Science material to study for our upcoming Quiz on Wednesday and for our Test
next week: (Please help your child with study this material as well as whatever
else we have covered in class).
Roots anchor plants in place, seek out and store moisture and nutrients for the
plant. Two types of root systems: tap roots ( dandelion root, carrot, turnip- it is a
long, thick root that grown down deep and straight) and fibrous root (grass, most
potted plants – they have many root tips and they spread out in all directions)
Stem: The plant stem transport water and other nutrients from the roots to the
leaves. The stem also carries the food made in the leaves to all parts of the
plant.
Leaves make food for the plant to live and grow. They are filled with chlorophyll
(the substance that gives plants their green colour), which is necessary for
photosynthesis to occur.
Sepal: leaflike covering of the flower bud found just under the flower and above
the stem.
Stages in the life cycle of a plant: Seed, seedling, adult plant, adult plant with
flowers, adult plant with fruit and back to seed.
Seed Dispersal:
Plants spread their seeds in different ways: by wind, by water, by force, by
animals (either fur or poop).
Maples and dandelions spread their seeds by wind. The maple seeds have wings
called samaras that make them flutter in the breeze as they fall from the trees
like tiny helicopters.
Coconuts and lotus spread their seeds by water.
Geraniums and Impatiens spread their seeds by force.
Animals eat the berries and then poop out the seeds and if the seeds fall on good
soil, then a new berry plant grows there. Sometimes the seeds get caught on the
animals’ fur and the animals then carry the seeds to new places like raspberry
seeds. Also sometimes, squirrels forget where they buried the acorns (seeds of
the oak tree) in the Fall.
How Plants help us and how we help plants:
1) We breathe in oxygen and breathe out carbon dioxide. Plants breathe in
carbon dioxide and breathe out oxygen.
2) We get wood from trees. We use the wood from the trees to make
furniture, toothpicks, doors, closets, pencils, toys, games, rulers, clothes
pegs and many other things.
3) We get cotton from the cotton plant and we use it to make our clothes.
4) We use the latex that we get from the trees to make rubber which we then
use to make tires for our cars. We also use latex from trees to make
chewing gum. Latex is the milky white liquid that oozes out from a tree
when it is injured. Latex is not sap.
5) Trees also give us bark which we use to make paper.
6) We also get our food from plants: all our fruits and vegetables are from
plants.
7) We also get essential oils from herbs: essential oil of lavender, clove.
8) We use plants to make herbal remedies and medicines, soaps and
shampoos and deodorants, toothpaste, skin creams, painkillers.
Herbal
remedies
Sage and
thyme are
used in herbal
remedies.
Medicines
Garlic is
used to
treat heart
disease.
Ginger is
used to
treat
arthritis.
Cranberry
juice is
used to
treat urinary
infections.
Echinacea
plants are
used to
treat the
cold and flu.
Soaps,
Shampoos
Oils that
come from
jojoba, tea
tree,
almond,
grapseed
and
coconut are
used to
make
soaps and
shampoos.
Toothpaste
Plant extracts
from tea tree
oil, mint,
chamomile,
sage and tea
tree are used
in toothpaste.
Skin
Cream
Dried aloe
vera is
used in
skin
creams.
Sandalwoo
d and tea
tree oil are
used in
skin
creams.
Painkillers
Aspirin is
obtained from
the white
willow tree
and is a
painkiller.
Life Cycle of a Flowering Plant:
First we plant the seed, then the little seedling grows, then it forms a bud and
then the bud turns into a flower and then the flower dies.
Pollination
What is pollination?:
A flowering plant is mature when it has finished growing. The flower blooms
when it is ready to reproduce. The stamen is the male part of the flower and it
produces pollen. The pistil is the female part of the flower. At the top of the pistil
is the stigma. The pistil has an ovary at its bottom and the ovary contains ovules
or female cells. Pollination takes place when pollen is deposited (put on) the
stigma of a flower of the same type of plant. Then the pollen travels in a pollen
tube and meets the ovule to form a seed. If the ovary has only one ovule, then
only one seed is formed. Examples are: mango and avocado, peach. If the
ovary has many ovules, then many seeds are formed. Examples are: melons,
apples, pears. Then the petals of the flower fade , the flower dies and the ovary
grows around the seed to form the fruit.
What are the different ways that pollination can take place?
Insects and birds: Bees, moths, butterflies, flies and hummingbirds drink nectar
from the attractive, sweet smelling flowers. The pollen gets onto their legs and
they then go to another flower of the same type of plant for some more nectar
and the pollen from their legs get deposited on the stigma of the flower.
Wind: Wind carries the pollen of flowers of rice, corn, wheat and barley. The
pollen of these plants are lighter and their flowers are not attractive nor are they
sweet smelling.
Self-Pollination: Some flowers self-pollinate. For them to self-pollinate, their
pistils have to be very close to their stigmas.
Why do leaves change colour?
It gets cold, the leaves lose their chlorophyll and so you can see the orange and
yellow. They get red because of the extra glucose and they get brown because
of waste matter. The plant survives the winter because of the food stored in the
stem and branches. Pine leaves do not fall off because they are stronger as they
are bunched up and they have a waxy coating that makes them winter proof.
Maple leaves are lighter and so they fall in the Fall.
Photosynthesis:
Photosynthesis is the process by which leaves make food for the plant. The
plant breathes in carbon dioxide and the carbon dioxide combines with the water
and the chlorophyll ( the chemical in the leaf that gives it the green colour) and
the light energy from the sun to produce glucose (sugar) and oxygen. That is
how the plant breathes out oxygen. The glucose is the food that the leaves have
made. In the Fall, when the weather gets colder, the glucose is stored in the
stem, roots and branches of the plant throughout the winter.