vascular seed plants
DESCRIPTION
Vascular Seed Plants. Plants that plan ahead…. Seeds – Overview and Structure. Seed plants, perhaps unsurprisingly, produce… seeds. A seed is a structure that contains: An immature sporophyte (remember – sporophytes often become the BIGGEST part of a more complex plant). - PowerPoint PPT PresentationTRANSCRIPT
Vascular Seed PlantsPlants that plan ahead…
Seeds – Overview and StructureSeed plants, perhaps unsurprisingly, produce… seeds.
A seed is a structure that contains: An immature sporophyte (remember –
sporophytes often become the BIGGEST part of a more complex plant).
Food (carbs and fats) to keep it alive until it finds suitable growth conditions.
Types of Vascular Seed Plants Further broken into two major groups:1. Gymnosperms
Plants whose seeds are “exposed” (gymno = “naked”) as they develop on the mature sporophyte.
2. Angiosperms Plants whose seeds develop in a closed
ovary (this later develops into a fruit).- You read that correctly. We eat a balanced diet that includes a healthy amount of plant ovaries. Eat up!
Gymnosperms‘tis the season!
Gymnosperms – Typical organisms Coniferous trees – trees that put out
cones that will store spores. Eg: Spruce, pine, and fir Found in nearly every climate (guess
where it isn’t found!)
Typical Orgnisms cont’d Ephedra sp. – smaller shrubs; produce
compounds that have well-known medicinal uses.
Increase metabolism, heart rate, and ventilation (breathing). Used to be used as performance-
enhancing drugs. Now banned in the US; highly controlled
in Canada.
Typical Organisms cont’d Cycads – resemble short, shrubby palm
trees. Date back to the same era as the
dinosaurs.The Nomosaurus enjoying a light
gymnosperm salad. Entrée of sauteed
simians soon to follow.
Gymnosperm Structure Needle-like leaves – small surface
area, prevents loss of water and nutrients. Many (NOT all) gymnosperms are
“evergreens” – don’t drop their leaves.
Structure cont’d
Has roots which are seldom deep but cover a large area.
Produce cones which store and protect either male or female spores.
Structure cont’d Gymnosperms are adapted for life on
land. Water needed for nutrition only – not for
reproduction. Pollen can “fly”.
Gymnosperm Reproduction(Using conifers as our example) Mature conifers make both male AND female
cones. Produce two types of spores – male and
female, respectively. Male spores = pollen; these spores are
released. Female spores NOT mobile. Remain in their
cones. Fertilized by pollen that lands upon them.
Gymnosperm Reproduciton
AngiospermsFlower power, yo!
Angiosperms - Overview All produce a flower (not necessarily a
pretty one). Adapted to rely on a variety of
pollinators:1. Wind2. Insects3. Larger animals Enclose their seeds for protection (often
in a fruit).
Angiosperm classification Angiosperms are divided into two main
groups. Grouping is based on how many
cotyledons (“seed leaves”) the plant makes. These are the first leaves the plant will make.
1. Monocots produce one cotyledon.2. Dicots produce two cotyledons.
Monocot VS DicotMonocots and dicots differ with respect to other features, too. These include: Arrangement of xylem and phloem Structure of “veins” in the leaves Arrangement and structure of flowers
Monocot VS Dicot
Angiosperm Reproduction Happens through pollination (sexual). Involves male and female gametes.
The male gametes are always those that actually move from one place to another.
Angiosperm Reproduction cont’d Some angiosperms carry BOTH male
and female structures. Called monoecious plants
Angiosperm reproduction cont’d Other angiosperms only produce
structures for a single gender (only male or only female). These are called dioecious plants.
Angiosperm Reproduction cont’d
Angiosperm Reproduction cont’d Pollination leads to formation of seeds.
Seeds can spread through a few ways:1. Attaching to animals (uses hooks and
spines)2. Seed explosions3. Wind dispersal (using wings or
“parachutes”)
Angiosperm Reproduction cont’d4. Water5. Animal digestion (from eating fruit)