write the characteristics of division pteriodophyta
Answers
Answer:
1. Pteridophytes are considered as the first plants to be evolved on land:
It is speculated that life began in the oceans, and through millions of years of evolution, life slowly adapted on to dry land. And among the first of the plants to truly live on land were the Pteridophytes.
2. They are cryptogams, seedless and vascular:
Pteridophytes are seedless, and they reproduce through spores. They contain vascular tissues but lack xylem vessels and phloem companion cells.
3. The plant body has true roots, stem and leaves:
They have well-differentiated plant body into root, stem and leaves.
4. Spores develop in sporangia:
The sporangium is the structures in which spores are formed. They are usually homosporous (meaning: one type of spore is produced) and are also heterosporous, (meaning: two kinds of spores are produced.)
5. Sporangia are produced in groups on sporophylls:
Leaves that bear the sporangia are termed as sporophylls. The tip of the leaves tends to curl inwards to protect the vulnerable growing parts.
6. They show true alternation of generations:
The sporophyte generation and the gametophyte generation are observed in Pteridophytes. The diploid sporophyte is the main plant body.
Answer:
1) They mainly thrive in moist and shady places. Some also grow in sandy soils.
2)The main plant body has well differentiated root, stem and leaves. It is called a sporophyte.
3)The stem is underground rhizome.
4)Some pteridophytes have small leaves called microphylls (e.g lycopodium) and some have large leaves called megaphylls (e.g Pteris).
5)Leaves may also have spores on the underside. Such leaves are called sporophylls.
6)Plants are flowerless and seedless. They reproduce by means of spores.
7)Sometimes the sporophylls form compact structures known as cones or strobili.
8)A well-developed vascular system with xylem (for conduction of water) and phloem (for conduction of food) is present.
Explanation: