Gymnosperms Flashcards
(27 cards)
What are Gymnosperms?
Vascular plants that have naked seeds not enclosed in ovaries and are borne in cones.
What are Angiosperms?
Seed plants that produce flowers and fruits, with fruits being mature ovaries.
What are key adaptations for life on land in seed plants?
Seed and pollen grains.
What does a seed consist of?
An embryo, its food supply, and a protective coat.
What are common characteristics of all seed plants?
- Reduced gametophytes
- Heterospory
- Ovules
- Pollen
What is heterospory?
The production of two different types of spores by seed plants.
What do megasporangia produce?
Megaspores that give rise to female gametophytes.
What do microsporangia produce?
Microspores that give rise to male gametophytes.
What is the integument in seed plants?
A layer of sporophyte tissue that envelops and protects the megasporangium.
What is an ovule?
The whole structure of megasporangium and megaspore, where a female gametophyte develops.
What does pollen consist of?
A male gametophyte enclosed in a pollen wall.
What is pollination?
The transfer of pollen to the part of a seed plant containing ovules.
What was the main protective stage in plant life cycles before seeds?
Spores.
What are the general features of Gymnosperms?
- Woody
- Evergreen (except Larix and Taxodium)
- Perennial
- Grow as trees or shrubs
Where are living gymnosperms primarily found?
Colder regions of Earth.
What are xerophytes?
Species of plants adapted to survive in environments with little liquid water.
What are some adaptations of xerophytes?
- Thick bark
- Thick hypodermis
- Thick cuticle
- Sunken stomata
- Modified leaves
What are strobili?
Large, prominent cones that bear sporangia.
What is the ecological importance of gymnosperms?
- Provide food and habitat for wildlife
- Prevent soil erosion
- Reduce greenhouse-effect gases
What economic uses do gymnosperms have?
- Lumber for wood and paper
- Resins for furniture
- Ornamental plants
- Food sources like pine nuts
What are the four divisions of Gymnosperms?
- Cycadophyta
- Coniferophyta
- Gnetophyta
- Ginkgophyta
What characterizes Division Cycadophyta?
Palm-like plants with thick leaves that resemble tough fern fronds.
What are coralloid roots?
Roots found in cycads that form club-shaped structures containing nitrogen-fixing cyanobacteria.
What type of reproductive structures do cycads have?
Unisexual or dioecious structures bearing either ovules or pollen sacs.
