Question

Plant ancestors and modern bryophytes are/were limited to living in aquatic habitats. Describe adaptive characters and general trends that evolved over time, allowing plants with these features to live in drier, terrestrial habitats.

Answer 1

Bryophytes are the earliest diverging lineages of the extant land plants. They provide insights into the migration of plants from aquatic environments to land. A number of physical features link bryophytes to both land plants and aquatic plants. Bryophytes and terrestrial plants all have chlorophyll and the chloroplast structures are similar. Bryophytes also produce starch stored in the plastids and contain cellulose in their walls same like terrestrial plants. All these similarities indicate that adaptations in bryophytes have allowed plants to develop on terrestrial environments.

Adaptation feature of terrestrial plants are-

The development of gametangia, that provided protection for gametes, the zygote and the developing sporophyte.

To prevent desiccation of plant tissues, a waxy cuticle that covers the soft tissue of the plant to provide protection.

Development of stomata to facilitate gas exchange and water evaporation between the atmosphere and internal intercellular system.

Development of true vascular tissue, for the transfer of minerals and water across the plant.

Development of specialized cell to provide rigidity against gravity.

Development of jacket cells around the reproductive organs.