Transcript Reproduction of Seedless Plants: (p.100-101)

How Do Plants Reproduce?
Chapter 3 Lesson 2
Reproduction of Seedless Plants: (p.100-101)
• Nonvascular (mosses) and vascular
(ferns) reproduce in the same way.
– 1) Gametophyte generation – Plants
form gametes which are male and
female cells. This forms a new plant.
• When male and female gametes join
together, they form a zygote.
• This process is known as fertilization.
• A fertilized egg grows into a
sporophyte.
– 2) Sporophyte generation – The
plants form spores, a single cell that
can be carried to a new location by
wind or water and grow into a new
plant.
Reproduction of Seedless Plants: (p.100101) - Continued
• Seedless plants need a moist environment with
lots of water to reproduce.
• Green moss plants are gametophytes.
• Moss sporophytes are the tall, thin stalks that
grow from the gametophytes.
– The spores are produced in capsules on the
sporophytes, and when they’re ready, they
pop open and the wind or water carries the
spores elsewhere so a new plant can begin to
grow.
• With ferns, the same process happens.
Repoduction of Plants with Seeds: (p.102-103)
• Seeds enable plants to grow in many environments.
They don’t need a moist environment with lots of water
for fertilization to happen.
• Seeds of pines are considered to be “naked” because
they are only protected by a seed coat.
– A plant that produces naked seeds is a gymnosperm.
• When the pollen (male part of the plant) joins with the
ovules (female part of the plant) fertilization happens.
– A new life cycle begins as the zygote develops into seeds.
– When the seeds are ready, the cones separate, and the seeds
(which have wings) travel on the wind.
– When a seed lands in a suitable habitat, a tree begins to grow.
Reproduction of Plants with Seeds: (p.102103) - Continued
• Gymnosperm: A plant that produces naked seeds.
Reproduction of Plants with Seeds: (p.102-103) Continued
• Seeds inside fruit are protected (think of an apple). They
are called angiosperms.
– They have flowers, instead of cones.
– The flowers produce seeds inside the fruit.
Flowers to Seeds: (p.104-105)
• The petals of a flower are like advertisements for the
flowers.
– Colors: Lure animals to the flowers, making it more likely that
the animals (like bees for example) will transfer their pollen.
– Scents: Also help to attract animals as well.
• Bees love the sugary nectar found in flowers. When they
crawl in to get the nectar, the pollen sticks to the bee’s
hair legs.
– The pollen comes from the male part of the plant called the
anther.
• When a bee travels to another plant, some of the pollen
that was stuck on the legs of the bee clings to the
stigma.
– The female part of the plant is called the stigma.
• Once fertilization has happened (the pollen from the
anther sticking to the stigma) an embryo begins to
develop.
– The embryo has a root and one or two leaves.
Flowers to Seeds: (p.104-105) - Continued
Seed Germination: (p.106)
• Seeds can germinate, or sprout, when conditions are
right for growth.
• A thick hard seed coat protects the embryo until the seed
is ready to germinate.
• Some seeds germinate when there are enough hours of
light.
• Others germinate when the soil is warm enough.
• A seed absorbs water, which breaks the seed coat. The
embryo begins to grow.
– The root emerges from the seed, anchoring the plant and
absorbing water.
– A shoot pushes up.
– There are no leaves for the plant to make food. They get their
food from cotyledons until the plant can make its own food.
– When the plant develops leaves to make food, the plant begins
to grow much faster.
Seed Germination: (p.106) - Continued