
formation so what are these gamma gamma
are the propagating structures in talos
liverworts this is a very important term
Gavin what a Grammy you have here in
this picture you can see some cup shaped
structures right so these cup shaped
structures are known as gamma cups and
inside these cups
you have the gamma so gamma are nothing
but spores and not exactly spores but if
these are also similar to sports so each
Cup will have numerous gamming now these
gammas will be released from the cups
when water droplets splash into the cups
but exactly these are like cups
containing lot of gamma
now when water falls on air these these
gamma might come out and when they come
out they get transported to some other
sites where they grow into new plants on
you individuals so that is how a sexual
reproduction happens by with the help of
gamma so what a gamete are these are
propagated structures in fallows leaper
watts so these are mainly the two ways
by which liberal watts reproduce
asexually now let us talk about the
sexual reproduction in liver watts so
sexual reproduction definitely involves
damage so here we need to gametes for
fusion
so here male and female organs can be on
the same Ally or on different areas so
it is not important that in one
if you should have the male organ as
well as the female organs they can be on
the same plant or they can be on
different plants for example so let us
now discuss the sexual reproduction in
liver watts so for sexual reproduction
as we know we need two Granite's for
fusion
so fusion of gametes will give rise to
the new organism so here we need a main
or them and a female organ so that the
male organ will produce the male gamete
female organ will produce the female
gamete now it is not necessary that the
male and the female organs are on the
same color they can be on the same
palace they can be on different Ally as
well now mostly what happens is that in
case of leafy libre water so if you
consider the leafy liver what it is seen
that the main and female structures are
on different plants or are on different
Kalai but if you consider the thatthose
liver wats it is seen that the male and
female structures are produced on bodies
which are umbrella-like structures or on
leaves so they are produced on
umbrella-like structures in case of
caddos liver ones so here we will see
how does the process of sexual
reproduction take place so let us have a
look at that so in this case what will
happen so there will be a gametophyte
again gametophyte is that part of the
plant which produces gametes so the
gametophyte will produce the gametes and
then these gametes will undergo fusion
so when they undergo fusion what will
happen is I got will be formed now these
zygote will grow to form the sporophyte
and then this sporophyte
we'll produce the spores and then these
spores will again germinate to form the
gametophyte so this is basically the
cycle here also now these garments which
we are talking about are the haploid
gametes
but the zygote which is formed here is a
diploid zygote again the sporophyte
which is formed by the growth of the
zygote is again a diploid phase now how
do these sporophyte survives now this
4:05 remains attached to the gametophyte
because everything is happening on the
gametophyte because there is a male
gametophyte there is a female
gametophyte as I told you before also
that the male gametes from the male
gametophyte is carried to the female
gametophyte so the pair is the fusion
taking place the fusion is taking place
in the female gametophyte so the zygote
is formed in the female gametophyte now
the zygote grows to form a sporophyte so
where is the sporophyte formed it is
formed on the female gametophyte so it
remains attached to the female
gametophyte so the sporophyte will
receive all its nutrition from the
female gametophyte and then it will
produce the spores these spores will
germinate to form the gametophyte again
so this gamma 2 fight is a haploid state
so in this case which phase do you think
is the dominant phase of the life cycle
is it the gametophyte or the sporophyte
so your gametophyte is the dominant
phase because it is long-lived
it is the one gametophyte is the plant
which we see like the plant which we see
as leaf or what theta is nothing but
gametophyte because they are capable of
producing the gametes but sporophyte is
an intermediate stage in life cycle
which doesn't last for a longer time it
just lasts for some time and then it
produces spores so the sporophyte phase
is gone so we can say that haploid
gametophyte is the dominant phase of
life cycle in this case so this is a
very important thing to remember so you
should know the life cycle of each
of plan and should also know which is
the dominant phase of the lifecycle so
this is the basic lifecycle now here
also there are a couple of things that
we should really need to know so why did
we study here about the sporophyte the
sporophyte remains attached to
gametophyte so that is one thing to be
noted here now when we look at the
structure of the sporophyte so let us
suppose now let us suppose if this is a
sporophyte so when we look at the
structure of a sporophyte it is divided
into three parts one is capture the next
is Sita and the bottom portion is food
so these are the three parts of a
sporophyte sporophyte is nothing but it
is like a small employer kind of thing
the zygote grows to form the sporophyte
the bottom part is for food the topmost
part is called caption and the middle
part or the body is known as Sita so
from where are these spores produced the
spores are produced in the capsu spores
are present in the capsule part of the
sporophyte right so I think the sexual
reproduction cycle of liverworts is also
clear okay so this is how it looks like
this is the IQ archieve on you for our Q
value for is the female part so this is
the female gametophyte and it will
produce the female gamete that is the
egg this is the male gametophyte so it
will produce the male gametes and the
bail damage will be carried from the
male gametophyte to the female
gametophyte with the help of what so let
us now talk about the sporophyte and the
gametophyte in little more detail so
here this picture in illustrate
sporophyte and gametophyte in a nice way
so sporophyte is the diploid stage as I
told just now it develops from the
zygote so here in this picture you can
see this portion is the gametophyte that
is the regional plant so it produced
gametes the gametes fuse they form a
zygote
I got grow to form a sporophyte so
sporophyte is still attached to the
gavotte effect so it begins to grow out
on top of the archegonium on the female
gametophyte plant as I said it will grow
on top of the female gametophyte plant
now considering its structure as I said
it has three parts food Sita and cap
shoots so food is the bottom most part
of the sporophyte citta is the body of
the spawn 5at capsule as the head of
them spawn right so this is capsule this
is Sita and this is food so food anchors
to gametophyte so food actually helps to
keep it attached to the gametophyte Sita
is the long erect stalk it transfers
water and nutrients from gametophyte as
I said the sporophyte will receive all
its nutrition from the gametophyte so
the stock or the tube-like structure
will help the nutrients to move up the
capsule is the head portion of the
sporophyte where spores are produced so
this is a structure of a sporophyte so
here in this picture you can actually
see the sporophyte that is a real
picture of levo wall scanning the
sporophyte you see these brown colored
spores so this is how they look like in
real life so they remain attached to the
gametophyte so here you can see this is
the gametophyte green colored structures
on that you have the stock or the Sita
and this is a spoon thank you please
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