MONTESSORI INTEGRATED SCHOOL
SECOND QUARTER
SCIENCE 5&6
SUPPLEMENT 4A
NAME: _____________________________________ SECTION: _________ DATE: ___________
THE STEM
MAIN FUNCTION OF THE STEM
Since the leaves need the sun to make their food and there is great
competition for the plants on the ground, the stem has the job of taking the plants
to find the light that enables them to make food.
The stem takes the plant up, and the roots have the tendency to grow
downward. The stem has the tendency to grow upward. In this way, the stem may
carry the leaves towards the light it needs.
The stem has another job. It carries water and nutrients from the roots up
to the leaves so the leaves can make their own food. It also brings dissolved food
from the leaves to the other parts of the plant. The stem also holds the leaves and
the flowers.
TWO KINDS OF STEM
1. Herbaceous stem comes from the Latin word
“herba” meaning grass. The stem is soft and
succulent. Examples would be the stems of vegetables.
2. Woody stems grow very tall and live for a very long
time. Examples
would be the stems of trees.
Parts of Woody Stem
Since the leaves
need water in
order to make food, water is carried up to the stem with
tubes in them that have to be protected, so the plants
develop a layer called bark. As these tubes grow, the stem
thickens, and this develops rings. Every year the plant adds a
new set of rings and this is how we can tell the age of the
tree.
As the tree grows old, the tube at the center hardens and
the living part of the new tubes move to the outer part of the stem. This means that the living
part of the stem is just inside the bark.
The innermost part of the stem is hardened tubes. This is where we get our food. They
are very strong and provide support for the tree. The wood is also elastic. When the wind blows
the tree will sway and bend.
KINDS OF TUBES
We know that the tube brings water up to the leaves and brings food to the leaves.
These are found inside the bark.
1. Phloem comes from the Greek word “Ploos”
meaning bark. They carry food and they bring food to
the tree.
2. Xylem comes from the Greek word “Xulom”
meaning wood. This is found inside the part of the
stem closer to the wood part. They carry water from
the roots up to the leaves.
3. Cambium comes from the Latin word “Cambiarre”
meaning exchange. This is found at the center of the
tube between the phloem and xylem.
VARIETIES OF STEM
When animals get hungry, they go through
the bark of trees. They eat the soft and juicy part
of the plants. Sometimes when the weather is too
bad, some plants decide to grow underground for
protection, we call these underground stems. But
not all underground stems are alike, an onion is an
underground stem we call a bulb.
Another is a tulip. It has succulent and soft leaves.
The corm has short-flaky bulb-like stems. The
rhizome is just like ginger. It has a root-like stem
that senses leafy shoots from the outer surface
and produces roots from the lower side. Next are
tubers, they are short-flaky underground stems
which bear tiny scale-like leaves at the axle.
Examples: white potato, and anemones.
Some stems grow erect and tall; they are called erect stems. Stems that
grow on the ground seem lazy; they are called procumbent stems. The stem that
is lying flat with the tip growing upwards is called the decumbent stem.
Do you know that stolons, sometimes also called runners? They are
slender, elongated horizontal stems that grow above ground. Next, we have the
climbing stem but not all are alike. We have stems that twine around the branch. We call them
a twining stem so they can bring leaves towards the sun. An example of this is honeysuckle.
Another, just hook on towards other branches and they are called hook climbers.
How does the twining stem climb up to another stem? It makes use of their tendrils.
Tendrils help the plant reach out in order to climb towards the sun. Examples of this are grapes,
ampalaya, patola.
THE FLOWERS
STORY OF THE MAIN FUNCTION OF THE FLOWER
There was a flower which has a label like a restaurant that
attracts hungry insects because of its fragrance and physical
appearance. The insect goes directly to the nectar of the flower-like
hungry humans wanting to eat a new food. Sometimes this tends to sip
the nectar of just one flower. But then again it will look for other flowers
to sip more nectars. In doing so, this bee carries some part of the flower
to the next flower it will visit. This is how bees would go from one
flower to another much like hungry humans will transfer from
restaurant to restaurant in search of new places to eat.
PARTS OF THE FLOWER
1. Corolla is the part of the flower that calls to insects. It
comes from the Latin word which means “crown”.
2. The flower bud is protected by the calyx which is the Latin
word meaning “bulb”. The calyx is made up of sepals.
3. Stamen is the part of the flower that makes the pollen.
This is the male part of the flower. It comes from a Latin
word meaning “thread. The stamen has anther.
4. The filament holds up the anther.
5. Stigma is the sticky and topmost part of the pistil that
catches the pollen.
6. The part that holds the stigma is called style.
7. The pistil houses the ovary. The ovary contains ovules.
Ovules become the seed.
VARIETIES OF THE PARTS
Do you know that there are two kinds of flowers according to
a corolla?
a. Gamopetalous is a flower that has joined petals and an example of
this is the petunias.
b. Polypetalous is a flower whose petals are not joined
and the examples of this are Santan and
rose.
We also have different kinds of flowers according to
the calyx.
1. Polysepalous is a flower in which the calyxes are not
joined.
2. Gamosepalous is a flower in which the calyx is joined
a little bit.
FLOWER TYPES
a. Incomplete /Imperfect Flower
A flower that has either all male parts or all female parts, but not both in the same
flower. Examples: cucumbers, pumpkin, and melons.
b. Complete/Perfect Flower
A
flower that has both the male parts and female parts in the same flower. Examples: roses, lilies,
and dandelions.