5-7 Flowers

Look at the diagram of a flower.  Most flowers form as a series of rings.  The outer ring is made up of sepals.  Sepals are usually green and look like leaves attached to the stem at the base of the flower.  The colorful petals make up the next ring.  Inside the ring of petals, in the center of the flower, are the reproductive parts of the plant.  The stamens are the male reproductive organs.  Notice that each stamen has an anther on its tip.  This is where millions of tiny pollen grains are attached.  The solid tube called the pistil is the female part of the flower.  The pistil contains the ovary and egg/eggs.

The first step of fertilization is pollination.  Pollination is the movement of pollen from the anther to the sticky top of the pistil.  Birds and insects are responsible for pollinating many flowers.  They knock pollen off the anther and onto the pistil.  Rain and wind also aid in pollination.

After pollination, a tube grows out of the pollen grain that is stuck to the pistil.  Inside the pollen tube is the sperm.  The tube grows down into the ovule, which is at the bottom of the pistil and fertilization occurs.  The fertilized egg cell begins to divide and form a young organism called an embryo.  The ovule grows into a covering that protects what has now become a seed.  As this seed forms in the parent plant, the flower changes.  The sepals and petals die and fall off.  The ovule grows into a seed with a covering such as beans, berries, tomatoes, or the hard shells of nuts.  This covering protects the seed/seeds and also helps scatter the seeds.

When the fruit leaves the plant it starts to decay.  This allows the seeds inside to reach the soil where they can grow into new plants.  These seeds are sometimes pushed into the soil by rain.  Animals like squirrels and chipmunks bury seeds as well.

Look at the diagram of the seed.  When seeds are planted in soil they absorb water.  As temperatures become warmer the cells of the embryo inside the seed begin to divide, and the embryo grows.  The embryo continues to use the stored food within the seed and eventually breaks through the seed coat.  Roots sprout and it is now a new plant.  The sprouting of a new plant is called germination.

The roots of this new plant take in minerals and water to help it grow.  As the stem grows up, leaves begin to appear.  The leaves help the plant make its own food.  The plant becomes an adult plant that will develop flowers, flowers develop seeds, and the cycle begins again.

Directions: Answer the questions about seeds and flowers.

1. are found at the base of a flower.

2. The stamens are the reproductive organs.

3. Each stamen has an on its tip.  This is where millions of tiny grains are attached.

4. The pistil is the part of the flower.

5. The pistil contains the and the egg/eggs.

6. Pollination is the movement of pollen from the anther to the sticky top of the .

7. Fertilization occurs when a tube grows out of the pollen grain into the also called the ovary, and joins with an egg.

8. The fertilized egg cell begins to divide and form a young organism called an .

9. As the seed forms in the parent plant, the changes.

10. Animals like squirrels and chipmunks bury seeds, and they are sometimes pushed into the soil by .

11. The sprouting of a new plant is called .

12. Plant seeds come from

roots.

stems.

fruits and flowers.

None of the above.

13. The embryo grows by using the stored food in the

soil.

seed coat.

endosperm.

All of the above.

14. The roots of a new plant take in

sunlight.

minerals and water.

fruit.

None of the above.

15. The leaves of a plant make

air.

food.

nitrogen.

All of the above.