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this segment is concerned solely with
point for you
struck so cookies
populistic peace
for the identification
of organisms
so it's finding organism that needs identified
suppose you are out doing
study of
people into pond or lake
and found this
closing
as a result of maybe runoff
from afar
and your job posting identified
the species
that you're looking at
so that you can go ahead and write
report of what's going on
your first
is likely to be done
take a sample of it to the lab and look at it
with a microscope
when you look in there
your lately
this
this should tell you that you are looking
provided that you've got some
basic knowledge
what you're doing
algae have
chloroplasts in their cells
possible green
used in photosynthesis
this
particular algae that we have
is made up of long
on brand filaments
with this
basic information in mind
our next step
in identification
is set
ki
see if you could figure out how it works just by looking at it
course is a very simple
version of
orthodontic awesome uske
the content of this
is adapted from this you are out here
at the point
so if you have a look
maybe you figured out how it works
but this is how it works if you have any trouble
the key dichotomous key is made up of ah...
series of statements
set of statements
is deemed dividing
the big group
into
smaller rooms
so that you can eventually zero in on the identity of the unknown species that
you're trying to
identify
for instance what we found in the pawn
microscopic
it's not microscopic we needed a microscope to see details of it
the first statement
or peer statements
which is why beginning
dichotomous branching into two
pero statements
says microscopic or microscopic
our response should be that it's a microscopic
so that
means that we are directed
to go to
number two
which then asks
does it contain chloroplasts ornoff and it doenst contain chloroplasts
so we go to three
and in three
are the cells solitary which means just by themselves
or or the in
colonies
or are these filamentous
what we might not be sure about what the column he is
but if it's grouped with solitary we've already identified that
ecology is filamentous
that texas two five
long
unabashed
filaments
on brach filaments
so that
over two seven
at seven
were asked by the chloroplast in
spiral into spring
or are they not him spiraling we don't have any evidence that they rent spiral
so that means instead eight
do we have a single chloroplasts or many small chloroplasts
you can see here
are specimen has many small or lives
and that leads us
to identify our specimen
as
barracks
and this is how you used
a simple dichotomous key
how do you should go you
are likely to be asking
why
why do you need
go through this system when maybe you could just look through the pages of the
book for
go online search for kinds of policies
and that could very well work
you just have maybe fifty tens of thousands of people from
that could certainly work
or maybe even a hundred
but if you had eight thousand
species
and more
apology
it could be the big time consuming
think about looking for somebody in a town with
ke thousand homes
it would take some time to carry out your search
bus if u
had some important information about who we were looking for
each time you ask the question
if somebody
it narrowed your search down
then it will be a whole lot needs you
so this is what
a dichotomous key does
it takes
information that you know simple information that includes ears
and in very quickly the laws you
to move
toward identifying
name
of what you have in front of you
trying to
figueroa
uh... the keys
are usually made by biologist
for biologists
so in the real world of biology in trying to identify things
definitely and asset if you have a
basic knowledge of some of the terms
the pictures
we've used here to understand the key like
microscopic and briscoe etc
to your chloroplasts far
to know what
filamentous means uh...
what solitary and colonial mean
will also be helpful
so of basic understanding
of the structure
of what you're looking at
certainly is helpful
because
ultimately to identified we have to work with things that are pc to observed
is no point talking about things that are
really complicated and hard to see
we would like to at quickly identify welfare looking at
so let's stop here now and have
a look at your activity
directivity requires you to make a key for
eight organisms that
hopefully very familiar with a
scorpion
said to be
dragonfly ladybug spiders and butterflies
so go ahead
look back act
asap okie
look at how it's made up
pairs of statements
and tried to organize
art eight
specimens here
n_p_r_'s euro
and hints
is to look for features like
body segments
wings and legs
yes that is easy to observe and would be very useful
in separating
the members of this group
your answer doesn't have to
exactly match this to be right
so you could have a very good answer that
does not match this and if you have it
totally wrong and you think you need to another shot at this
cruelty refrigerator
t_l_c_
vegetables or seafood items
and try making a key to identify the needs
of what you have in the refrigerator
for maybe for the purpose of the sun
alien being that you have stayed with him
wool buildings of of what's in the refrigerator
but the night the ill-fated flight
some of the features