Question

Как изменились мхи в процессе эволюции

Answer 1

Появление у мхов органов — стебля и листьев, а у папоротников — корня и более развитой проводящей системы.

Answer 2

Evolution of Mosses

Mosses are a group of small, non-vascular plants that belong to the division Bryophyta. They are one of the oldest groups of land plants and have undergone significant changes throughout their evolutionary history.

Evolutionary Adaptations: 1. Colonization of Land: Mosses are believed to have evolved from green algae and were among the first plants to colonize land. This transition from an aquatic to a terrestrial habitat required several adaptations, such as the development of specialized structures to absorb water and nutrients from the environment. 2. Non-Vascular Structure: Unlike vascular plants, mosses lack specialized tissues for transporting water and nutrients. Instead, they rely on diffusion and osmosis to absorb water and nutrients directly through their cell walls. 3. Rhizoids: Mosses have thread-like structures called rhizoids that anchor them to the substrate and absorb water and nutrients from the surrounding environment. These structures are not true roots but serve a similar function. 4. Spore Reproduction: Mosses reproduce through spores rather than seeds. They produce spore capsules that release spores, which can germinate and develop into new moss plants under suitable conditions.

Structural Changes: 1. Gametophyte Dominance: Mosses have a life cycle with alternating generations of gametophytes (haploid) and sporophytes (diploid). In mosses, the gametophyte generation is dominant and larger than the sporophyte generation. The gametophyte produces gametes (eggs and sperm) that fuse to form a zygote, which develops into a sporophyte. 2. Leafy and Thalloid Forms: Mosses exhibit a wide range of structural forms. Some mosses have leafy structures, while others have a thalloid (flat and lobed) form. These structural variations allow mosses to adapt to different environmental conditions. 3. Water Conservation Adaptations: Mosses have developed various adaptations to conserve water, such as the ability to enter a dormant state during dry periods and the production of structures called gemmae cups that contain gemmae, which are small reproductive structures capable of producing new moss plants.

Ecological Significance: 1. Ecosystem Engineers: Mosses play a crucial role in ecosystem functioning. They help retain moisture in the soil, prevent erosion, and provide habitats for a variety of organisms, including insects, spiders, and small vertebrates. 2. Carbon Sequestration: Mosses contribute to carbon sequestration by absorbing carbon dioxide from the atmosphere and storing it in their tissues. This makes them important in mitigating climate change.

In conclusion, mosses have evolved various adaptations to survive and thrive in terrestrial environments. These adaptations include the colonization of land, the development of non-vascular structures, spore reproduction, and structural variations. Mosses play important ecological roles and contribute to carbon sequestration.