Exam 27: Plants Without Seeds: From Water to Land

You find a mat of short green plants growing on your neighbor's front lawn.You look at them through a microscope and see that they lack vascular tissue and are dispersing lots of spores from small brown stalks.The plants are most likely a colony of

Describe a likely scenario for how megaphylls developed from overtopping.

Fossilized remains of a rhyniophyte show that these extinct plants lacked

As land plants evolved, the sporophyte generation became larger and less dependent on the gametophyte generation.Which statement provides an accurate example of this trend?

How did the emergence of plants on land change the Earth?

Refer to the figure, which shows alternation of generations in the life cycle of a land plant. In the life cycle of a plant, the spores are _______, the gametes are _______, and the zygote is _______.

If lignin-containing cell walls had not evolved in land plants, we might now have

The addition of tracheid cells strengthened with lignin allowed early land plants to do all of the following except

Refer to the figure, which shows hornworts. In which order did this hornwort plant develop, from oldest to newest growth?

Mosses are dependent on external water for sexual reproduction because

The vascular system in land plants consists of specialized tissues.The _______ transports water and minerals from soil to aerial parts and contains the structural substance called _______.

The branched filamentous structure of the moss gametophyte that develops after spore germination is the

Match the description below with the correct group of seedless vascular plants from the list that follows. This ancient group lacked roots and leaves but had a central column of xylem running through its stems.It had dichotomously branching aerial stems that were occasionally topped by sporangia.

Protection of the embryo by parental tissue was a defining step in the evolution of

In nonvascular plants, the _______ is usually nonphotosynthetic and is _______ dependent on the _______.

Horsetails share with club mosses all of the following characteristics except

Why do ferns often grow in moist habitats?

Refer to the figure, which shows a nonvascular plant. The underside of the starlike structure of the plant body is the location of the _______ generation.

A strobilus is

The evolution of heterospory occurred independently several times in the course of vascular plant evolution.Which statement best explains the possible selective advantages of heterospory in land plants?