Download Seed Plants - Biology Department

Seed Plants
BSC 2011L
Seed Vascular Plants
 Among
plants, these include the gymnosperms
and angiosperms
Reproductive differences in seedless
vs. seed plants

Sporangia


Protection of egg



Non- seed plants utilize an archegonium on the gametophyte to protect
egg, sporophyte develops within archegonium
Seed plants protect entire gametophyte within ovule (which will develop
into seed)
Transport of male gametophytes



Seed plants have 2 types: megasporangium, microsporangium
Non-seed plants – use water for flagellated sperm
Seed plants – male gametophyte carried by wind (pollen)
Sporophyte vs. gametophyte


Non-seed – sporophyte dependent on gametophyte
Seed – gametophyte dependent on sporophyte
Plant Taxonomy, continued
 Refer
to previous PowerPoint for Seedless plant taxonomy
 Domain Eukarya

Kingdom Plantae





Phylum Cycadophyta
Phylum Ginkgophyta
Phylum Gnetophyta
Phylum Coniferophyta
Phylum Anthophyta


Class Eudicots
Class Monocots
Cycads
Ginkgos
Gnetophyta
Conifers
Flowering Plants
Dicots
Monocots
Gymnosperms
 “Naked

Seed”
Ovules and seeds of gymnosperm are exposed on
cone scale
 Microsporangia
and megasporangia located on
different cones, sometimes different plants
 Female
cones are larger than male cones
Gymnosperms
Cycads
 Cone-bearing,
palmlike plants found mainly in
tropical and subtropical regions
Gymnosperms
Ginkgos
 Only
1 species survives today
 Usually only male trees are used since female
trees produce smelly seeds
Gymnosperms
Gnetophytes
 Can
grow as shrubs, trees, or vines
Gymnosperms
Conifers
 Largest
group of gymnosperms
 Evergreens – pines, hemlocks, spruces
 Nonevergreens – cypress tree
Gymnosperms
Pine life cycle
Gymnosperms
Pine Cone
 Female
 Male
– small “dots”
are pollen
Angiosperms
 Dominant
plants today
 “Flowering Plants”
 Microsporangia and Megasporangia
located on same flower
 Double Fertilization

Mature pollen grain contains 2 sperm


1 fertilizes egg
Other joins 2 polar nuclei to form endosperm
(food for embryo)
Angiosperms
Monocots vs. Dicots
Quiz yourself
Angiosperms
Life Cycle
Angiosperms
Seed Germination
Angiosperms
Fruits
 Develops

from ovary
Ovary wall thickens to be pericarp

3 layers




Exocarp – skin of fruit
Mesocarp – fleshy part
Endocarp – boundary around seed
Review Dichotomous key on page 287
• Angiosperms
Fruits
•
Simple Fruits (develop from
single ovary)
•
Aggregate Fruits (develop from
numerous ovaries within a single
flower)
• Blackberries
• Raspberries
• Strawberries
•
Multiple fruits (develop from a
number of ovaries of several
flowers)
• Pineapples
• Mulberries
• Figs
Fleshy fruits
•
•
•
•
Drupes – cherry
Berries – grape, tomato
Pomes – apple
Dry fruits
•
•
•
•
•
•
Legumes – pea
Samaras – maple
Nuts – oak, walnut
Grains – wheat, corn
Achenes -- sunflower,
dandelion