Unit 3: Diversity of Life
Module 6: Kingdom Plantae
Learning Objectives: 3.1,3.2
Lesson 1: The vascular plants and the non-vascular plants
Lesson Objectives:
- To compare the vascular and nonvascular plants.
- To study the reproductive cycle of a typical non-vascular plant.
Evaluation:
- Activity: The Bryophytes
- Activity: Division of the Vascular Plants
The terrestrial (land) members of the plant kingdom are generally organized or divided into two broad groups, the vascular plants and the non- vascular plants. The vascular plants have vascular, or conducting, tissue and are grouped together as the tracheophytes. As their name implies, the non-vascular plants, or the bryophytes, do not contain specialized conducting (vascular) tissue. The general features of each of the groups are described below:
A. Non-vascular Plants:
i) Do not have true roots, stems and leaves.
These plants have organs that appear similar to true roots, stems and leaves but they are not true organs. Because of the lack of roots and stems these plants cannot reach water under the soil and actively take it up. They absorb water directly through their cell walls and the water moves from cell to cell via osmosis.
ii) No vascular tissue.
Vascular tissue consists of special cells for the transport of water and nutrients. The root-like, stem-like and leaf-like organs that appear on these plants are not considered true because they do not contain vascular tissue. Lack of vascular tissue limits the size of the plant because it cannot transport water and food very far against gravity.
iii) Small size.
The characteristics described above limit the size of the plant.
iv) Depend on water for reproduction.
This is a limitation because they cannot survive in dry areas. External water is needed for the sperm to swim to the egg.
Examples: Mosses, Liverworts, Hornworts
B. The Vascular Plants:
i) Have structures called true roots, stems and leaves.
ii) Vascular tissue is present.
These special transport cells run continuously through the roots, stems and the leaves.
iii) Larger in size.
iv) Cuticle is present to reduce water evaporation from leaves.
Examples: Ferns, conifers, flowering plants
Activity: The Bryophytes (the non-vascular plants)
Reading: "Nonvascular 'Land' Plants" p. 446-447 Nelson Biology
Some of the main characteristics of the bryophytes are described above in the information on non-vascular plants. The most common bryophytes are the mosses. Recall that mosses require water for reproduction, in order for the sperm to swim to the egg. It is important to understand the main steps involved in reproduction of the mosses. The easiest way to study this is to study the moss life cycle.
In order to understand the life cycle of the mosses, you must first understand the following terms. Using a suitable biology resource define the following terms as related plant (moss) reproduction.
- Haploid
- Diploid
- Meiosis
- Alternation of Generations
- Sporophyte
- Gametophyte
Using any of a number of suitable resources find and study a labeled diagram of the moss life cycle. Once you find a diagram you should produce a copy of it for comparative and study purposes.
Activity: Division of the Vascular Plants
A diagram on p.447 of Nelson Biology illustrates the various classifications of the flowering plants. Using arrows and the main headings illustrate and produce a similar diagram in your notes, leaving room to insert notes and examples under each of the main categories of vascular plants. As you proceed through the reading outlined below add notes on the main characteristics and examples of each of the categories of plants.
Reading: "Vascular Plants" p. 447-454 Nelson Biology
