Introduction to plants Chapter 12

Warm up How many types of plants do you know? Can you name them.

Objectives Identify four characteristics that all plants share. Distinguish between sporophyte and gametophyte. Define nonvascular plants. Define vascular plants. Recognize mosses an an example of nonvascular plants. Describe the life cycle of a moss. Recognize ferns as seedless vascular plants. Describe the lifecycle of a fern.

Introduction How can you differentiate a plant from an animal?

Characteristics of plants Plants come in different sizes and different shapes. So, what do cactuses, water lilies ferns and all other plants have in common?

1-

2- Cuticle Most plants live on dry land and need sunlight to live. But why don’t plants dry out? A cuticle is a waxy layer that coats most of the surfaces of plants that are exposed to air and keeps plants from drying out.

3- cell wall How do plants stay upright? Carbohydrates and proteins in the cell wall form a hard material. Cell wall support and protect the plant cell.

4- Reproduction Plants have two stages in their lifecycle: 1- the sporophyte stage 2- the gametophyte stage

Sporophyte and gametophyte stages

Sporophyte stage In this stage the plant make spores. In a suitable conditions such as damp soil the spore of some plants grow. These new plants are now called gametophyte.

Gametophyte stage During this stage, female gametophytes produce eggs and male gametophyte produce sperms. Egg and sperm are sex cells. Once they join the fertilized egg grows into a sporophyte that makes spores and the cycle starts again.

Plant classification Although all plants share basic characteristics, they can be classified into four groups. At first plants can be: 1- vascular plants 2- nonvascular plants

Vascular and nonvascular plants

Nonvascular plants Examples: Moses, liverworts and hornworts. They don’t have specialized tissues to move water and nutrients through the plant. Depend on diffusion to move materials from one part to another. They are small in size.

Vascular plants They have vascular tissue: specialized tissue for the transport of water and nutrients. They can be of different sizes and shapes. Live almost everywhere Have true roots, stems and leaves. Are divided into three groups: seedless plants, flowering plants with seeds and nonflowering plants with seeds

Seedless plants Vascular PlantsNonvascular Plants Ferns Mosses, liverworts and hornworts

Types of Mosses

Characteristics of Mosses No true roots, No vascular tissues (no transport) Simple stems & leaves Have rhizoids for anchorage. Live in Damp terrestrial land

Life cycle of mosses

Seedless vascular plants: Ferns roots, feathery leaves & underground stems vascular tissues have vascular tissues (transport & support) Spore-producing organ Spore-producing organ on the underside of leaves (reproduction) Dampshady Damp & shady places Example: ferns, horsetail and club mosse

Wrap up What are the four characteristics between plants? Describe the lifecycle of a plant. Classify the different groups of plants. Differentiate between mosses and ferns. What is the difference between gametophyte of a moss and that of a fern.

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