Seed Plants

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Transcript Seed Plants

Seed Plants
What is a seed plant?
• Seed plants have two important
characteristics:
– Vascular tissue
– Use pollen and seeds to reproduce
What is a seed plant?
• Vascular tissue
– Vascular tissue helps seed plants stand upright
and supply their cells with food and water.
– There are two types of vascular tissue:
• Phloem – where food moves through
• Xylem – where water and minerals move through
What is a seed plant?
• Reproduction
– Seed plants produce pollen, which are tiny
structures that contain cells that will later become
sperm cells.
– Pollen delivers sperm cells directly near the eggs.
– After the sperm fertilizes the egg, a seed develops.
– A seed contains a young plant in a protective
covering.
How seeds develop
• Inside a seed is a partially developed plant.
• If a seed lands in an area where conditions are
favorable, the plant sprouts out of the seed
and begins to grow.
Seed Structure
• A seed has three main parts:
– Embryo
– Stored food
– Seed coat
Seed Structure
• Embryo
– The young plant that develops from the zygote is
the embryo.
– The embryo already has the beginnings of roots,
stems, and leaves.
Seed Structure
• Stored food
– The seed has stored food for the embryo to use in
between the embryo and the seed coat.
Seed Structure
• Seed coat
– The outer covering of a seed is its seed coat.
– The seed coat protects the embryo and the food
from drying out.
Roots
• Roots do three things for a plant:
– Anchor it to the ground
– Absorb water and minerals from the soil
– Sometimes store food
Stems
• The stem has two major functions:
– Carry substances between the plant roots and
leaves.
– Provide support to the plants and hold up the
leaves so they can get the sunlight they need.
Leaves
• Leaves capture the sun’s energy and carry out
the food-making process of photosynthesis.