Xylem elements proto, meta xylem Video Lecture - NEET

hello friends this video on anatomy of
flowering plants part seven is brought
to you by exam feel calm no more fear
from exam so to start with we will talk
about trap cheats so what are these
tracheids they are tabular structure
which is very very clear from this
diagram now a small tip which I would
like to give you as science and biology
you will we will talk about so many
different things when we talk about
allergy or when we talk about anatomy we
talk about so many different structures
so many new names so sometimes it
becomes very difficult to remember the
characteristics of each each part of a
plant right so it is always good to have
the picture in mind so if you have if
you recollect or if you try to
understand the characteristics of
tracheids looking at the picture and
then it becomes easy to remember it you
don't get confused with what is the
tracker and what is a lesson alright and
that is why we show you so many pictures
ok the track incentive Euler structure
the structure is almost like a tube
conduct water and minerals vertically
now I think when we talk about xylem the
conduction is mostly vertical because
the roots are at the below and all other
parts of the plant is above so the
conduction of water and minerals has to
happen upward so that has to be in the
vertical direction so this tibula
structures or track aids actually
conduct water and minerals vertically
these are dead cells without protoplasm
so what is protoplasm it is nothing but
the living matter or the fluid present
inside the cell the cytoplasm basically
so there is no cytoplasm now once the
cell is dead there are no cellular
processes happening inside the cell
correct there is no respiration
happening there is no need of any of the
cell organelles
there is no protoplasm the next one that
is vessel what does it do
they are also tubular cells with little
tapering ends okay so the ends it goes a
little like this I mean they they are
not exactly the entire thing is of the
same thickness but towards the end it
becomes little tapering now each vessel
is made up of many cells and each cell
is known as a vessel member so many
vessel members together form a vessel
these are lignified cell walls without
protoplasm again great also do not have
protoplasm so they are also dead cells
and the walls are dignified that means
lignin is present on the wall whenever
lignin lignin is something which
actually makes the wall very strong it
increases the strength so these vessels
also have got strong cell walls however
perforations are present what are
perforations perforations are small pore
like structures or small holes which are
present on the walls of the vessels now
as I said the walls are lignified so the
walls are made up of lignin very strong
words but they do have some holes what
is the purpose of the holes through
these holes the vessel members are
interconnected as I said one vessel is
made up of many vessel members so when I
say a vessel so here in this picture you
actually see a vessel now this vessel is
not one single vessel this vessel is
made up of many vessel members so many
vessel members is constitute one vessel
now these many vessel members so
basically here you might wonder that
there is no tapering end which I can see
because this itself is made up of many
tube-like structures which are having
tapering ends so these perforations
which you
see these perforations actually help the
vessel members to interact with one
another right so that is the purpose of
these perforations the third one is
xylem parenchyma so what does it do
these are thin want living cells so now
again these are parenchyma cells so they
are living cells
so now introduce you monthly water
spiral Cairo parenchyma is nothing but a
simple pattern in tissue so here inside
him one of the components is a
parenchyma
so parenchyma cells are also one type of
cell which is present inside desire so
they are living cells as we discussed
before also and they are generally thin
white the walls are not that thick so
here the cell walls the thin cell wall
is made up of cellulose so it is like
the moderately rigid the help in food
storage parenchyma the basic packing
tissue we talked about it before food
storage is one of the important function
of parenchyma they conduct water
sideways now just now some time back I
told you that when I talk about xylem
the conduction should be primarily
vertically but not all will be is
vertically because there might be some
plants where where the plant is moved at
all and low right there are some plants
which grow horizontally we have a large
alert we have left a lesson on diversity
in living organisms right where we
talked about the plant kingdom and we
saw we learnt about a variety of plants
we talked about so many plants like
stones and suckers runners so we saw
those nuns they do not grow vertically
upwards they grow horizontally so when
something is growing horizontally view
if we say that the xylem is going to
conduct only vertically so what happens
you twos and floods which grow
horizontally so they are gone they are
dead so there has to be some
which will conduct the water and
minerals even sideways so that is done
by xylem parenchyma not really talking
about those plants even you consider a
normal plant we say then water and
minerals will be conducted only
vertically that is what will happen it
will go up from roots to the step now
there are so many natural branches here
and there so what happens to lose that
lateral branches for that you need to
conduct water sideways as well for
example this is a plant okay these are
the roots so now water is getting
conducted vertically now this time we'll
also have branches now this branches
might also have sub branches right so
