Lesson Overview

Seed Plants

Lesson Overview
22.3 Seed Plants
Lesson Overview

Seed Plants

THINK ABOUT IT
Seeds are so common that they are easy to overlook. What are seeds?
Every see...
Lesson Overview

Seed Plants

The Importance of Seeds
What adaptations allow seed plants to reproduce without open water?
Lesson Overview

Seed Plants

The Importance of Seeds
What adaptations allow seed plants to reproduce without open water?
...
Lesson Overview

Seed Plants

The Importance of Seeds
A seed is a plant embryo and a food supply, encased in a protective ...
Lesson Overview

Seed Plants

The First Seed Plants
Today’s seed plants are all descended from common ancestors.
The fossi...
Lesson Overview

Seed Plants

Cones and Flowers
In seed plants, the male gametophytes and the female gametophytes grow and...
Lesson Overview

Seed Plants

Pollen
In seed plants, the entire male gametophyte is contained in a tiny structure called
a...
Lesson Overview

Seed Plants

Seeds
After fertilization, the zygote contained within a seed grows into a tiny plant
—the s...
Lesson Overview

Seed Plants

The Life Cycle of a Gymnosperm
How does fertilization take place in gymnosperms in the absen...
Lesson Overview

Seed Plants

The Life Cycle of a Gymnosperm
How does fertilization take place in gymnosperms in the absen...
Lesson Overview

Seed Plants

The Life Cycle of a Gymnosperm
The word gymnosperm means “naked seed.” Gymnosperms produce s...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
Reproduction in conifers takes place in cones, which are produce...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
Pollen cones produce pollen grains, which make up the entire mal...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
One of the haploid nuclei in the pollen grain will divide later ...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
Seed cones produce female gametophytes and are generally much la...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
 
Near the base of each scale are two ovules, where the female g...
Lesson Overview

Seed Plants

Pollen Seeds and Seed Cones
Within the ovules, meiosis occurs producing haploid cells that g...
Lesson Overview

Seed Plants

Pollination and Fertilization
In the spring, pollen cones release pollen grains that are car...
Lesson Overview

Seed Plants

Development Inside Seeds
If a pollen grain lands near an ovule, the grain splits open and be...
Lesson Overview

Seed Plants

Development Inside Seeds
Fertilization produces a diploid zygote, which grows into an embryo...
Lesson Overview

Seed Plants

Development Inside Seeds
A seed is an encased embryo that is ready to be scattered by the wi...
Upcoming SlideShare
Loading in …5
×

B10vrv6223

219 views
130 views

Published on

Used with permission from Pearson for Clay Virtual Academy. Copyright Pearson.

Published in: Education, Business, Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
219
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

B10vrv6223

  1. 1. Lesson Overview Seed Plants Lesson Overview 22.3 Seed Plants
  2. 2. Lesson Overview Seed Plants THINK ABOUT IT Seeds are so common that they are easy to overlook. What are seeds? Every seed contains a living plant ready to sprout as soon as it encounters the proper conditions for growth. The production of seeds has been one key to the ability of plants to colonize even the driest environments on land.
  3. 3. Lesson Overview Seed Plants The Importance of Seeds What adaptations allow seed plants to reproduce without open water?
  4. 4. Lesson Overview Seed Plants The Importance of Seeds What adaptations allow seed plants to reproduce without open water? Adaptations that allow seed plants to reproduce without open water include a reproductive process that takes place in cones or flowers, the transfer of sperm by pollination, and the protection of embryos in seeds.
  5. 5. Lesson Overview Seed Plants The Importance of Seeds A seed is a plant embryo and a food supply, encased in a protective covering. The living plant within a seed is diploid and represents the early developmental stage of the sporophyte phase of the plant life cycle.
  6. 6. Lesson Overview Seed Plants The First Seed Plants Today’s seed plants are all descended from common ancestors. The fossil record indicates that ancestors of seed plants evolved new adaptations that enabled them to survive on dry land.
  7. 7. Lesson Overview Seed Plants Cones and Flowers In seed plants, the male gametophytes and the female gametophytes grow and mature directly within the sporophyte. The gametophytes usually develop in reproductive structures known as cones or flowers. Nearly all gymnosperms bear their seeds directly on the scales of cones. Flowering plants, or angiosperms, bear their seeds in flowers inside a layer of tissue that protects the seed.
  8. 8. Lesson Overview Seed Plants Pollen In seed plants, the entire male gametophyte is contained in a tiny structure called a pollen grain. Pollen grains are carried to the female reproductive structure by wind or animals such as insects. The transfer of pollen from the male reproductive structure to the female reproductive structure is called pollination.
  9. 9. Lesson Overview Seed Plants Seeds After fertilization, the zygote contained within a seed grows into a tiny plant —the sporophyte embryo. A tough seed coat surrounds and protects the embryo and keeps the contents of the seed from drying out. The embryo begins to grow when conditions are right. It does this by using nutrients from the stored food supply until it can carry out photosynthesis on its own.
  10. 10. Lesson Overview Seed Plants The Life Cycle of a Gymnosperm How does fertilization take place in gymnosperms in the absence of water?
  11. 11. Lesson Overview Seed Plants The Life Cycle of a Gymnosperm How does fertilization take place in gymnosperms in the absence of water? In gymnosperms, the direct transfer of pollen to the female cone allows fertilization to take place without the need for open water.
  12. 12. Lesson Overview Seed Plants The Life Cycle of a Gymnosperm The word gymnosperm means “naked seed.” Gymnosperms produce seeds that are exposed on the scales within cones.
  13. 13. Lesson Overview Seed Plants Pollen Seeds and Seed Cones Reproduction in conifers takes place in cones, which are produced by the mature sporophyte plant.
  14. 14. Lesson Overview Seed Plants Pollen Seeds and Seed Cones Pollen cones produce pollen grains, which make up the entire male gametophyte stage.
  15. 15. Lesson Overview Seed Plants Pollen Seeds and Seed Cones One of the haploid nuclei in the pollen grain will divide later to produce two sperm nuclei.
  16. 16. Lesson Overview Seed Plants Pollen Seeds and Seed Cones Seed cones produce female gametophytes and are generally much larger than pollen cones.
  17. 17. Lesson Overview Seed Plants Pollen Seeds and Seed Cones   Near the base of each scale are two ovules, where the female gametophytes develop.
  18. 18. Lesson Overview Seed Plants Pollen Seeds and Seed Cones Within the ovules, meiosis occurs producing haploid cells that grow and divide into female gametophytes. Each gametophyte contains a few large egg cells.
  19. 19. Lesson Overview Seed Plants Pollination and Fertilization In the spring, pollen cones release pollen grains that are carried away by the wind, as shown in the figure. Some pollen grains are caught in a sticky secretion on the scales of female cones and are pulled inside towards the ovule. This direct transfer of pollen to the female cone allows fertilization to take place without the need for open water.
  20. 20. Lesson Overview Seed Plants Development Inside Seeds If a pollen grain lands near an ovule, the grain splits open and begins to grow a structure called a pollen tube, which contains two haploid sperm nuclei. Once the pollen tube reaches the female gametophyte, one sperm nucleus disintegrates; the other fertilizes the egg.
  21. 21. Lesson Overview Seed Plants Development Inside Seeds Fertilization produces a diploid zygote, which grows into an embryo.
  22. 22. Lesson Overview Seed Plants Development Inside Seeds A seed is an encased embryo that is ready to be scattered by the wind and grow into a plant.

×