Download 2 Reproduction of Flowering Plants

Name
CHAPTER 13
Class
Date
Plant Processes
SECTION
2 Reproduction of Flowering Plants
National Science
Education Standards
BEFORE YOU READ
After you read this section, you should be able to answer
these questions:
LS 1a, 2a, 2b, 2d, 5b
• What are pollination and fertilization?
• How do seeds and fruits form?
• How can flowering plants reproduce asexually?
What Are Pollination and Fertilization?
Flowering plants are most noticeable to us when they
are in bloom. As flowers bloom, they surround us with
bright colors and sweet fragrances. However, flowers are
not just for us to enjoy. They are the structures for sexual
reproduction in flowering plants. Pollination and fertilization take place in flowers.
STUDY TIP
Summarize As you read,
write out or draw the steps of
pollination and fertilization.
Pollination and Fertilization
1 Pollen grains land on the stigma
and begin to grow pollen tubes.
Stigma
Pollen
tube
Anther
Pollen
Sperm
Style
Ovary
TAKE A LOOK
Ovary
Ovule
Ovule
containing
egg
2 Sperm travel down
pollen tubes and
fertilize the eggs.
1. Identify Circle the part of
the flower where pollination
occurs.
2. Identify Draw an arrow
to show where fertilization
will take place.
Sexual reproduction begins in flowers when wind
or animals move pollen from one flower to another.
Pollination occurs when pollen from an anther lands
on a stigma. Each pollen grain grows a tube through the
style to the ovary. The ovary has ovules, each of which
contains an egg. Fertilization occurs when a sperm joins
with the egg inside an ovule.
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Plant Processes
Name
SECTION 2
Class
Date
Reproduction of Flowering Plants continued
What Happens After Fertilization?
a A mature plant produces a flower.
Pollination and fertilization take place.
b After fertilization,
each ovule within
the ovary contains a
fertilized egg.
STANDARDS CHECK
LS 2a Reproduction is a
characteristic of all living systems; because no living organism lives forever, reproduction is
essential to the continuation of
every species. Some organisms
reproduce asexually. Others reproduce sexually.
Ovary
3. Explain Where do seeds
and fruits come from?
Ovule
c Petals and
stamens
fall away.
e Each seed contains
TAKE A LOOK
4. Identify In step C,
circle the structures that will
become seeds.
a tiny plant. If a
seed sprouts, or
begins to grow,
it can become a
new plant.
d The ovary becomes the
fruit, and each ovule
becomes a seed. After
the fruit ripens, seeds
are dispersed.
THE FUNCTIONS OF FRUITS
READING CHECK
5. List What are two
functions of a fruit?
When people think of fruit, they often think of apples
or bananas. However, many things we call vegetables,
such as tomatoes or green beans, are also fruits! A fruit is
the ovary of the flower that has grown larger.
Fruits have two major functions. They protect seeds
while the seeds develop. Fruits also help a plant spread
its seeds to new environments. For example, an animal
might eat a fruit and drop the seeds far from the parent
plant. Fruits such as burrs spread when they get caught
in an animal’s fur. Other fruits are carried to new places
by the wind or even by water.
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SECTION 2
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Reproduction of Flowering Plants continued
How Do Seeds Grow into New Plants?
The new plant inside a seed, called the embryo, stops
growing once the seed is fully developed. However, the
seed might not sprout right away. To sprout, most seeds
need water, air, and warm temperatures. A seed might
become dormant, or inactive, if the conditions are not
right for a new plant to grow. For example, if the environment is too cold or too dry, a young plant will not survive.
Dormant seeds often survive for long periods of time
during droughts or freezing weather. Some seeds actually
need extreme conditions, such as cold winters or forest
fires, to germinate, or sprout.
READING CHECK
6. Explain Why would a
seed become dormant?
Seeds grow into new plants. First,
the roots begin to grow. Then, the
shoots grow up through the soil.
TAKE A LOOK
7. Identify Which part of a
new plant grows first?
How Else Can Flowering Plants Reproduce?
Flowering plants can also reproduce asexually, or without
flowers. In asexual reproduction, sperm and eggs do not join.
A new plant grows from a plant part such as a root or stem.
These plant parts include plantlets, tubers, and runners.
Three Structures for Asexual Reproduction
Critical Thinking
8. Infer When would asexual
reproduction be important
for the survival of a flowering
plant?
