Chapter 26: Evolution of Plants

Principles of Biology 2

What is the basic evolutionary sequence emphasized for plants

Retention of the egg in the parental organism → branched apical growth → protected embryo → land plants/embryophytes.

What is an important characteristic of land plants

They retain and protect the developing embryo.

What are embryophytes

Land plants.

What is the major evolutionary advantage of retaining the embryo

The developing embryo is protected and nourished by the parent.

What is apical growth

Growth from the tips of stems and roots.

Why was branched apical growth important

It allowed plants to explore more of their environment and capture resources over a larger area.

What major problem did plants face when moving onto land

They had to survive without constantly being surrounded by water.

What adaptations helped plants live on land

Protection against water loss, protected embryos, specialized reproductive structures, vascular tissue, roots, and supporting tissues.

What are the major nonvascular land plants

Bryophytes, including mosses and their relatives.

What are the major vascular plants without seeds

Lycophytes and monilophytes.

What are monilophytes

A major group of seedless vascular plants that includes ferns and horsetails.

What two groups are included within Monilophyta according to the study guide

Equisetophyta (horsetails) and Polypodiophyta (ferns).

What are seed plants

Plants that reproduce using seeds.

What are the two major groups of seed plants

Gymnosperms and angiosperms.

What are gymnosperms

Seed plants with “naked” seeds that are not enclosed inside fruits.

What are angiosperms

Flowering plants whose seeds are enclosed within fruits.

What advantage does vascular tissue give plants

It allows water, minerals, and sugars to be transported throughout the plant.

What are the two major vascular tissues

Xylem and phloem.

What does xylem transport

Water and minerals.

What does phloem transport

Sugars and other organic materials.

What is alternation of generations

A life cycle that alternates between a haploid gametophyte generation and a diploid sporophyte generation.

What is a gametophyte

The haploid generation that produces gametes.

What is a sporophyte

The diploid generation that produces spores.

What type of cell division produces spores

Meiosis

What type of cell division produces gametes in the gametophyte

Mitosis

Which generation is dominant in bryophytes

The gametophyte.

Which generation is dominant in vascular plants

The sporophyte.

What happens to the gametophyte as plants evolve toward seed plants

It becomes smaller and increasingly dependent on the sporophyte.