Question

Comparative account of the gametophyte of funaria, marchantia and anthroceros.

Answer 1

marchantia:

1. Plant is dorsiventral, prostately, flat thallus with prominent midrib and dichotomous bran­ching, and attached to the substratum, by scales and rhizoids (both smoo­th and pegged).

2. Air-pores present on the dorsal surface, lead into large air chambers containing filamentous chloroplasts.

3. Antheridium deve­lops in groups on the upper surface of the lobes of antheridiophores and remains inside the antheridial chambers and arranged in centrifugal order.

anthroceros:

1. Plant is lobed, dor­siventral green thallus with irregular branch­ing and attached to the substratum by rhizoids only.

2. No air-pores or air chambers present, the cells on the dorsal surface contain large chloroplasts and prominent pyrenoids, on the ventral sur­face slits are present which has been Nostoc.

3. Antheridia develop in clusters (4-6) within, antheridial chambers deeply embedded into the dorsal surface of the thallus.

Answer 2

Viruses are named based on their genetic structure to facilitate the development of diagnostic tests, vaccines and medicines. Virologists and the wider scientific community do this work, so viruses are named by the International Committee on Taxonomy of Viruses (ICTV)