Question

Explain how land plants adapted on terrestrial environment: mention general adaptation characteristics, as well as reproductive ones.

Answer 1

As organisms adapted to life on land, they had to contend with several challenges in the terrestrial environment. The cell ‘s interior is mostly water: in this medium, small molecules dissolve and diffuse and the majority of the chemical reactions of metabolism take place. Desiccation, or drying out, is a constant danger for organisms exposed to air.

Even when parts of a plant are close to a source of water, the aerial structures are prone to desiccation. Water also provides buoyancy to organisms. On land, plants need to develop structural support in a medium that does not give the same lift as water.

While some plants remain dependent on a moist and humid environment, many have adapted to a more arid climate by developing tolerance or resistance to drought conditions.

Alternation of generations describes a life cycle in which an organism has both haploid (1n) and diploid (2n) multicellular stages, although in different species the haploid or diploid stage can be dominant.
The life on land presents significant challenges for plants, including the potential for desiccation, mutagenic radiation from the sun, and a lack of buoyancy from the water.

• desiccation tolerance: the ability of an organism to withstand or endure extreme dryness, or drought-like condition
• alternation of generation: the life cycle of plants with a multicellular sporophyte, which is diploid, that alternates with a multicellular