Introduction to Telome Theory: It is now widely accepted (on the basis of overwhelming amount of evidence) that the land- dwelling plants evolved from aquatic ancestors. Ail organisms known in the Precambrian, Cambrian and Ordovician periods of Paleozoic Era lived in aquatic environment. The evolutionary conquest of land probably occurred sometimes between the late Cambrian and early Silurian. The concrete [...]
In this article we will discuss about the vegetative and sexual modes of reproduction in lycopodium with the help of diagrams. Vegetative Reproduction: Vegetative means of propagation is quite common in the sporophyte of Lycopodium which take place by the following methods: (i) By the Formation of Gemmae or Bulbils: These are modified lateral branches which develop on the stem [...]
In this article we will discuss about the structure of Marchantia with the help of diagrams. External Structure of Marchantia: The gametophyte of Marchantia is a dichotomously branched, prostrate, dorsiventral thallus (Fig. 6.8). The dorsal surface of the thallus shows many regular rhomboidal or polygonal areas (Fig. 6.9A). Each area has a pore at the center. A distinct median groove [...]