Seedless Vascular Plants

A collection of flashcards based on the lecture notes covering the characteristics, classification, and significance of seedless vascular plants.

What are seedless vascular plants?

Plants that have vascular tissues but do not produce seeds, including ferns, horsetails, and lycophytes.

What are bryophytes?

Nonvascular plants that were the prominent vegetation for the first 100 million years of plant evolution.

What type of tissue allows plants to grow taller?

Vascular tissue.

Where are seedless vascular plants typically found?

Moist habitats, as their sperm require water to swim to the egg.

What defines early vascular plants in terms of size?

They had branching sporophytes that were less than 20 cm tall.

How does the life cycle of vascular plants differ from that of bryophytes?

In vascular plants, the sporophyte is dominant and lives relatively independently of the gametophyte.

What are the two main types of vascular tissue?

Xylem and phloem.

What does xylem transport?

Water and minerals.

How are phloem cells arranged?

In tubes for the transport of organic materials like sugar.

What evolutionary advantages do vascular tissues provide?

They offer structural support and long-distance transport necessary for tall growth.

What are the main organs of vascular plants?

True stems, roots, and leaves.

What is the purpose of leaves in vascular plants?

To increase surface area for capturing light and conducting photosynthesis.

What are sporophylls?

Modified leaves that bear sporangia.

What do homosporous plants produce?

One type of spore that typically generates bisexual gametophytes.

What does heterosporous mean?

Plants that produce two types of spores leading to male and female gametophytes.

Which clades consist of seedless vascular plants?

Phylum Lycophyta and Phylum Monilophyta.

What are some examples of lycophytes?

Club mosses, spike mosses, and quillworts.

What characters classify Monilophytes?

They include ferns, horsetails, and whisk ferns.

What is unique about whisk ferns?

They have dichotomously branching stems but lack true roots.

How are horsetails characterized?

They have jointed stems with rings of small leaves or branches.

What did Carboniferous forests primarily consist of?

Lycophytes, horsetails, and ferns.

What effect did tree roots have during the Carboniferous period?

They broke down rocks and contributed to a drop in atmospheric CO2.

What does a frond refer to in ferns?

A large leaf that is often divided into leaflets, typically coiling at the tip as a fiddlehead.

What do gametophytes of seedless vascular plants primarily develop from?

Spores through the process of gametogenesis.

What is a strobilus?

A cone-like structure composed of clumps of sporophylls.

What did peat ultimately convert into over millions of years?

Coal.

What is the significance of seedless vascular plants in history?

They played a role in Earth's climate by affecting atmospheric CO2 levels.

What is the main characteristic of microphylls?

Small leaves with a single vein found in lycophytes.

What role does lignin play in xylem cells?

It strengthens the cells, making them dead at functional maturity.

What type of spore do megasporangia produce?

Relatively large megaspores that develop into female gametophytes.

How many species of small lycophytes remain today?

About 1,200 species.

What phenomenon resulted from the slow decay of organic material in Carboniferous swamps?

The formation of peat.