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What are the main functions of a plant’s roots, stems and leaves?

Plants

Gymnosperms and Angiosperms

Plants

Gymnosperms and Angiosperms

Chapter 8Section 4

Chapter 8Section 4

Discover Activity

• Are all leaves alike? Page

Objectives:• To identify the characteristics of

gymnosperms and describe how they reproduce.

• To describe the characteristics of angiosperms and their flowers.

• To explain how angiosperms reproduce.• To describe the two types of

angiosperms.• To list products from seed plants.

Gymnosperms

• Gymnosperms are plants that produce naked seeds. Their seed are not enclosed by a protective fruit. Reproductive structures are cones.

Gymnosperms

• Gymnosperms are plants that do not have an ovary. Reproductive structures are cones.

• Gymnosperms consists of four phyla which are cycads, ginkgoes, conifers and gnetophytes.

Gymnosperms

• Cycads are topical plants that look like palm trees.

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_6.html

Cycas revoluta from Hawaii, showing female cones bearing large, orange seeds. Image from http://www.botany.hawaii.edu/faculty/carr/images/cyc_rev_f.jpg.

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_6.html

Cycas revoluta from Hawaii, showing the male cone bearing numerous pollen-producing sporangia. Image from http://www.botany.hawaii.edu/faculty/carr/images/cyc_rev_m.jpg.

Gymnosperms

• Conifers are the largest group of gymnosperms. Most of them are evergreens.

http://www.perspective.com/nature/plantae/conifers.html

http://www.cssd11.k12.co.us/dohnts/Biology/bio06nt.htm#Mosses

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_6.html

Image of Araucaria sp. Note the large female comes at the tips of branches. Image from http://www.botany.hawaii.edu/faculty/carr/images/araucar_sp3.jpg.

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_6.html

Closeup of Sequoia sempervirens leaf and cone. Image from http://www.botany.hawaii.edu/faculty/carr/images/seq_sem_cu.jpg.

Gymnosperms

• Ginkgoes are also called the maidenhair tree and do not exist in the wild.

http://ibiblio.org/herbmed/pictures/p06/pages/ginkgo-biloba-6.htm

http://ibiblio.org/herbmed/pictures/p06/pages/ginkgo-biloba-9.htm

Gymnosperms

• Gnetophytes are a diverse group that share characteristics with both gymnosperms and angiosperms, they tropical vines and desert plants.

Scientific Name Ephedra Copyright © 1996 Michael Donoghue

http://tolweb.org/tree?group=Gnetales&contgroup=Spermatopsida#titlefigcaption

http://tolweb.org/tree?group=Gnetales&contgroup=Spermatopsida#titlefigcaption

Scientific Name Welwitschia

Specimen Condition Live Specimen

Copyright © 1996 Michael Donoghue

http://tolweb.org/tree?group=Gnetales&contgroup=Spermatopsida#titlefigcaption

Scientific Name Gnetum Specimen Condition Live Specimen

Copyright © 1996 Michael Donoghue

Reproduction in Gymnosperms

• Pollination is the process in which pollen is carried from male to female reproductive parts.

• In fertilization, the sperm cell joins with the egg cell.

• Seeds develop and the female cone increases in size.

• When the seeds are mature, the scales open and the wind scatters the seeds.

Try This Activity

• The Scoop on Cones page 274

Angiosperms

• Angiosperms are plants that develop seeds within a structure called the ovary. Reproductive structures are flowers.

• Angiosperms make up the largest group of plants in the world--the flowering plants.

Flowers

• Flowers are the structures that contain the reproductive organs of angiosperms.

http://www.geocities.com/RainForest/6243/diversity4.html#Plant

http://www.perspective.com/nature/plantae/dicots.html

Flower Structure

• Sepals are the leaf-like structures that enclose the bud.

• Petals are the colorful, leaf-like and fragrant structures that attract insects and other animals.

Flower Structure

• Stamen is the male reproductive organ that consist of the filament which is a thin stalk topped by a knoblike part called the anther.

Flower Structure

• Pistil is the female reproductive organ and is located in the center of the flower. The pistil consists of a sticky tip called the stigma at the end of a slender tube called the style.

Flower Structure• Ovary is a hollow structure at the base of

the flower that contains the ovule or ovules.

• A flower is pollinated when a grain of pollen lands on the pistil. The sperm cell will join the egg cell.

• After the egg cell is fertilized, the ovule develops into a seed and the ovary becomes a fruit that encloses and protects the seeds.

A COMPLETE ANGIOSPERM FLOWER

                                                                                                                                                                                     

                                                                                                                                                                    

http://www.csdl.tamu.edu/FLORA/301Manhart/repro/Flower%20diagram/flower_diagram.htm

Activity

• Have students feel the shape, weight, and texture of several fruits. Ask students to describe how the physical characteristics of each fruit and its seeds might be related to the way in which its seeds are dispersed.

Angiosperms

• Angiosperms are divided into two major groups: monocots and dicots.

• “Cot” is short for cotyledon or seed leaf.

• Monocots are angiosperms that have only one seed leaf. Mono meaning one.

• Dicots produce seeds with two seed leaves. Di meaning two.

Monocots• Examples: grasses, corn, wheat,

rice lilies, tulips• Leaves have parallel veins• Stems have randomly scattered

bundles of vascular tissue.• Flowers have petals in multiples of

three.

Dicots• Examples: roses, violets,

dandelions, oak, maple, beans, apples

• Leaves have branching veins.• Vascular tissue is arranged in a

ring.• Flowers have petals in multiples of

four or five.

Math Skills

• Multiples page 280

Actitivities• Teacher Demo• Try This Activity• Teacher Demo

Lab

• A Close Look at Flowers

Homework