14
Gymnosperms and Angiosperms Science class 7 th grade Ms. Artigas

Gymnosperms and Angiosperms

Embed Size (px)

Citation preview

Page 1: Gymnosperms and Angiosperms

Gymnosperms and Angiosperms

Gymnosperms and Angiosperms

Science class 7th gradeMs. Artigas

Science class 7th gradeMs. Artigas

Page 2: Gymnosperms and Angiosperms

• The term "gymnosperm" refers to a group of plants that produce "naked" seeds and pollen. The term "naked" seed refers to a seed that does not develop and mature within a protective layer called the fruit.

Page 3: Gymnosperms and Angiosperms

• Gymnosperms are classified into:

• CycadsAbout 175 million

years ago, the majority of plants were cycads. Today they grow mainly in tropical and subtropical areas. Cycads look like palm trees with cones. A cycad cone can grow as large as a soccer ball.

Page 4: Gymnosperms and Angiosperms

• Gymnosperms are classified into:

• ConifersConifers, or cone-bearing plants, are the largest and most diverse group of gymnosperms today. Most conifers, such as pines, sequoias, and junipers, are evergreens—plants that keep their leaves, or needles, year-round. When needles drop off, they are replaced by new ones.

Page 5: Gymnosperms and Angiosperms

• Conifers include plants that are familiar to most people. These plants have leaves that are needle-like or scale-like and bear reproductive structures called cones .

Page 6: Gymnosperms and Angiosperms

• Gymnosperms are classified into:• GinkgoesGinkgoes (ging kohz) also grew hundreds of millions of years ago, but today, only one species of ginkgo, Ginkgo biloba, exists. It probably survived only because the Chinese and Japanese cared for it in their gardens. Today, ginkgo trees are planted along city streets because they can tolerate air pollution.

Page 7: Gymnosperms and Angiosperms

• Gymnosperms are classified into:• GnetophytesLive in hot deserts and in tropical rain forests. Some are trees, some are shrubs, and others are vines. The Welwitschia grows in the deserts of West Africa and can live for more than 1,000 years.

Page 8: Gymnosperms and Angiosperms

Life Cycle of a

Gymnosperm

Page 9: Gymnosperms and Angiosperms

• Angiosperms• Called 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.

Page 10: Gymnosperms and Angiosperms

• A flower is the reproductive structure of an angiosperm. A flower bud is enclosed by leaf like structures called sepals that protect the developing flower.

• Most flowers have petals—colorful, leaf like structures. Within the petals are the flower’s reproductive parts. Thin stalks topped by small knobs inside the flower are stamens, the male reproductive parts.

• A stamen consists of an anther and a filament Pollen is produced in the anther. The female part, or pistil, consists of a stigma, style, and ovary. An ovary is a flower structure that protects seeds as they develop. An ovary contains one or more ovules.

Page 11: Gymnosperms and Angiosperms
Page 12: Gymnosperms and Angiosperms

Life Cycle of an

Angiosperm

Page 13: Gymnosperms and Angiosperms

• Angiosperms are divided into two major groups: monocots and dicots. Monocots are angiosperms that have only one seed leaf. Dicots produce seeds with two seed leaves.

• Seed plants have many uses. For example, paper, lumber, turpentine, and other products come from gymnosperms. Angiosperms provide food and are used to make clothing, rubber, and furniture.

Page 14: Gymnosperms and Angiosperms