L22 : Questions - Cell Biology, Science, Class 8 Video Lecture

hello friends this video on sale part 22
is brought to you by exam for calm
normal appeal from exam so now this type
of questions let's look at some of the
questions and you can also get to know
that whether you got the lesson man or
not question number one
indicate whether the following
statements are true or false unicellular
organisms have one cent
what uni means one so eigen isms which
are made up of one cell so that's what
this statement says so yes this is true
muscle cells are branched so if you talk
about the different cells present inside
the human body you actually get a lot of
variety so when you talk about a nerve
cell or a muscle cell so yes they are
branched so it is also true the basic
living unit of an organism is an organ
absolutely not that is what we have been
learning in this lesson that the basic
you living unit of an organism is a cell
and group of cells they form tissues and
group of tissues will then form an organ
therefore the basic unit is said and
Reba has in regular shape is that's true
because this is our ally biostack and
that to its shape keep on changing so
when it wants to move from one place to
another or when it wants to take in food
so in such situations in its shape keeps
on changing as it so anyway is made up
of one cell and that step keeps on
changing its shape it doesn't have a
fixed shape question number two make a
sketch of the human nerve cell what
function do no cells perform so if you
look at a human nerve cell which is also
known as a neuron
what do they do they can impulse
from brain to different body parts or
from different water parts to the brain
so that's how brain coordinates with
different parts of our body for example
when you see something for example let
me take this example let's suppose you
touch a surface which is very hot or do
you immediately take your hand back
right because your brain tells you that
whatever you are holding right now is
very hot so just take your head back so
that instruction to move back take your
hand back comes from your brain
so all this transmission of impulses
takes place through the nerve cells so
these nerve cells how is their structure
they have got branched structure because
these kind of branch structure helps in
the process of transmission so if you
look at a nerve cell so this part it has
got three main parts so these branches
here they are called dendrites then you
have the cell body which is also on a
site incisal or cell body whatever you
call it and then this one dendrite which
is so very long this part is known as
the axon so these are the three
important parts of nerve cell now I am
NOT going to talk about each of the
parts right now because that will be
left for your higher classes so as you
put your higher classes you study the
same things but in little more detail
question number three write short notes
on the following cytoplasm and nucleus
cytoplasm is the fluid which is present
inside the cell enclosed by the plasma
membrane societal root cell class comes
from the plasma membrane so it is the
fluid enclosed by plasma membrane and it
is present inside
instead it has almost 80% water so it is
less viscous it is also quiet cytosol
all the organelles are embedded in the
cytoplasm so this fluid is cytoplasm so
you can see all the different organelles
will be embedded here
it also contains dissolved nutrients and
it can also dissolve the waste products
and send them out of the cell so it acts
as a medium basically for transfer of
materials
next is nucleus it is a specular open
structure present near the center of the
sense of this s nucleus it is present in
both plants and animal cells yes of
course it is the control center of the
cell because it controls many important
activities of the cells so one important
activity where it takes part is the same
division it plays a very important role
in cell division secondly it also helps
in the movement of substances across the
nucleus and the extra nuclear space so
the movement of substances across the
nuclear membrane so that also happens
that also is a function of the nucleus
it contained information for inheritance
now my kids look similar to their
parents because they can see some traits
from one generation to the next
and this information is the unit of
inheritance is contained in DNA and
where this DNA present DNA is present in
the chromosomes and where our proposals
present so chromosomes are present
inside the nucleus so that's how the
transmission of characters from one
generation to next happens and that is
why nucleus is so important so you can
see that if you look at a magnified
image of the nucleus so this is how it
will look like so here you have the
proband
which condense to form chromosome during
cell division so this is how chromosome
looks at on this chromosome you have
structures one genes and these genes
contain DNA and DNA is the genetic
material so this contain the information
are the genetic information question
number four which part of the cell
contains organelles now all the
organelles of components of the cell are
embedded in the cytoplasm so you see all
these are different cell organelles
these are various cell organelles so
when you see them they are all suspended
in the cytoplasm so we can say cytoplasm
contains the cell organelles question
number five
where are chromosomes found in the cell
state their function so chromosomes just
now we were talking about that so they
are found inside the nucleus of a cell
what do they do their main function is
during cell division because they
contain the information for inheritance
so if you see here these are the
chromatin trace so these trends they
contain DNA RNA and proteins and the
chromatic traits exist during the
resting phase of the sin that means when
the cell is not dividing but during the