now if you say that the water will only
be conducted vertically then what
how will the water get conducted
sideways because even daily need water
and minerals right so both vertical
conduction and sideways conduction are
needed so for the sideways conduction is
xylem parenchyma and for the vertical
conduction is now trackage the fourth
component is xylem fibers these are
nothing but they are generally used for
support just to support right so now we
spoke about all the four elements we saw
that they all perform some specific
function now how do they all synchronize
their function now as our goal in size M
so that what is the function of xylem as
I mentioned before the function of xylem
is to conduct water and minerals from
roots to all other parts of the plant
now in order to do that it needs to
conduct water vertically from roots to
upward for that we have tractors it also
needs to conduct water sideways so that
all the lateral branches can get it so
for that we have
parenchyma now you also need to support
the plant a basic support to the plant
is always needed because as the plant
grows the need for support keeps on
increasing okay so for that we have
xylem fibers so each of these elements
performing a particular function but all
together they are performing the entire
function of them xylem right so that is
house animals a complex tissue okay so
with this I think the structure and
function of xylem is quite clear another
important point to note there else
gymnosperms
lack vessels in their silent so there
are no vessels in sim noscopes because
drink nozzles do not have valves they do
not have flowers right gymnosperms are
like buying day older they are all
gymnosperms where we do not have flowers
so such plants do not have vessel that
is one important point to be noted here
we have talked about produce I demand
data as I am so this is another concept
which comes into picture because there
is one xylem which is formed before and
it is another xylem which is formed in
the later stages of plant life cycle so
that is why we have two different terms
proto xylem and betas iron so let us see
what are they
proto Salem is the first formed primary
xylem so the first form designer messed
up proto xylem it has a smaller lumen so
when I say smaller lumen what is lumen
lumen is basically the inside cavity of
a tube like structure for example this
is a tube this is another tube so both
are tube right but here the lumen is
small so this space which you have
inside the tube that is referred to as a
lumen here here this is the
human so this is a narrower looming
whereas this is a wider human now when I
talk about proto Zion they have narrow
lumen smaller humans so proto's Alam can
be represented something like this
the next one is bet asylum that is the
later formed primary xylem so both are
primary xylem now you might again have a
question in your mind what does this
primary xylem and secondary xylem know
so that will become clear after some
time so for now you just know that okay
primary xylem is the only thing that
exists what is that it resides that we
will discuss later
so in primary xylem itself there are two
stages one is earlier form which is
proto Salem domain which is formed later
is the mega salad and this matters I am
has a larger lumen so it is somewhat
like this a wider lumen so it will look
somewhat like this bigger lumen correct
okay now again there can be different
types of arrangements of proto xylem and
mater's atoms now when we talk about the
internal structure of different plant
parts like the internal structure of the
root or the stem we see that the produce
eylem at the meta xylem are arranged in
some specific fashion so basically there
are two possible arrangements of proto
xylem and made has iron
the first one is end arch and the second
one is exact so these are the two
possible arrangements of proto xylem and
mecca's iron now what happens in end
arches the proto xylem lies inside the
met Asylum what does that mean that
means the proto xylem is towards the
center and the meta xylem is towards the
periphery so that is when it is possible
that the protoss island lies inside the
mental asylum and so in this case it
would be something like this let us
suppose these are the proto's eylem and
outside the proto xylem would be the
metas iron
so here basically the meta xylem is
towards the periphery or towards the
boundary and the proto xylem is towards
the center right so this arrangement is
known as end arch now when I talk about
exert it is chose to the opposite so
exact X means outside
so here the proto xylem lies outside
metas item so that means the smaller
ones will be outside and the bigger ones
will be inside so the metas Island would
be towards the center and the proto
xylem would be towards the benefit an
arrangement like this now you might ask
where is its application I mean where do
you actually see such arrangements like
that it is arranged in this way or that
way so where do you actually see them so
now the answer to that is when we will
talk about the internal structure of a
root or the internal structure of a stem
this is the arrangement that is exact
this is the arrangement which you will
see in group whereas this is the
arrangement that is n Dodge which you
will see in stem so when we will talk
about the just remember this in your
mind then we will talk about the
internal structure of stem you will
actually see that the meta xylem is
outside the protoss item and when we
talk about the root we will see that the
proto's item is outside the metas item
so these are the two different types of
arrangements of proto xylem and metas
iron oh thank you please visit
www.payoor.com to watch more videos
attempt free online test
get free study material find tutors and
mentors thank you once again