AP BIOLOGY

Detailed explanation-1: -The earliest plants are thought to have evolved in the ocean from a green alga ancestor. Plants were among the earliest organisms to leave the water and colonize land. The evolution of vascular tissues allowed plants to grow larger and thrive on land.

Detailed explanation-2: -The earliest plants were algae living in the oceans more than 700 million years ago. Modern-day plants evolved from these aquatic algae that did not have stems or roots.

Detailed explanation-3: -The earliest photosynthetic organisms on land would have resembled modern algae, cyanobacteria, and lichens, followed by bryophytes (liverworts & mosses, which evolved from the charophyte group of green algae). Bryophytes are described as seedless, nonvascular plants.

Detailed explanation-4: -An international study has found a drought alarm system that first appeared in freshwater algae may have enabled plants to move from water to land more than 450 million years ago – a big evolutionary step that led to the emergence of land animals, including humans.

Detailed explanation-5: -New data and analysis show that plant life began colonising land 500 million years ago, during the Cambrian Period, around the same time as the emergence of the first land animals.