The Characteristics of The Characteristics of Seed PlantsSeed Plants

Chapter 10 Section 3Chapter 10 Section 3

Why do scientists believe in these Why do scientists believe in these supposed relationships?supposed relationships?

   We do see varietal variation, but no We do see varietal variation, but no

transition from one major kind of transition from one major kind of plant into another.plant into another.

Seed PlantsSeed Plants

Seed plants share two important Seed plants share two important characteristics.characteristics.

They have vascular tissue, & they They have vascular tissue, & they use pollen & seeds to reproduce.use pollen & seeds to reproduce.

They all have body plans that include They all have body plans that include leaves, stems, and roots.leaves, stems, and roots.

Water, food and minerals are transported Water, food and minerals are transported

throughout plants in vascular tissuethroughout plants in vascular tissue..

TwoTwo types of Vascular Tissues types of Vascular TissuesXylem & PhloemXylem & Phloem

PhloemPhloem is the vascular tissue through is the vascular tissue through which food moves.which food moves.

When food is made in the plant’s leaves, it When food is made in the plant’s leaves, it enters the enters the phloemphloem & travels to other parts & travels to other parts of the plant.of the plant.

Water & minerals travel in the vascular Water & minerals travel in the vascular tissue called tissue called xylemxylem..

The plant’s roots absorb water & minerals The plant’s roots absorb water & minerals from the soil.from the soil.

These materials enter the root’s These materials enter the root’s xylemxylem & & move upward into the stems & leaves.move upward into the stems & leaves.

PollenPollen Seed plants can live in Seed plants can live in

a variety of a variety of environments.environments.

They produce They produce pollenpollen, , tiny structures that tiny structures that contain the cells that contain the cells that later become sperm later become sperm cells.cells.

PollenPollen delivers sperm delivers sperm cells directly near the cells directly near the eggs, therefore seed eggs, therefore seed plants do not need plants do not need water for fertilization water for fertilization to occur.to occur.

Bee covered in pollen.

SeedsSeeds SeedsSeeds are structures are structures

that contain a young that contain a young plant inside a plant inside a protective covering.protective covering.

Inside a seed is a Inside a seed is a partially developed partially developed plant.plant.

If a seed lands in an If a seed lands in an area where area where conditions are conditions are favorable, it sprouts favorable, it sprouts out of the seed & out of the seed & begins to growbegins to grow..

A seed has three main A seed has three main parts- an embryo, parts- an embryo, stored food, & a seed stored food, & a seed coat.coat.

Seed PlantsSeed Plants

The young plant that develops from the The young plant that develops from the zygotezygote, or fertilized egg, is called the , or fertilized egg, is called the embryo & has the beginnings of roots, embryo & has the beginnings of roots, stems, & leaves.stems, & leaves.

The The embryoembryo also has one or two seed also has one or two seed leaves, or leaves, or cotyledonscotyledons. .

In some seeds, the cotyledons store food.In some seeds, the cotyledons store food. The outer covering of a seed is called a The outer covering of a seed is called a

seed coat.seed coat. A seed may remain inactive for awhile.A seed may remain inactive for awhile.

GerminationGermination

Germination occurs Germination occurs when the embryo when the embryo begins to grow again begins to grow again & pushes out of the & pushes out of the seed.seed.

Environmental Environmental conditions, such as conditions, such as temperature & temperature & moisture, must be just moisture, must be just right in order for a right in order for a seed to germinate.seed to germinate.