dividing fields what happens is the same
these chromatic threads they contents
together to form these rod shaped
structures called chromosomes
and on these chromosomes annotated gene
which specifies our which determine a
particular trait of an animal of or of a
human being and these are these genes
are present DNA which is our genetic
material so that's how we can see that
chromosomes play a very important role
and for being carrier of inheritance it
plays an important role during cell
division because when cell divides the
part of the chromosome is who is being
passed on to the
new cells which are being produced and
that is how the information is actually
being carried forward from one
generation to another
so whatever chromosome is present in the
parent cell the part of it is passed on
to the next generation so that's our
some traits are some genes are being
passed on to the next generation so they
have some inner traits
now how this exact process takes place
that you will understand that we will
learn about cell division question of
the six cells are the basic structural
units of living organisms explain so why
do we say that
so when whenever it comes to structural
organization just think of this concept
that you have bricks which make up a
building so similarly you have cells
which make up an entire organism because
cells grouped together to form tissues
which in turn group together to form
organs organs grouped together before
organ systems and organ systems form the
entire organism so let us take this
example so you have many such cells
inside your body now some of them all
the cells do not perform the same
function so a group of cells decided to
perform a common function and those
group of cells together formed the lung
tissue these many such tissues joined
together to form his organs called hands
now many such organs know not only lungs
from the respiratory system but there
are other organs also for example you
have parents you have the windpipe you
have in fact you have the trachea you
have your nose you have the nasal cavity
you have lungs drawn Chiron curves all
these together one that is very three
system respiratory system alone cannot
form the organism there are many such
systems like circulatory system
digestive system excretory system so all
these systems together form the entire
organism so what is the basic level so
everything started from cell so
why we say that cells are the basic
structure and unit of living organisms
question number seven explain why
products are found only in plant cells
so chloroplasts contain chlorophyll
right and blow over their heads and
photos and pieces now do animals come on
photos and business know so plants come
on photosynthesis so they need
chlorophyll because without that they
cannot perform photosynthesis so that is
why chloroplasts are present only in
plant cells these flow paths also
imparts green color to the plants
because the probe will pigment is green
in color
question number eight so here we have a
crossword so here we have to complete
this crossword looking at the clues
which are given here
first let us fill the at cross ones so
it crosses those which are in this
direction so now the last here we have
number one this is necessity for
photosynthesis what do we mean for
photosynthesis only green plants do
photosynthesis and why are they green
due to a green pigment one chloro
businesses across that means in this
direction we have to fill it so thats
today so this is going to be close
roll film number trees maybe we have
number three is symmetry okay term for
component present in the cytoplasm so
what are the cell components which are
present in cytoplasm and organelles
writes it starts with O so we are
supposed to light here apart and ends so
these are ordinate number six let's go
to number six this is here the living
substance in the cell
so then time living substance inside the
cell is called what inside the cell we
have
fluid which is cytoplasm other than
cytoplasm or tens do we have the nucleus
and the nucleus and the cytoplasm are
together oil protoplasm so this is going
to be pro 2000 and finally number eight
this is number eight secure Mnet's of
inheritance present on the chromosomes
so which are the units of inheritance
what kinds of the traits from one
generation to another genes so now we
have completed that across once let's
look at town so this will go in this
direction number one here is a piranha
green plastic each plastics are green in
color
chloroplasts fact so this's clover roll
lasts next is number two this is number
two
for my collection of tissues now we saw
that cells want tissues tissues for
organs so this is going to be organ
number four waves alcohol this is it
it separates that weaken tens of the
cell from the surrounding medium so the
stain isn't the same and what separates
the stem from surrounding medium the
cell membrane right so it is going to be
membrane number five empty structure in
the cytoplasm
what is an empty structure it is nothing
but a vacuum or virtual and big spaces
inside is a lot of empty space but it
also contains a fluid so this kind of
structure is vacuum so that's why it
helps in storage number seven a group of
cells the cells form tissues so this is
going to leave issue so that's how we
have completed the crossword I hope this
would have been helpful to you so with
this we have reached towards the end of
this lesson cell and I hope that this
would have helped you there are quite a
couple of days
which I have just given an overview I
have not gone into the details because
the details have been discussed in
videos of higher classes like eleventh
and twelfth so in case you are really
interested you can read through those
videos of higher classes so I hope it
helps you so see you in the next lesson
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