GYMNOSPERMS AND ANGIOSPERMS The exciting life of cone-bearing and flowering plants!

GYMNOSPERMS AND ANGIOSPERMS

The exciting life of cone-bearing and flowering plants!

History of Gymnosperms280 millions years ago, Earth’s

climate changed.

Long periods of drought and freezing weather caused spore-producing plants to become extinct, but some adapted

and survived!

THE GYMNOSPERMS!

What are GYMNOSPERMS?

1. Vascular plants that produce seeds on cones

2. Seeds are not protected by fruit

3. Do not produce flowers

NAKED SEEDS!

Gymnosperms produce spores!Male cones

Microspores

Male Gametophyte

Pollen (Sperm)

Female cones

Megaspores

Female Gametophyte

Egg Cell

Sperm and egg eventually meet!

NO water necessary!

Gametophyte Development

Male Gametophyte - develops in pollen grains

Female Gametophyte - develops in ovule

What happens next?

•After fertilization, the zygote develops into an embryo.

•Gymnosperm embryos have many Cotyledons

•Cotyledons are food-storage organs that become the plant’s first leaves

Gymnosperm Advantages!

1. Seeds have embryo w/food supply

2. Seeds are protected from harsh conditions by tough seed coat.

3. Seeds are adapted for dispersal so young plant does not have to compete with parent.

4. Fertilization does not require water

From cereal and fruit to cotton and linen…

ANGIOSPERMS!

-Most well-known plants on Earth-Have seeds, roots, leaves, stems, and

FLOWERS and FRUIT!

Monocot vs DicotMonocot DicotOne seed leaf 2 seed leavesSmaller group Majority rules!

ANGIOSPERM ADAPTATIONS!1) Roots and stems store food

2) Leaves of different shapes and sizes to respond to amount of sunlight and

moisture available.

Life Span of Angiosperms

ANNUAL - live for one year or less

BIENNIAL - live for 2 years

PERENNIAL - live several years, flowering once each year

Fruit Formation• Seed develops & ovary around seed

enlarges

• This becomes the fruit!

• The fruit contains the seeds