Key Differences Between Monocots and Dicots: Structure and Growth

hi everyone tonight's video is on two different types of angiosperm called monocots and eudicots or eudicots can be

abbreviated dicots and that's how i am going to refer to them in this video monocots and dicots differ in structure

and growth patterns and we're going to go through each of these example mono cause are grass and lilies i bet you

didn't know that grass was a flowering plant but in fact if you don't mow the lawn it will form flowers not what you

think of as flowers but it does form a flower reproductive structure an example dicot would be a rose or even your apple

trees so first I want to go through some just basic flowering plant structure of course you know that this would be an

angiosperm because you can see the flower anything in any plant that we see above ground we refer to as the chute

system any structures that are below ground are the root system when I'm talking about the differences in

structures between monocots and dicots we are going to see that there are differences in the leaves that there are

differences in the root system there are difference in the flower structure and there's also differences in the vascular

structure and the first leaves that are produced by the plant when it's initially germinating so let's go

through each of these differences the first difference is in the first leaf that is produced by the plant when it

first sprouts from the ground that first leaf is called a cotyledon and the caught part of monocot is short for

cotyledon if you look at a monocot when it first emerges from the ground it just has one leaf coming straight up if you

looked at the seed of a monocot you would see that the embryo inside the seed in addition to having the endosperm

would have an embryonic plant with just one cotyledon when you see a dicot sprouting from the ground it initially

comes up and opens up with two four leaves or two cotyledons which is where the term dicot comes from if you look at

a dicot seed you would of course see the large endosperm and you would see the embryonic plant with two cotyledons

or two first leaves the structure of the vascular system in the stems and leaves also differs between monocots and dicots

so if we look at the vascular system of a plant remember you have water being transported in this eylem and sugars

being transported in the phloem if we look more up-close at what the structures of these two transport

systems look like the phloem is composed of living cells and it transports sugars made in the leaves to all parts of the

plant and the fluid moves in both directions both up and down if you look at the xylem it is composed of tubes of

dead cells that are lined with lignin and that is our molecule that remains a rigid structure and allows plants to

grow upright as if they had bones even though they don't have bones the xylem transports water and dissolved minerals

from one in one direction only from their roots all the way up to the leaves so material only moves in that one

direction the arrangement of the xylem and phloem in the stems is different in monocots and dicots if we look at a die

cut and we do a cross-section through a stem what you'll see is there's a wagon wheel of bundles and the green part of

this bundle is the xylem and the little purple part on the tip of each of these bundles is the phloem and you can see

that it's very organized in this wagon wheel structure xylem phloem on the outside its eylem on the inside the

phloem on the outside all around the edge of this dicot stem if you look at a monocot stem it just looks like someone

through these vascular bundles down in a random order it's very disorganized each of these

purple structures is a combination of xylem and phloem but they are placed randomly throughout the stem

if you look at the leaf structure of monocots and dicots you will see a distinct difference

first of all in monocots you tend to see a long narrow leaf and if you look closely you can see these veins which

are actually bundles of xylem and phloem are arranged in parallel you never see anything other than parallel veins if

you look at a dicot leaf first of all it's very broad it's much wider than a monocot leaf and if you look at the

veins they have more of a web-like pattern now this is where some students get a bit confused because if you look

closely at these vein patterns in this dike lot leaf you would say well this vein is parallel to this one so it has

parallel veins and yes that's true but it also has many other veins coming off of these parallel veins giving it more

of a web-like pattern in a monocot you only see mono parallel veins you don't see any web-like pattern at all if we

were to look at the root structure of monocots and dicots you would see a drastic difference in a dicot you see

what's called a large tap root the center root is this big fat root which has some small roots coming off it if

you're out in the garden weeding and you get a weed and you're pulling and pulling it it just won't come up and I

almost guarantee that that is a dicot because those tap roots can be really difficult to remove and they can go very

deep into the soil monocots on the other hand have these fibrous root systems that often don't go as deep this picture

can be a little bit misleading but you don't see any one central root system and you can pull them up quite easily

when you're pulling monocot weeds in the garden the flower structure differs dramatically between our two types of

flowering plants in a monocot the flowers have petals in multiples of three so you can see you have one two

three four five six therefore this is a monocot one two three four five six again this is another monocot and if you

look closely at these pictures you can also see that this has a long narrow leaf and again

long narrow leaf so that would be your second clue that this is a monocot if he could look even closer at these leaves

you would see parallel vein structures in a dicot you see flowers in petals of multiples of four or five so here we

have one two three four five petals makes it a dicot here we have four petals also makes it an icon again look

closely at this picture and you see a broad leaf in each case which is different from these long narrow leaves

in the monocot if you were to look even closer you could see a web-like pattern of the veins in these leaves so in

summary the differences between monocots and dicots which are two types of angiosperms are in their first leaf or

cotyledons they have a different vascular system it's random in the monocot and it's organized like a wagon

wheel in the daikon the leaf structure in the monocot is very narrow with parallel veins in the daikon it's a

broad leaf with web-like veins the root structure in a monocot is a web-like structure with no large central root the

root structure in a dicot has a large central tap root the flower structure in a monocot the petals are in multiples of

three and in a dicot those petals are in multiples of four or five you should know these differences between monocots

and dicots and if given a picture of a leaf or a plant a whole plant or the flower or just the roots you should be

able to identify it as a monocot or a dicot you should also be able to state at least one example of a monocot

angiosperm and a dicot angiosperm that you know from your life that's all for tonight