Botany Final GYMNOSPERMS

Unique Characteristics

• Produce seeds and pollen

• Strictly heterosporous

Advanced Adaptations

• developed xylem/phloem for dedicated water/sugar transport

• secondary growth (woody growth)

• ovule/seed

What is a seed?

mature fertilized ovule containing an embryo and protected by a seed coat

• provides protection, food source, dispersal

What is an ovule?

contains the megasporangium and develops into a seed following fertilization

What is a pollen grain?

develops into the microgametophyte and the gamete

• transports sperm to egg, replaces the antheridia

What does the division Coniferophyta entail?

• Conifers

• Needles or scale leaves

• Resin ducts

• Slow growing, secondary growth, monoecious

• Heterosporous

What does the division Cycadophyta entail?

• Cycads

• Produces strobili

• Slow growing, dioecious, large pinnate leaves

• Zamia

What does the division Ginkophyta entail?

• Ginkgo

• Doesn’t produce cones

• Dioecious, fan-shaped leaves

What does the division Gnetophyta entail?

• Ephedra

• Dioecious, bract strobili, double fertilization

Which is the dominant generation?

Sporophyte

Is the antheridium still produced?

No - has been condensed into pollen grains

What is the integument?

Surrounds the megasporangium in the ovule

What is pollination?

transportation of pollen. facilitates fertilization

What is polyembryony?

2+ embryos develop from a single fertilized egg

What are pollen grains?

Multicelled structures that can travel much further than spores or sperm can

What are the components of an ovule?

• Megagametophyte

• Archegonium

• Egg

• Megasporangium

• Integument

What are the components of a seed?

• Seed Coat

• Spore wall

• Food supply

• Embryo

Importance

• source of lumber, food, resins, dyes, tannins, medicine

• ornamental decor

• preservation and historical value (amber)

Which structures are in the SPOROPHYTE generation?

• Seed

• Ovule

• Megasporangium

• Seed coat

• Embryo

Which structures are in the GAMETOPHYTE generation?

• Pollen grains

• Micro/megagametophyte

• Archegonium

• Egg