Topic 16 Flashcards
____ are the dominant primary producers in terrestrial ecosystems
Gymnosperms
____ consist of an embryo and nutrients surrounding in a protective coat
Seeds
Shared derived traits of seed plants
Reduced gametophytes
Heterospory
Ovules
Pollen
Seeds
Do seed plants have independant or dependant gametphyte compared to bryopytes
Dependant gametophyte
What does reduced gametophyte cause in plants
A reduction in size and independance sompared to the spropophyte.
All seed plants are _____
Heterosporous
_______ produce _____ that produce male gametophytes
Microsporangia
Microspores
_____ produce _____ which pgive rise to female gametophytes by meiosis
Megasporngia
Megaspores
Where are spores located in a seed plant
They are retained in the sporophyte and not dispersed in seed plants
What does an ovule consist of?
Megasporium (2n), megaspore (1n) and one or more protective integuments (2n)
Gymnosperms have ____ integument,
Angiosperms usually have ____ integument
One
Two
Ovules develop into seeds after ___
Fertilization
A megaspore is enclosed in a protective ____
Integument
Are megaspores dispersed? And why?
No because they are retained in protective integument tissue
____ develop into male gametophytes within ____ _____
Microspores,
Pollen grains
Does pollen grain = male gametophyte?
No because pollen grains carries the male gametophyte
Microsporangium (2n) produce microspores (1n) by what process?
Meiosis
Microspores undergo ___ to produce tiny male gametophytes
Mitosis
what do pollen grains contain in seed plants?
- male gametophyte
- generative cell
- tube cell
What happens to the generativecell and the tube cell after polllination?
These structures become the sperm nuclei and a pollen tube
Are microspores dispersed?
No, they develop into pollen grains
What does a seed contain generation wise?
The next generation sporophyte. The outer shell contains the previous generation
What does pollination help transport
Helps transport pollen to the ovule for fertilization
Do seedless plants require water for fertilization?
Yes
What happens when the pollen grain germinates?
Give rise to a pollen tube that discharge sperm nuclei (without flagella) into the female gametophyte in the ovule
Seeds are the dispersal stage for seedless plants, true or false?
False, this statement only applies to seed plants
Are seeds in seed plants more advantageous than spores
Yes, seeds are larger in size compared to spores
Two clades of seed plants
Gymnosperms (naked seeds) and angiosperms
List the four phyla of gynosperms, are they monophyletic or paraphyletic?
Cycadophta, gingkophyta, gnetophyta, coniferophyta
Monophyletic
Traits of phylum cycadophyta
- used to be diverse and demoninant (in mesozoic period) but are now small populations in the tropics and many species are endangered
- grow very slowly
- have larger palm-like leaves and short unbranched stems
- have flagellated sperm (like ginkos)
Traits about phylum ginkophyta
- only one species
- have bi-lobed leaves (heart shaped)
Have male and female sporophyte that are wind pollinated - flagellated sperm
- no wild populations
Traits about phylum gnetophyta
- have three genera
- porphologically diverse are are adapted to many environments
Traits of phylum coniferophyta
- many are evergreens
- don’t drop leaves in autumn, some do (deciduous)
- adapted to cold , dry habitats
- have thick cuticles, reduced leaf surface area
- xylem tissues have resistance to collapsing
What are the three key features of gynosperm life cycles
- dominant sporophyte generation
- develop seed from fertilized ovules
- transfer male gametophytes by pollen
(They are seed plants)
