1. Ch.8
Plants

2. Section 4: Gymnosperms and Angiosperms
A gymnosperm is a seed plant that produces naked seeds (not being enclosed by a protective fruit)
Every gymnosperm produces naked seeds. In addition, many gymnosperms have needle-like or scale-like leaves, and deep-growing root systems
Oldest type of seed plant
Four types: cycads, conifers, ginkgoes, and gnetophytes

3. Section 4: Gymnosperms and Angiosperms
Cycads
Grow mainly in tropical and subtropical areas; look like palm trees w/ cones, & grow as big as a football
Conifers
Cone-bearing, & largest/most diverse groups
Ex: pines, sequoias, junipers, are evergreens
Keep there leaves year round
Ginkgoes
Only one species living today & are planted along city streets because they can tolerate air pollution
Gnetophytes
Live in hot desert & tropical rain forest

4. Section 4: Gymnosperms and Angiosperms
Reproduction in Gymnosperms
Most gymnosperms have reproductive structures called cones (are covered with scales)
Form two types of cones: male and female
Single plants produce both male/female but some trees produce either male/female but some produce no cones at all
The female gametophyte develops in structures called ovules (is a structure that contains an egg cell)
First, pollen falls from a male cone onto a female cone. In time, a sperm cells and an egg cell join together in an ovule on the female cone
After fertilization occurs, the seed develops on the scale of the female cone

5. Section 4: Gymnosperms and Angiosperms
Reproduction in Gymnosperms
Pollination
The transfer of pollen from a male reproductive structure to a female reproductive structure is called pollination; wind carries the pollen from male to female; the pollen collects is a sticky substance produced by each ovule
Fertilization
The ovule closes and seals in the pollen; the scale close, and a sperm cell fertilizes an egg cell inside each ovule; then develops into the embryo part of the seed

6. Section 4: Gymnosperms and Angiosperms
Reproduction in Gymnosperms
Seed Development
Female cones remain on the tree while the seeds mature; the seed develops increasing in size which could take up to two years
Males cones fall off the tree after they have shed their pollen
Seed Dispersal
When the seeds are mature, the scales open; the wind shakes the seeds out of the cone and carries them away

7. Section 4: Gymnosperms and Angiosperms
All angiosperms, or flowering plants, share two important traits. First, they produce flowers. Second, in contrast to gymnosperms, which produce uncovered seeds, angiosperms produce seeds that are enclosed in fruits

8. Section 4: Gymnosperms and Angiosperms
The Structure of Flowers
Flowers come in all sorts of shapes, sizes, and colors. But, despite their differences, all flowers have the same function – reproduction
A flower is the reproductive structure of an angiosperm
Sepals and Petals
When a flower is still a bud, it is enclosed by leaflike structures called sepals (protect the developing flower and are often green in color)
When the sepals fold back, they reveal the flower’s colorful, leaflike petals (most colorful part of the flower)

9. Section 4: Gymnosperms and Angiosperms
The Structure of Flowers
Stamens
The stamens are the male reproductive parts
The thin stalk of the stamen is called the filament
Pollen is produced in the anther, at the top of the filament
Pistils
The female parts, or pistils are found in the center of most flowers (some flowers have 2 or more)
The sticky tip of the pistil is called the stigma
A slender tube, called a style, connects the stigma to a hollow structure at the base of the flower
This hollow structure is the ovary, which protects the seeds as they develop

10. Section 4: Gymnosperms and Angiosperms
The Structure of Flowers
Pollinators
To ensure that pollination occurs the colors and shapes of most petals and the scents produced by most flowers attract insects and other animals
Reproduction in Angiosperms
First, pollen falls on a flower’s stigma. In time, the sperm cell and egg cell join together in the flower’s ovule. The zygote develops into the embryo part of the seed

11. Section 4: Gymnosperms and Angiosperms
Reproduction in Angiosperms
Pollination
Pollinated when a grain of pollen falls on the stigma, by the wind, birds, bats, or insects
Nectar, a sugar-rich food, is located deep inside a flower; when an animal enters a flower to get the nectar, it brushes against the anthers and becomes coated with pollen dropping the pollen onto the stigma
Fertilization
Fertilization occurs when pollen falls on the stigma
A sperm cell joins with the egg cell inside the ovule, then the zygote begins to develop into the seed’s embryo

12. Section 4: Gymnosperms and Angiosperms
Reproduction in Angiosperms
Fruit Development and Seed Dispersal
As the seed develops after fertilization, the ovary changes into a fruit – a ripened ovary and other structures that enclose one or more seeds
Fruits are the means by which angiosperm seeds are dispersed
Types of Angiosperms
Angiosperms are divided into two major groups: monocots (are angiosperms that have only one seed leaf) and dicots (produce seeds with two seed leaves)

13. Section 4: Gymnosperms and Angiosperms
Types of Angiosperms
Monocots
Ex: corn, wheat, rice, lilies, and tulips
Have 3 petals or a multiple of three petals
Have long, slender leaves with veins that run parallel to one another
Stems are scattered randomly throughout the stem
Dicots
Ex: roses, violets, dandelions, oak/maple trees, beans, and apples
Four or five petals
Leaves are wide, with veins that branch many times
Stems have bundles of vascular tissue arranged in a ring

14. Section 4: Gymnosperms and Angiosperms
Seed Plants in Everyday Life
Provide useful products such as paper and the lumber used to build homes
Conifers are used to produce turpentine, & rayon
Angiosperms are important source of food, clothing, and medicine
People eat vegetables, fruits, and cereals, which all are angiosperms