How do nonvascular plants differ from seedless vascular plants in terms of structure and life cycle dominance?
Nonvascular plants lack vascular tissue and are gametophyte dominant (haploid stage is prominent), while seedless vascular plants have vascular tissue, can grow taller, and are sporophyte dominant (diploid stage is prominent).
Why was the evolution of seeds and pollen significant for plant reproduction?
Seeds protect the plant embryo and provide a food supply, allowing survival in harsh conditions, while pollen enables fertilization without the need for water, allowing plants to reproduce in a wider range of environments.
How do stomata and guard cells regulate water loss and gas exchange in land plants?
Stomata are pores that open and close to allow gas exchange for photosynthesis; guard cells control the opening and closing of stomata, helping to minimize water loss when conditions are dry.
What is the main structural difference between nonvascular plants and seedless vascular plants?
Nonvascular plants lack vascular tissue and lignin, so they remain small, while seedless vascular plants have vascular tissue and lignin, allowing them to grow taller.
Which stage is dominant in the life cycle of nonvascular plants, and which is dominant in seedless vascular plants?
Nonvascular plants are gametophyte dominant (haploid stage), while seedless vascular plants are sporophyte dominant (diploid stage).
How did the evolution of seeds and pollen benefit land plants?
Seeds protect the plant embryo and provide a food supply, while pollen allows fertilization without water, enabling reproduction in a wider range of environments.
What is the function of stomata and how do guard cells control their activity?
Stomata are pores that allow gas exchange for photosynthesis; guard cells open and close the stomata to regulate water loss and gas exchange.
What are the two main types of vascular tissue in plants and what does each transport?
Xylem transports water and minerals, while phloem transports sugars and nutrients throughout the plant.
Why do nonvascular and seedless vascular plants require water for fertilization?
Their sperm must swim through water to reach the egg, so fertilization can only occur when moisture is present.
What adaptation in angiosperms contributed to their great diversity and success?
The evolution of flowers, which are specialized reproductive structures, contributed to the adaptive radiation and diversity of angiosperms.