Quick algae review

• Habitat• Structure• Type of cell• Transport• Reproduction

MOSSES and FERNSSeedless Plants - Chapter 21

According to The Theory of Evolution:

Life (algae) began in the sea, and for millions of years living things remained in the sea. Yet, slowly, life emerged onto land.

The first land plants have to meet the challenges of living on dry land. Let’s take a look at how they did it.

Progression

Algae(aquatic plants)

Algae-like Land plants

450-500mya

Bryophyte-mosses

-liverworts-hornworts

Tracheophyte-ferns

-higher plantsThese organismshave to face up to the challengesof living on dry land.

What are some challenges tolife on land?

• Drying out• Food

• Diffusion of O2 and CO2• Successful reproduction

Adapting to Life on Land

1. have a constant supply of water to cells

2. be exposed to make food and thus need rigid support to hold up their leaves.

3. be able to transport nutrients & water throughout the plant

- vascular tissue + rhizoids water food

4. Must be able to exchange O2 & CO2 w/o losing too much H2O

5. Be able to reproduce without water- small spores, flagellated sperms

Mature moss capsule Moss capsules

Phylum Bryophyta:Moss, Liverworts, Hornworts

Bryum argenteum Polytrichum juniperinum

Papillaria crocea Leptostomum inclinans

Chinese Club Moss

• Stop here• Homework read p. 449-451• Questions 1-3

How Do Bryophytes Get Water?

Problem: Non-vascular plant1. Via osmosis and capillary action2. Leaves have only one or two cells3. Only about 2 to 5 cm tall, cling to damp

soil, sheltered rocks, and the shady side of trees

4. Rhizoids: root-like structures; mostly for anchor

Critical Thinking

• Your friend finds a small plant growing in the desert. He identifies the plant as a moss. Explain why this plant is probably not a moss.

• Don’t think out loud please.

Structure of Moss

• Please find an empty spot on your handout. =)

Life Cycle of Mosses

• Alternation of generations: process of switching from asexual (haploid) to sexual reproduction (diploid)

Alternation of Generation in Mosses

• Germinate – develop into a plant• Protonema – transitory stage of moss plant• Archegonium

– female organ – egg develops here- Protects gametes

• Antheridium- male organ- sperm develops here

• Protects gametes

Refer to handout on moss reproduction

Your task for the rest of the class.

• Create a placemat and make sure you cover these topics:– Phylum– Adaptation to life on land (5 points)– Where they are found– Type of reproduction– Appearance (description + diagram)– Diagram– Physical features (6 points)Out of 22marks