Seed Plants-Gymnosperms Flashcards
What was key for life on land?
Seeds and pollen
-They disperse over long distances by wind/animald
What are reproductive adaptations of plants?
Flowers and fruits
What are the two types of seed plants?
Gymnosperms
-naked seed
Angiosperms
-enclosed seed
-flowers
Common traits of seed plants
- Reduced gametophytes
- Heterosporous
- Have an ovule with a megasporangium, megaspore, and one or more integuments (for protection)
Megasporangia
Produces megaspores that give rise to female gametophytes
Microsporangia
Produces microspores that give rise to male gametophytes
How many integuments do gymnosperms and angiosperms have?
G: One integument
A: Two integuments
What are the advantages of having reduced gametophytes?
- Protection from environmental stresses
- Ovule protects from UV
- Can obtain nutrients from parent plant
Microspores develop into?
Pollen grains
Pollination
The transfer of pollen grains from the male anther to the female stigma
What does pollen eliminate the need for?
Water
If a pollen tube germinates, it gives rise to?
A pollen tube
-discharges sperm into female gametophyte in the ovule
Why are seeds advantageous over spores?
- They can remain dormant until the conditions are favourable for germination
- Seeds have a supply of stored food
- Can be transported by wind or animals
Where are the seeds exposed on cones in gymnosperms?
On sporophylls
-scales
-Not encased in an ovary
A ___ is a sporophyte embryo along with its food supply, and a protective coat
Seed
What are the three key features of the gymnosperm life cycle?
- Dominant sporophyte
- Seeds
- Pollen
What is the largest gymnosperm phyla?
Coniferophyta
