Seed plants (Chapter idfk)

what are the key characterisitcs of seed plants?

• Are the most extant plant species

• Have reduced male and female gametophytes

• Are heterospores as they have male and female gametophytes

what are the two types of seed plants?

• gymnosperms

• angiosperms

what do all seed plants have?

reduced gametophytes

what are the two types of spores produced by seed plants?

• Microspores (male)

• Megaspores (female)

what does each microspore develop into?

A grain of pollen

what is pollen?

A male gametophyte enclosed within a wall of sporophyte cells

what is pollination?

the transfer of pollen to the part of a seed plant containing the ovules

• ovules being the female part of a plant

how can pollen be transferred?

It can be transferred long distances by wind or animals

what is an ovule?

A megaspore within a megasporangium surrounded by one or more integuments

• Angiosperm has two integuments

• gymnosperms have one integuments

what develops from a megaspore?

female gametophyte

what are seeds?

Embryos packaged with nutrients supply inside a protective coat

• all seed plants produce these (wow really????? :0)

what are some characteristics of seeds?

• Can disperse over long distances by wind or other means

  • ex: animals

• Provides protection from harsh conditions and can remain dormant for years until favorable conditions are met

• Have food supply to nourish seedlings

what is a function advantage that seeds have compared to spores?

contain a nutrient store for a developing sporophyte

what are gymnosperms (“naked seed”)?

A type of seed plant that produces seeds that dont mature within enclosed chambers

what are some characteristics of gymnosperms?

• Most are wind pollinated

• Dominated during the mesozoic era (circa 250 to 60 mya) and were food for dinosaurs

• Still dominate in some regions

  • Ex: coniferous forests in northern latitudes

• Consists of four phyla

what are the four phyla that gymnosperms consist of?

• Cycads

• Ginko’s

• Gnetophytes

• Conifers

what are the characteristics of cycads?

• They have large cones and palm like leaves

• they have flagellated sperm unlike most seed plants

• Tend to be pollinated by beetles

• Thrived during the mesozoic era

  • but there aren’t many today and are endangered

what are the characteristics of Ginko’s?

• There are only one living species: Ginkgo biloba

• Have flagellated sperm

• They are popular in cities due to their high tolerance to air pollution

what are the characteristics of Gnetophytes?

• Some are tropical and some live in deserts

• Have three genera that appear very different, but are linked molecularly

  • Genera: a taxonomic rank used to group closely related species (dont have to know this but here so you know what it means :p)

what are the characteristics of conifers?

• The largest group of gymnosperms

• Most of them are evergreen and retain leaves year round

what are angiosperms (“covered seed”)?

A type of seed plant that produces seeds that mature inside chambers within flowers

what are characteristics of angiosperms?

• Originated around 140 million years ago in the cretaceous era

• 90% of extant plant species are angiosperms

• They are animal, wind or self pollinated

• They all belong to one phylum (anthophyta)

what are the 2 key adaptations of angiosperms?

• flowers

• fruits

what are flowers? (yeah i gotta ask this-)

they are specialized shoots used for sexual reproduction with most parts being modified leaves that evolved into specialized structures

what are a flowers specialized structures?

• Sepal: Encloses flower buds

• Petals: Have bright colors to attract pollinators

• Stamen: microsporophyll’s and are the male reproductive parts

  • consists of filament and anther

• Carpel: megasporophyll’s and are the female reproductive parts

  • consists of stigma, style, ovary

    • Stigma being sticky and receiving pollen

    • Ovary having ovules that develop into seeds after fertilization

what are fruits?

The mature ovary of a flower that protects seeds and aids in their dispersal

what are some various adaptations that aid fruits in angiosperm seed dispersal?

• fruits with wings

• seeds within berries

• fruits with barbs

what are the four primary groups of angiosperms in order of evolution?

• Basal angiosperms

  • Ex: Water lily

• Magnoliids

  • Ex: Southern magnolia

• Monocots

  • Ex: orchid, pygmy date palm, wheat

• Eudicots

  • Ex: strawberries, roses

what are monocots?

Plant embryos that have one seed leaf called cotyledon

what are eudicots?

Plant embryos that have two seed leaves with most angiosperms belonging to this group of plant embryos

why are seed plants important?

they are key sources of food, fuel, and wood products

why are angiosperms important?

• angiosperms (such as wheat, rice, maize, potatoes, cassava, and sweet potatoes) provide 80% of human calories

• they include grains which feeds livestock

• they include other edible products

  • such as: tea, coffee, chocolate, spices

how are seed plants helpful in medicines?

medicinally active compounds in seed plants are used directly or synthesized to produce medicines