4.- PLANTS
INDEX:
4.1. Characteristics of plants.
4.2.- Parts of plants.
4.3.- Groups of plants.
4.4.- Plant nutrition.
4.5.- Plant reproduction.
4.1.- Characteristics of plants
- They are multicellular organisms.
- They cannot move
around.
- They make their own food.
- Almost all plants live on land. Some are
aquatic.
They
have three parts:
- Roots:
hold the plants in the ground and give them water and mineral salts.
- Stem:
Give the plants shape.
- Leaves:
make their food.
4.3.- Groups of plants
There are two groups of plants:
- Plants without flowers. These plants do not have flowers or seeds. They
reproduce
with spores.
- Plants
with flowers. These plants reproduce with seeds.
According to their size, We can classify plants with flowers into three groups: trees,
shrubs and grasses.
|
SIZE
|
STEM
|
BRANCHES
|
AGE
|
TREES
|
They are
Large
|
They have
Woody, hard
stems called trunks
|
They come from the trunk.
|
They live many years.
|
SHRUBS
|
They are
Medium-sized
|
They have woody, soft and thin trunks
|
The branches come from the ground.
|
They live many years.
|
GRASSES
|
They are
Small.
|
They have non-woody stems that are soft and
flexible stem.
|
They have no branches or leaves.
|
They live a few months.
|
4.4.-
Plant nutrition.
Plants have three stages in their nutrition:
1.Getting
nutrients:
- Plants get Carbon dioxide from the air through their leaves.
- Plants get water and mineral salts from the soil through their roots.
This mixture is called Xylem sap.
2. Making food:
- Photosynthesis is the process of plants making their own food and
producing oxygen. During this
process, the green substance (called chlorophyll) in leaves catches the
sunlight.
- The
xylem sap (water + mineral salts) goes up the stem to the leaves through tubes called xylem vessels.
3.
Transporting food:
- The leaves transport the phloem sap throughout the
plants: roots, stem, flowers and other leaves.
4.5.-
Plants reproduction.
-
Plants with flowers have reproductive
organs:
·
Stamens are the male reproductive
orgnas. They have round sacs that produce pollen.
·
Pistill
is the female reproductive organ. It has a bottle shape with ovules inside.
·
Corolla. It is made up of a group of
coloured sepals and petals.
·
Calyx: It is a group of small leaves
called sepals.
Plants carry out reproduction to make
new plants that are similar. Stages in the reproduction:
1.Pollination: Grains of pollen are transported from the stamens to the pistil.
2.
Fertilisation: In the pistil, the grain of pollen joins an ovule.
3.
Fruit is a fertilized ovule and it has seeds inside.
4.
Germination: The seeds grow into a new plant.
-
Plants without flowers reproduce by spores.
Spores are special cells that germinate and grow into a new plant.
ACTIVITIES ________________________________________________
1.- Write a sentence with these words.
·
Can´t move around – make their own food – roots, stem
and leaves
·
With flowers – without flowers
·
Trees – shrubs - grasses
2.- What are the three stages of plant nutirition?
3.- Match the substances to the parts of the plants that transport them.
Xylem sap roots
Phloem sap phloem
vessels
Mineral salts and water xylem vessels
4.- Complete the sentences.
·
Plants can be plants with ___________ or
plants without _____________ .
·
The parts of a flower are: _______, ___________,
____________, and _____________ .
·
Pollination causes ________________ .
·
Seeds
____________ and grow into a new plant.
·
Plants with flowers reproduce with
________________ .
·
Plants without flowers reproduce by
_______________ .
5.- Write the stages of reproduction in
order: fruit formation, pollination, germination, fertilization.