Seed Tracheophytes: Gymnosperms

These flashcards cover key vocabulary terms related to gymnosperms and seed tracheophytes, offering definitions and explanations for essential concepts discussed in the lecture.

Gymnosperms

A group of seed-producing plants that includes cycads, Ginkgo, Gnetophytes, and conifers, characterized by naked seeds.

Angiosperms

Seed plants that produce flowers and fruits, with seeds enclosed within an ovary.

Vascular Plants

Plants that have specialized tissues for conducting water and nutrients, including tracheophytes.

Micropyle

A small opening in the ovule of seed plants, through which the pollen tube can enter to fertilize the egg.

Integument

The protective layer of tissues that surrounds the ovule in seed plants.

Megasporangium

The structure within a seed plant that produces megaspores, which eventually develop into female gametophytes.

Polyembryony

A phenomenon where multiple embryos develop from a single fertilized egg or ovule, common in some gymnosperms.

Secondary Growth

Growth that results in an increase in thickness or girth of the plant, primarily through the activity of the cambium.

Progymnosperms

An extinct group of seed plants that exhibit features of both gymnosperms and ferns, showing a transition in plant evolution.

Cycads

A group of seed plants characterized by a stout trunk and a crown of large, hard leaves; they are ancient and primarily tropical.

Ginkgo biloba

A unique species of tree known for its fan-shaped leaves and resilience; often referred to as the maidenhair tree.

Gnetophytes

A group of plants that includes the genera Gnetum, Welwitschia, and Ephedra; known for their unique reproductive structures.

Coniferophyta

A phylum of plants that produce cones and needle-like leaves; includes pines, spruces, and firs.

Exine

The outer layer of the pollen grain, protecting it during development and transport.

Ovule

The structure in seed plants that develops into a seed after fertilization; contains the female gametophyte.

Archegonium

The female reproductive structure in ferns and gymnosperms that produces the egg cell.

Siphonostele

A type of plant stele characterized by a central pith surrounded by vascular tissue, commonly found in ferns.

Heterospory

The production of two distinct types of spores by seed plants, typically microspores (male) and megaspores (female).