NCERT Solutions for Class 9th Science Chapter 12 Let us explore — Activity 12.6

Look for bryophytes as green mats on damp shaded surfaces — the walls of old buildings, damp rocks, the base of trees, or the soil surface after the monsoon. Lift a small piece with a blunt knife, keeping it damp, and put it in a watch glass.

What the hand lens shows:

• The whole plant is tiny — usually only 1 to 3 cm tall.
• There are thin, hair-like threads at the base that hold it to the surface. These are rhizoids — root-like, but not true roots.
• Above them, in a moss, is a slender stem-like axis with very small leaf-like structures spirally arranged around it. In Marchantia (a liverwort) there is no such axis at all — the body is a flat green ribbon lying on the soil.
• You may see fine stalks rising from the mat with a capsule at the tip — the spore-producing part.

The drop of water does two things: it keeps the specimen alive, and it makes the very thin leaf-like structures transparent so light passes through them.

What you should see under the dissecting microscope:

• The "leaf" is usually one cell thick, so you can see the individual cells and the green chloroplasts inside them without any staining or sectioning.
• There is no midrib and no network of veins.
• The rhizoids are simple threads, not branched absorbing roots.
• The whole plant may spring back and unfold as it takes up water — a dry moss revives in minutes.

A bryophyte "leaf" is not a true leaf at all. It is a flat, usually one-cell-thick green flap with no veins, no midrib, no stalk and no waxy cuticle. An ordinary leaf from a neem or mango tree is many cells thick, has a midrib with a branching network of veins, a petiole, and a waxy cuticle with stomata.