Sister Chromatids vs Homologous Chromosomes Video Lecture - NEET

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what is this let us quickly distinguish
between the sister chromatids and the
whole yoga school zones because they
many of people get confused with these
students may love them think that both
are the same thing but actually they are
not so they have two different things
and you actually should move the exact
difference between the two so when we
talk about over Lois chromosomes what do
we say what are they as as I mentioned
before also about Volos chromosomes they
add a set of one maternal and one
eternal phone so when we talk about
homologous chromosomes we are actually
talking about for every trait one copy
is contributed by the father and one
copy is contributed by the mother right
so a second for one of those roles all
would look somewhat like this let me
suppose this is one chromosome this is
another Pro so now both of these can be
homologous chromosome maybe this one is
the pattern of chromosome that if it is
contributed it has come from the father
and this is the maternal promotion
because it has come from her mother so
here if you see these chromosomes are
still not duplicated this is like a
single chromosome brain so they are
unduplicated over locus chromosomes and
these two are over locus for so now when
we say over over only thing so these two
chromosomes will have same shape same
size and they will also have the same
type of key at the same location so if
this problem have a gene here which
corresponds to handle it so this
chromosome will also have a gene here
which will correspond to Heather if this
chromosome has a gene here which
corresponds to I cut it this program
will also have a gene here which will
correspond to - but the values
their forms might be little different
maybe this this gene for here for then
here say it's black and this gene for
hair fallacy is brown so that is
possible but it has to carry the same
type of gene at the same location on the
clothes so these are all roll overs
chromosomes so they carry the same
sequence of gene as I said so whichever
type of gene is present at whatever
location of mine chromosome the same
sequence has to be present under
homologous chromosome engines of the
genes may be same or different as I
mentioned before also
now the alleles can be same or it can be
different for example if an individual
has a bleep B so B maybe is for black
hair and small B is maybe suppose for
brown hair so this black hair and he
sees the value of the gene here right
similarly this one sees the value of
lynching hair so the alleys can be seen
I mean if the value also can be seen one
good maternal and paternal but it can be
different also they pair up with each
other during meiosis now the overdose
rows of during meiosis what happens
during meiosis that is what we see here
this it is has been seen that there is
some sort of combination even between
the whole locust chromosomes and that is
why if you would have observed that
sometimes in a kid he has some features
which are exactly similar to his father
he has some features which are exactly
similar to his mother but he also has
some features which are a mixture of
both or which are not present in of them
so those new features come up due to the
pairing of the oldest forms of Studio
noses so I mean if you remember the
process of meiosis that I am sure you
will remember how crossing over and
recombination takes place in meiosis
if not we will talk about crossing over
in a little while
whereas on the other hand if you talk
about sister chromatids so what is the
system
what step romantics and I think
about when the promos on duty means the
same roles on which I have drawn above
now these are the same all of the screws
now this ozone multiplicative send
giving the s-phase okay so this is how
it will become so then these two will be
sister format is right these to be the
sister from a kit and these two will be
duplicated all over scores so there will
be no movers today are still going to
cover all of the scholars of because
they are aware of the same size same
shape and everything so now you
understand sister chromatids are exact
copy of each other so this proposal and
this rose they an exact copy of each
other the values of the end is
everything has to be exactly identical
so they are sister chromatids but over
Lucas chromosomes they are like what is
that on the rules on one is maternal
chromosome they will have same sequence
of genes but it is not necessarily that
they will have the same value for those
genes so one it is just one half of a
duplicated chromosome so one half of it
it is formed during the synthesis phase
now before the synthesis phase the
proposal remains unmitigated somewhat
like this so this change happens during
the S phase or the synthesis phase of
interphase so that these are genetically
seems a genetically both of these are
exactly identical but if you talk about
the holos close up they are not
genetically identical that's what I was
talking about right they can be they can
have similes they can have different the
means to generate even they might not be
identical or they can be identical
sometimes but the sister chromatids will
always be genetically identical so I
will give you a live example let's
suppose like as I said that inside the
human body all the cells of our body
contains a total of 46 chromosomes
thanks so what is six chromosomes are
nothing but 23 pairs of homologous rows
now let us take an example
and understand that when I'm I need to
play alone and went over Lucas Cavazos
play alone so as I said this is step
four magnets help students and divisions
let us see how the head so these are the
total 46 chromosomes which are present
in the human body so they are basically
23 pairs of chromosomes if you look at
any one pair of Frozone you can actually
see two sets of chromosomes being
present so the one set has come from the
mother the other set has come from the
father right so these these are
homologous chromosomes these homologous
chromosomes are present inside a cell
all the time they're present all the
time because one is my channel and are
there is a channel so they have to be
present all the time but where are the
sister from against the sister from
annex a lot doesn't all the time now let
us suppose that you get a cut somewhere
in your finger what happens when you get
cut so what happens some of the sins I
mean your body uses some of the cells in
the nail so your body needs to repair
that part so for that what we happen new
cells will be formed how are you cells
formed by the process of cell division
now happens then division has to occur
what will happen the whatever spend
division has to occur what will happen
the chromatic will condensed from close
the chromosomes will duplicate sister
chromatids will be formed so sister
chromatids will be formed when extra
cells need to be formed by cell division
near that wooded area okay so simply we
shall will offer the sister chromatids
will play their role they perform they
may again have separated the new cells
will be function sister formattings
allowed me to stay permanently they are
going to get created as a part of the
process of cell division the ones the
cell divides the sister prometrics gift
I mean they get separated or they give
they belong different cells and that is
how new cells are formed so sister
chromatids are something temporary they
will they will be formed during the
course of the process and again they
themselves will later become the closed
zone for particular for a particular
self so there is keep coming
keep going but when you talk about
homologous chromosomes they are always
present inside the same so the 23 pairs
of homologous chromosomes are always
present inside the cells of our body so
that is how all those chromosomes and
sister chromatids and within from each
other so I think with this you have got
a fair idea about the structure of
chromosomes thank you please visit
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