Plant Diversity 2 Part 2 Flashcards
Before the bryophytes what happened?
Embryonic attachment to the mother plant
What happened before pteridophytes?
Cells joined in tubes for water and nutrient transport; vascular tissues
What happened before gymnosperms and angiosperms?
The seed stage
Seed
A sporophyte embryo and nutrients surrounded by a protective coat
Heterospory
Ancestors of seed plants were homosporous while seed plants are heterosporous
Microspores
Produce male gametophytes
Megaspores
Produce female gametophytes
Megasporangia
Are diploid and produce megaspores
Microsporangia
Are diploid and produce microspores
Reduced gametophytes
Occur in vascular plants; provides protection as the gametophytes of seed plants develop within the walls of spores that are retained within tissues of the parent sporophyte
Ovules
Include integument+megasporangium, megaspore/egg
Difference between gymnosperm and angiosperm megasporangia.
Gymnosperm has one integument and angiosperms has two
Pollen
Microspores develop in pollen grain which contain male gametophytes; also eliminates need for water and can be dispersed great distances by air or animals
Pollination
Transfer of pollen to part of seed plant contain ovules
Pollen tube
Discharges two sperm to female gametophyte within ovule after pollen grain germinates
What evolutionary advantages do seeds provide?
Can be transported long distances by wind or animals and may remain dormant for days to years until germination
What are the four species of gymnosperms?
Coniferophytes, gnetophytes, ginkophytes, and cycadophytes
Phylum Ginkgophyta
One species; high tolerance to air pollution and popular ornamental tree
Phylum cycadophyta
200 species; palm like, seeds produced in large cones, few exist today
Phylum gnetophyta
Diverse (several growth forms but few species); vary in appearance, some are tropical and some are in deserts
Phylum coniferophyta
550 species; include: pines, firs, redwoods, spruces, etc.; needle shaped leaves, mostly evergreen, important ecologically and economically
Difference between small and large cones?
Small cones have male gametophytes and large cones have female gametophytes
Transition from charophyceans to vascular plants with seeds
Less reliance on water and increasing dominance of sporophyte generation
Anthophyta
All angiosperms in one phylum; flower
Flower
Unique structure to angiosperms that is for reproduction
Sepals (calyx)
Cover immature flower bud
Petals (Corolla)
Brightly colored and attract animals for pollination
Stamens
Microsporophylls produce microspores which make male gametophytes in the six anthers
Carpels
Megasporophylls that make megaspores which contain female gametophytes and make seeds; includes the stigma
Fruit
Consists of a mature ovary and protects seeds and aids in dispersal
Why are angiosperms more diverse?
Rapid life cycle, symbioses with other species, more effective vascular tissue (sieve tube members)