Plant evolution

Unit 2 biology 112

Adaptations of plants to terrestrial environments

Plants developed adaptations for differentiating tissues, dealing with stresses of land, and exploiting the dual air/water nature of terrestrial environments.

Traits shared with algal ancestors

chloroplasts with photosynthetic pigments, cell walls containg glucose, and starch food reserve.

Chloroplasts

Organelles in plant cells that contain photosynthetic pigments, enabling photosynthesis.

Apical meristems

Regions of undifferentiated cells in plants that are capable of growth and differentiation.

Gametophyte generation

The haploid stage in the life cycle of plants which produces gametes.

Sporophyte generation

The diploid stage in the plant life cycle that produces spores.

Spores

Single haploid reproductive cells that can develop into an adult multicellular organism on their own.

Bryophytes

Non-vascular plants like mosses, liverworts, and hornworts that have a dominant gametophyte generation.

Why are brophytes still tied to water?

becuase there is no waxy cuticle, no stomata, no true leaves and roots, and no stems and vascular tissue

Sori

Clusters of sporangia found on the underside of fern leaves.

Adaptation of ferns to land

Ferns have developed a cuticle, stomata, true leaves, and roots to thrive in terrestrial environments.

Gymnosperms

Seed-producing vascular plants that bear cones and have a dominant sporophyte generation.

Pollen

The male gametophyte in gymnosperms that allows for reproduction.

Seeds in gymnosperms

Protect embryos from desiccation and provide modes of dispersal.

Angiosperms

Flowering plants that have adapted to terrestrial environments with features like fruit and flowers.

Endozoochory

Seed dispersal method where animals eat fruits and excrete seeds elsewhere.

Hydrochory

Seed dispersal method common in plants growing near water, utilizing buoyancy.

Anemochory

Seed dispersal by wind, involving lightweight and small seeds.

Cuticle

A waxy outer layer on leaves that prevents water loss.

Stomata

Pores on the leaf surface that facilitate gas exchange.