Reproduction in Plants (Part - 5) - Science, Class 9 Video Lecture

other students that is retinol from the
part from where we left during the last
lecture that is reproduction alarms the
topic will take today is fertilization
in a flowering plant it's a very
interesting topic which deals that how
the fertilization takes place among
plants and how the c is for and the come
see it give rise to the complete new
sapling by definition fertilization is
nothing but a process of fusion of male
and female give it if we see the process
it is different in different plants but
the basic phenomena is the fusion of me
as well as female gametes what happens
that suppose this is the structure of
the female reproductive part of the pan
this here that pollen grains are being
booted and this is the female
reproductive part now the next step will
be the transfer of the gamey from here
to here it's a process which involves
formation of the pollen pollen tube it
grows to the length of this type which
is strife and ultimately reaches to the
oven where the female gamete is present
the pollen tube contains to welcome each
suppose this is the tube which is formed
in different plants this formation is
the process different but the contents
are two main
memes from pollen grain which are
released into embryo sac see the help of
this beautiful diagram we can understand
the phenomena of formation of pollen
tube see this is the pollen grain this
is pollen grain and this is pollen tube
this is the germinated nucleus and this
is the cumulus when this pollen is
present at the top of the stigma this is
how it travels down along the entire
length of the piston and ultimately
reaches to the odium to transfer the two
sperm cells which have just discussed
the poor from where the pollen tube
enters into the female reproductive part
is called micro file where the oval is
present and this entire structure is
called as overly when we see the
detailed structure of opening from
inside this is how it looks you can see
this is a pollen tube carrying two sperm
nucleus or two sperm cells and at the
side where it enters it is known as
microbial this is micro file now what
will happen that these two sperm cell
will be transferred inside the hope
you'll and the next step will be
followed the internal structure is like
this the binuclear itself two haploid
nuclei these are the two haploid nuclei
and these are the that white a nucleus
present now the next
diagram which shows the further changes
taking place during the process of
fertilization that is this is the
haploid nucleus and this dark one is
known as applied the sperm nucleus this
is wrong female and this is from May
what will happen that this pollen tube
it sometimes it be generated sometimes
it remains in the regenerative forum but
after releasing the male gamete the
haploid egg nucleus and applied sperm
nucleus they comes together and choose
in forming diploid zygote you can see
this yellow colored part it is a half
wide nvs and this dark color part which
is f widest pump when both of the
emphasis waveforms that deploy o jogo
but this process is still not
complicated what happens that the
remaining one nucleus which is
transported along this sperm cell it
fuses with the endosperm cell and
forming triploid and dysfunction so the
process of fusion of game it is known as
double fertilization when we will say
here one as we have seen that one male
gamete when it fuses with a to form
diploid zygote and another male give
meat fuses with polar nuclei these two
structures egg and polar nuclei they are
part of view when if you
is then it results in the formation of
cheap wine ups which will develop into
endosperm in future the process of a
fusion of one of the male gamete with a
and other male guinea with polar nuclei
is called as double fertilization means
the process if called together then it
is known as double fertilization whereas
the fusion of one male give meet with
two polar nuclei to form the diploid
endosperm is godness chip confusion so
we should be very clear about these two
terms that is double fertilization and
triple fusion I am repeating one male
gimmick chooses with a forming he
provides I go this is known as
fertilization and the second main
gimmick when fuses polar look like
forming chip right nucleus both the
process our God has double fertilization
whereas formation of one male he meet
with deployed polar nuclei these are the
diploid cells forming this is our gain
deployed and forming of n plus 2 and
resulting in 3m is called as chief
infusion after fertilization sepals and
petals having no rule they are being
shredded and the next the part of the
development of seal starts the function
of address form here is very important
it provides nourishment to the
developing
and Embry fertilization is a very
important project process in which many
changes occurs Oh fuel which we have
just seen in a flower it changes into
scene and ovary changes into fruit wall
as far as the difference between
pollination is concerned let us end this
topic at this level let us discuss the
pollination if we compare between self
and Rose pollination then what are the
differences see that limit is it the
same but in case of self-pollination the
pollen grains are transferred from
flowers of the same plan or from same
flower itself but increase of
cross-pollination the process involves
transfer pollen grains from another
planet or other tree if it can occur it
can occur even without flour even when
flower sorry even when the flower is
closed it cannot eliminate uses or
harmful character swear by
cross-pollination useless or harmful
characters can be eliminated
self-pollination is method which is
highly useful to preserve the race then
between self-pollination and cross
pollination are many let us consider
that the self-pollinated flower will
never help in production of new
varieties or species because here what
will happen the characters are conserved
they are not changed where as in cross
pollination the chances are there that
the characters may be transmitted from
one plant to them another plan so there
are always chances of variation so this
is an important phenomena associated
with cross-pollination because you know
species has to change itself according
to the changing environment and
cross-pollination helps in changing or
modifying means it introduces variations
in offsprings so this is how cellphone
ination differs from cross-pollination