SS1: BIOLOGY - 1ST TERM
Introduction to Biology | Week 16 Topics|1 Quiz
Recognizing Living Things | Week 23 Topics|1 Quiz
Organisation of Life | Week 33 Topics
Classification of Living Organisms | Week 47 Topics|1 Quiz
Kingdom Prokaryotae / Monera & Kingdom Protista | Week 53 Topics|3 Quizzes
Kingdom Fungi & Kingdom Plantae | Week 69 Topics|2 Quizzes
Kingdom Animalia I | Week 76 Topics|1 Quiz
Kingdom Animalia II | Week 85 Topics|1 Quiz
The Cell | Week 93 Topics|1 Quiz
The Cell Structure and Functions | Week 104 Topics|1 Quiz
The Cell and its Environment | Week 114 Topics|1 Quiz
Nutrition in Plants | Week 124 Topics|1 Quiz
Do you like this content?
Pteridophytes, commonly called ferns or fern allies, are vascular plants and have leaves (known as fronds), roots and sometimes true stems.
Pteridophytes are classified into ferns and club mosses.
Habitat: Damp terrestrial habitats.
Characteristics of Pteridophyta:
1. They have a vascular system for the conduction of water and other substances.
2. They do not bear seeds instead they bear spores.
3. The stem of a fern is a rhizome with long leaves.
4. Fern shows alternation of generation (gametophyte and sporophyte). The mature leaves or fronds of the fern plant (sporophyte stage) bear spores on their underside. The spores mature into young gametophytes which bear the sex organs that contain the eggs and a new sporophyte or document fern plant is produced. Both the sporophyte and gametophyte lead separate existences unlike in the Bryophyte.
5. The sporophyte is dominant in the life cycle of ferns.
6. It possesses large leaves called fronds, true stems & roots.
7. Each gametophyte is called prothallus (which is green and photosynthetic.)
Classification of Pteridophytes:
There are four classes, namely:
Class Lycopsida (Club Mosses)
Habitat: Lycophytes (club mosses) are found almost everywhere on Earth, excluding Antarctica. They grow from the tropics to the Arctic in a range of ecosystems including rainforests, deserts, lakes and wetlands. A large proportion of lycophytes grow from the stems of trees and other plants.
1. These are the first plants to develop a vascular system.
2. They bear leaves called microphyIIs.
3. They possess special cone-like strobilus made up of special leaves called sporophylls arranged closely together. (A sporophyll is a leaf that produces spores.)
4. The sporophyIIs bear sporangia.
5. The sporophytes grow on independent gametophytes.
Difference between Bryophyta & Pleridophyta:
|Vascular tissue |
|Body is differentiated into |
tissue organs and systems.
i.e. Vascular tissue is present.
|They are non-vascular |
|They are vascular plants.|
|No true roots, leaves |
|Have roots, |
stems and leaves.
The sporophyte is dependent
on gametophyte on the
alternation of generation.
|The two generations are |
independent of each other.
|The sporophyte generation |
is more dominant.
|Examples||Mosses, liverworts, |
Alternation of Generation:
In alternation of generation, the sporophyte is always attached to the gametophyte in bryophytes but on pteridophytes, they lead separate lives. The gametophyte produces motile (moving) male gametes and non-motile (non-moving) female gametes. Water is essential for fertilization. The fertilized egg or zygote grows on the gametophyte (Bryophyte) into a sporophyte which produces spores. These spores are dispersed by wind and when they fall in a suitable moist environment, they develop into gametophytes.