Post on 29-Dec-2015
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The Diversity of Plants
Unit 7
Chapter 22
Nonvascular plant habitat
Near water source
Nonvascular plant size
Because nonvascular plants do not have xylem and phloem, they depend on diffusion to get water and nutrients to each cell.
Consequently, nonvascular plants cannot be large because cells farther away from a water source would die..
Rhizoids
Structures that are similar to roots that anchors and absorbs nutrients for the nonvascular plant
Alternation of generation life cycle
Antheridium: male structure that produces sperm
Archegonium: female structure that produces egg
Sperm + egg zygote
Alternation of generation life cycle
The zygote grows into a plant structure called a sporophyte.
The sporophyte produces spores by meiosis.
The spores grow into a plant structure called a gametophyte.
Alternation of generation life cycle
The gametophytes are either male or female. Male: antheridium Female: archegonium
Prothallus
The fern gametophyte body that develops male (antheridia) or female (archegonia) reproductive structures
Sorus on fronds
Structures underneath the frond leaflets of fern plants are called sorus.
These structures produce spores that germinate to form the prothallus.
Cones
The structures that bear the male and female reproductive parts in gymnosperms (exposed seed, vascular plants) that produce sperm and egg are called cones.
Most associate cones with pine trees.
Large cycad cone
Pollen grains
The male gametophytes of seeded plants are pollen grain, which are sperm and nutrients packaged within a protective coat.
These structures carry sperm cells to an egg.
Pine pollen grain with air pockets to help the structure stay afloat in the air
Pollen grains in flowering plants
Flowering plants produce pollen grains within the male reproductive structures on flowers.
Ovule in flowering plants
The ovule is a protected structure that produces eggs.
Seed development in flowering plants
Sperm + egg zygote The zygote develops into an embryo found
within a seed. The seed may have one or two structures
(cotyledons) that store food. Monocot: plants that make one cotyledon
seeds Dicot: plants that make two cotyledon seeds
Dicot seed germination (ex: bean)
Fruit
Only plants that produce flowers produce fruits.
The fruit is a covering that either helps the seed fly through the air or entices animals to eat the fruit to disperse the seeds.
Evergreen vs. deciduous plants
Evergreen: plants that retain leaves over winter
Deciduous: plants that drop leaves over winter
evergreen
deciduous
Annual plants
produce seeds that survive harsh winters, but parent plant dies after one year
Biennial plants
Life cycle lasts two generations (years) Year 1: develop root system, storing sugars Year 2: flowers, fruits, and form seeds
Perennial plants
Plants that live for multiple years, continuously producing viable seeds
Usually during winter, leaves drop but the wood stems survive.