Download Plants grow in every part of the world –primary

Parts of a Flower
Plants grow is every part of the world- mountaintops, oceans,
deserts, and Polar Regions. Without plants there would be no life
on earth. They provide the air we breathe and the food humans
and other animals eat. Plants also supply us with many useful
products (something that comes from the consequence of
something else.) such as lumber for wood and paper and cotton
fibers for clothes.
Scientist believe there are more than 350,000 species
(individuals that may resemble (look like) one another). Their size
varies from barely visible plants that grow on a forest
floor to the largest living life forms on Earth like the giant
sequoia trees of California.
Giant sequoia trees
Plants are also the oldest living things on Earth. One kind of pine
tree in California called the bristlecone pine started growing
4,000-5,000 years ago.
Bristlecone pine trees
Today for Science Lab will be observing the part of the plant
called the flower. Flowers are the part of a plant that makes
seeds.
PARTS OF A FLOWER
A flower has two special parts that help the flower make seeds.
These two special parts are the male stamen and the female
carpel. A stamen has two parts to it, the A anther or pollen box
and the filament.
The carpel has three important parts. At the top is a sticky tip
called the stigma. The long stem is called the style. At the very
bottom is the ovary. The ovary has eggs in it that can grow into
seeds. A pollen grain needs to join with each egg to form a seed.
Most flowering plants need to get pollen from another plant. This
is called cross-pollination. In some flowering plants, the pollen
grains are blown from one plant to another by the wind. Grains
such as wheat, rice, corn oats, and barley have flowers that are
pollinated by the wind.
Wheat Plants
Some flowers are pollinated by insects. These flowers often have
bright colors and sweet nectar to attract insects such as bees or
butterflies. When the insect visits a flower, the pollen sticks
onto its body. When the insect visits another flower, the pollen
brushes off onto the sticky stigma of the flower.
Bee collecting pollen from flower
Some flowers can grow fruit and seeds without being pollinated
at all. Dandelions plants can grow fruit and seeds without being
pollinated.
Dandelion
Flowers pollinated by butterflies usually bloom in later summer
when the butterflies are around. Flowers that have a
strong scent or smell in the evening such as honeysuckle are
pollinated by night –flying moths.
Honeysuckle flower
Yucca plant and flower
So are a number of pale flowers, such as the yucca flower.
Growing seeds and fruit
What happens when the pollen grain gets onto the sticky stigma?
If the pollen grain comes from a different kind of plant, nothing
happens. But if the pollen comes from the same kind of flowering
plant, then two things happen. First, part of the pollen grain
grows a tube down through the stigma and style to the ovary,
where the egg is. Then the center part of the pollen grain goes
down the tube and joins with the egg. This joining is called
fertilization. A seed can now form.
Some flowers, such as apple, pear, and strawberry flowers have
many stigmas in each flower and so have many ovaries. If pollen
grains stick to each stigma, then several seeds will grow inside
the apple or fruit.
Apple blossoms
Apple fruits with seeds
All flowering plants have fruit. Plants such as daffodils and roses
have fruit but it is not the kind of fruit we eat.
While the seeds and fruits are growing, the sepals, petals, and
stamen of the flower die. On some fruit such as apples, pears,
and string beans, you can see the shriveled –up sepals, petals or
stamens on the end of the fruit.
Can you see the dead flowers on the ends of these apples?
PARTS OF A FLOWER LAB
Teachers: Read directions to students when they begin the
lab
Procedure:
Objective: Students will identify the parts of a flower to
discover where seeds originate.
Materials:
 Complete flower
 Flower Dissection Instructions (one set per tray) and Parts
of a Flower Data Sheet (One per student)
 Clear tape ( one roll per tray)
 Magnifier
 Cut apple (one per tray)
 How Flowers Reproduce Diagram (One per tray)
Activity:
 Inform students that they are going to dissect (take apart)
a flower to see where seeds are formed.
 Students follow the instructions on the data sheets to
dissect their flowers (one flower per two students).
Complete the data sheet.
 When the data sheet is complete have students read the
information of the How Flowers Reproduce work sheet.
Parts of a flower Data Sheet:
Directions: Tape or draw (Since there is just one stamen one students
should draw that stamen and the other student tape the stamen in the
correct box.) the parts of a flower in the correct boxes below then
complete the information.
Stem
Description:
Magnified view of the tip of the
stem
Sepal
Number of
sepals:__________________
Description of how it feels:
Petal:
Describe fragrance:
Pollen:
Describe how it feels:
Number of
petals:__________________
Why do flowers have colored petals
and sometimes have a fragrance?
Magnified view of pollen grains:
Stamen:
Number of
stamens:__________________
Describe what you saw on the
anther:
Pistil:
Number of
pistils:___________________
Describe how the stigma feels:
Magnified view of anther:
Magnified view inside ovary:
How Flowers Reproduce
1. Each pollen grain is a single cell. Pollen forms on the top (anther) of the
stamen.
2. Pollen is carried by insects, wind, or birds to the stigma, the sticky part top of
the plant.
3. Once on the stigma, the pollen grain absorbs moisture from the pistil and
breaks open.
4. Its contents form a pollen tube, growing down the pistil.
5. The pollen tube grows until it reaches the ovule containing an egg cell.
6. Sperm from the pollen travels down the tube to the ovule and unites with the
egg cell.
7. A seed now begins to develop inside the ovary.
8. An ovary may have a single seed or more than one seed.
9. The ovary develops into a fruit enclosing the seed(s).