Question

1. A) When moss spores land on the ground, they germinate to form what structure? This structure resembles the filamentous body of certain green algae. What is the evolutionary significance of this?

B) Explain the process of spore dispersal that takes place in the moss. What environmental factor stimulates the release of the spores? Describe the peristome and explain its role in spore dispersal.

Answer 1

A.) A moss is a flowerless, spore-producing plant with the spores produced in small capsules.The spore capsule, often with a supporting stalk (called a seta), is the sporophyte and this grows from the gametophyte stage. Moss gametophyte consists of leaves on stems.

Some organisms with the name "moss," such as Irish moss, are in fact types of algae. However, true moss and algae are two distinct species with different characteristics. Mosses include 12,000 separate species, while algae are a group of organisms.

Moss mark the transition to land and the origin of vascular plants, and hence, link the seed and vascular plants to their algal ancestors.

B.) Sporophyte generation is short-lived. It comprises a capsule which produces spores by meiosis and a stalk which holds this aloft the gametophyte.

The environmental factor are dispersed temperature, humidity and light, as well as wind or nin, can play a key role in the removal of spores. Wind speed and turbulence or rainfall, largely determine spore dispersal and the major factor responsible is through air currents and, once they settle somewhere moist, germinate.