Gymnosperms and Angiosperms

Two types of seed plants

• Plants that produce seeds are called “seed plants”

• Pine trees and apple trees are both seed plants

Characteristics:1) Many have needle-like or scale-like leaves

2) Deep growing root system

3) Very ancient – been on earth about 360 million years

Gymnosperms!Definition:A seed plant that produces “naked seeds”– They are called “naked” because they are not

enclosed by a protective fruit– No fruit because no flowers!

4 types of gymnosperms survive today

1) Cycads – Grow mainly in tropical and

subtropical areas– Look like palm trees with cones

2) Conifers (means cone-bearing plant)– Largest group of gymnosperms– Most are evergreens

4 types of gymnosperms survive today

3) Ginkgoes – Many species alive millions of

years ago– Only one survives today (Ginkgo

biloba)

4) Gnetophytes– Live in hot deserts and tropical

rain forests– Can be trees, shrubs, or vines

Reproduction in Gymnosperms

**Look at the picture on page 275 in your book**4 Steps:1. Pollination– Transfer of pollen (sperm) from male cone to female cone– Pollen carried by wind

2. Fertilization– Sperm cell fertilizes the egg cell– Fertilized egg develops into embryo part of the seed

3. Seed Development– Seed matures, can take up to 2 years!

4. Seed Dispersal– When seeds are mature the wind carries seeds away.

Angiosperms!

Definition:A seed plant that produces flowers, which turn

into seeds that are enclosed in fruit

The Structure of Flowers

Pistil

A flower is the reproductive structure of an angiosperm

Reproductive Organs:• Pistil

– Female part of the flower– Stigma = sticky tip– Style = connects stigma & ovary– Ovary = contains ovule

• Stamen– Male part of the flower– Anther produces pollen– Filament holds up anther

The Structure of Flowers

Pistil

Petals help with pollination!• Colors and shapes attract pollinators• Pollinators include birds, bats, and insects• Wind can also pollinate flowers

The other parts can play a role in reproduction!

Non-reproductive parts:• Sepals

– Protect the developing flower– Often green in color

• Petals– Shape, size, and number are different

from flower to flower

Reproduction in Angiosperms

**Look at the picture on page 279 in your book**4 Steps:1. Pollination– When a grain of pollen falls onto the sticky stigma

2. Fertilization– Sperm cell fertilizes the egg cell– Egg cell is inside an ovule which is in an ovary

3. Fruit Development– After fertilization, the ovary becomes a fruit

4. Seed Dispersal– Animals eat fruits that contain seeds and disperse the seeds

Types of Angiosperms

Two major groups of angiosperms:

• Monocots– Examples:

grass, corn, lilies, tulips• Dicots

– Examples: roses, maple trees, beans, apples

“Cot” is short for cotyledon– Cotyledon = seed leaf