Kalanchoe produces
plantlets along the
edges of their leaves.
The plantlets will fall off
and take root in the soil.
A potato is a tuber, or
underground stem. The
“eyes” of potatoes are
buds that can grow into
new plants.
The strawberry plant
produces runners, or
stems that grow along
the ground. Buds along
the runners take root
and grow into new
plants.
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Plant Processes
Name
Class
Section 2 Review
Date
NSES
LS 1a, 2a, 2b, 2d, 5b
SECTION VOCABULARY
dormant describes the inactive state of a
seed or other plant part when conditions are
unfavorable to growth
1. Apply Concepts Is fertilization part of asexual reproduction or sexual reproduction?
Explain your answer.
2. Compare What is the difference between pollination and fertilization?
3. Summarize Complete the Process Chart below to summarize how sexual
reproduction produces new plants.
A mature plant produces flowers.
Eggs are fertilized.
4. Identify Name two environmental conditions that can cause a seed to become
dormant.
5. List What are three structures a flowering plant can use to reproduce asexually?
6. Infer Why do you think roots are the first part of a plant to grow?
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Life Science Answer Key continued
8. If no other plant of the same species were
2. Taproot systems have one main root that
available for pollination, a plant could still
reproduce, asexually.
can get water from deep underground.
Fibrous root systems have many small roots
that get water from close to the soil surface.
3. Stems support the body of a plant; allow for
transport of water, minerals, and food; and
store materials for the plant.
4. roots, stems, leaves, flowers
Review
1. Sexual—it involves the joining of a sperm
and an egg.
2. In pollination, pollen lands on the stigma. In
Chapter 13 Plant Processes
3.
SECTION 1 PHOTOSYNTHESIS
1.
2.
3.
4.
a green pigment that absorbs light energy
in the grana of chloroplasts
glucose and oxygen
mitochondria
5. The plant couldn’t take in carbon dioxide. It
couldn’t make food.
6. Circles should be around the structures on
the sides of the stoma; they open and close
stomata.
7. chemical energy
4.
5.
6.
SECTION 3 PLANT RESPONSES TO THE
ENVIRONMENT
Review
1. It reflects the green wavelengths of sunlight.
2. Mitochondria break down food to provide
1. anything that causes a reaction in your body
2. The X should be on the right side of the
energy. They take part in cellular respiration.
3.
Photosynthesis
Cellular respiration
Cells make food for the
plant.
Cells break down food to
provide energy.
Oxygen is produced.
Oxygen is used to break
down food.
3.
4.
5.
6.
7.
4. stomata and cuticle
5. They form the base of almost all food chains
on Earth. They also produce oxygen, which
most organisms need for cellular respiration.
6. They would lose too much water.
2.
1. stigma
2. ovule
3. Seeds are fertilized ovules. Fruits are ovaries
6.
7.
picture. A plant will grow toward light.
Arrow points down.
It must have been growing upside down.
Plant stems grow away from gravity.
7.2 h
chlorophyll
orange and yellow pigments
Review
1. A negative tropism is growth away from
SECTION 2 REPRODUCTION OF
FLOWERING PLANTS
4.
5.
fertilization, a sperm joins with an egg.
A mature plant produces flowers.
Flowers are pollinated.
Eggs are fertilized.
The ovary becomes a fruit, and ovules
become seeds.
Seeds are spread. They sprout and grow into
new plants.
very cold weather, very dry weather
plantlets, tubers, runners
Plants need roots first so they can start to
get nutrients from the soil. Also, the roots
hold the plant in place.
3.
4.
5.
that have grown larger to protect the seeds.
The ovules should be circled.
Protect the seed and spread seeds to new
environments.
if conditions were not right for a new plant
to grow
the root
6.
7.
a stimulus. A positive tropism is growth
toward a stimulus.
Cells farthest from the light grow longer
than cells facing the light. This causes the
shoot to bend toward the light.
plant growth in response to gravity
change in the length of days
Short-day plants need short days and long
nights in order to start reproducing. Long-day
plants need longer day lengths to reproduce.
Chlorophyll hides the other pigments in the
summer.
Evergreen leaves are covered with a thick
cuticle that protects them from cold and dry
weather.
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Interactive Textbook Answer Key
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Life Science