Q.12. Give comparative account of sporophyte of Marchantia, Pellia and Anthoceros. (2005)
Ans. Comparative account of sporophyte -
Q.13. Write difference between elater and elaterophore. (2006)
Ans. Elaters: -
Elaters are those sterile cells which are found with the spores of sporophyte capsule. It is believed that, the main function, of these elaters is to help in spore dispersal. Elaters are found in Marchantia, Pellia and Anthoceros. Each elater is a diploid cell. In Marchantia spiral thickening bands are present on the elaters. These bands are not found on the elaters of Anthoceros. Elaters of Anthoceros are called pseudo-elaters. Elaters are hygroscopic in nature and help in dispersal of spores.
Elaterophores: -
Elaterophores are found in species of Metzgerineae. On the basis of position, elaterophore is of two types - (i) basal elaterophore, e.g., Pellia (ii) apical elaterophore, e.g., Anura. Some of the sporogenous cells of the base of capsule become sterile during initial stage. These cells grow in length and radiate into the cavity of capsule toward head from base. These are known as elaterophore. The cells of elaterophores consists of spiral thickening bands. Elaterophore are spindle shaped and dark brown in colour, found in groups. Elaterophores help in spore dispersal and dehiscence of capsule.
Q.14. Describe the affinites of Bryophytes withAlgae. (2005, 10)
Ans. Affinites of Bryophytes with Algae
1. The main plant is gametopyte and thalloid in structure.
2. Plants are mostly autotrophic.
3. Chloroplasts usually contain chlorophyll ‘a’, ‘b’, carotenoid and lutein.
4. Starch is the man reserve food material.
5. Vascular system is absent.
6. Pyrenoids are found in Anthoceros and green algae.
7. Root is absent.
8. Cell wall is made of cellulose and pectose.
9. The antherozoids are motile and flagellate.
10. Main phase of life cycle is gametophyte.
11. Water is essential for the act of fertilization.
12. In some bryophyta, protonema is formed which is similar to algal filaments.