1) Class Hepatopsida (Liverworts) *Ricciocarpus* and *Riccia*

Question 1

1) List two features of Ricciocarpus and Riccia.

Answer 1

1. Apical growth & dichotomous development.
2. Spongy internal tissue with compact storage tissue.

Question 2

2) Rhizoids?

Answer 2

1. Aquatic plants lack rhizoids.
2. Plants growing on soil have rhizoids on ventral surface.

Question 3

3) Features of male & female gametangia?

Answer 3

1. In Ricciocarpus, male & female gametangia on dorsal surface (dorsal furrow).
2. Male gametangia (antheridia) produce biflagellate sperm.
3. Female gametangia (archegonia) is flask-shaped. At maturity, it contains single egg.

Question 4

4) Structure of archegonia & antheridia (3 points).

Answer 4

1. Both composed of fertile cells surrounded by sterile cells.
2. Antheridia consist of a stalk & sterile jacket which surround spermatogenous tissue.
3. Archegonial neck has six rows of neck cells.

Question 5

5) Type of sexual reproduction?

Answer 5

Oogamous

Question 6

6) Process of reproduction?

Answer 6

1. Zygote develops into mass of diploid tissues (sporophyte) within archegonium.
2. Enlarged archegonium is called calyptra.
3. Sporocytes (diploid cells) divide meiotically twice to give tetrad of **meiospores **(haploid cells).
4. Meiospores develop thick walls, separate, and are shed by decay of the gametophyte. They develop to new plants.
5. Sporophytes of liverworts, hornworts, and mosses are borne within the gametophyte (not free living).