Test 3; Plant Structure and Function
Bryophyte (3 traits)
1) *lack vascular tissue* 2) have specialized reproductive organs 3) Quite small (only a few cm), making them poor competitors for light and space with vascular plants
4 major evolutionary transformations in life cycle and structure of plants (in order)
1) Evolution of alternation of generations 2) Evolution of vascular plants 3) Evolution of Pollen as seeds 4) Evolution of flowering plants
How do nonvascular plants differ from vascular? (5)
1) No roots,stems or leaves 2) No water/nutrient transport system 3) Take in water thru osmosis only 4) Small because of lack of support structures 5) Need water for reproduction
In which 2 cells (in which order) does C4 photosynthesis take place
1st- mesophyll, 2nd- bundle sheath
How many species of plants are present today? What percentage are angiosperms?
400,000 species approximately 90% are angiosperms
What percentage of plants are Vascular Plants
95%
Examples of C3 plants
95% of plants Namely, the Cherokee Rose (GA state flower) Picture is the Cherokee Rose
Double fertilization What is its advantage?
A fertilization process that requires two sperm to fuse with two other cells Conserves resources until the egg is actually fertilized
angiosperm
A flowering plant which forms seeds inside a protective chamber called an ovary.
Ferns and Horsetails
A monophyletic group of vascular plants that have leaves and disperse by spores. (fern is on right in picture)
Plant
A multicellular member of the kingdom Plantae that typically produces their own food through photosynthesis and contains cell walls
Gymnosperms
A plant that produces seeds that are exposed rather than seeds enclosed in fruits
CAM photosynthesis
A system that limits water loss by only opening the stomata at night to capture CO2.
Evergreen How do they stay green?
A type of forest in which most of trees have green leaves throughout the entire year because they don't shed their chlorophyll a (which reflects green light)
Selective advantage of pollen and seeds
Allows plants to disperse their genetic material without the need of water
Monocot
An angiosperm that has only one seed leaf.
Dicot
An angiosperm that has two seed leaves
Aquatic Fern
Azolla- a free flowing aquatic fern Used in rice paddies in Asia as a biofertilizer because of its symbiosis with N fixing bacteria Used to suppress weed growth and provide N to rice paddies
Why may angiosperms have been necessary for the formation of tropical rainforests?
Because of their high rates of transpiration, lower temperatures and higher rainfall occurred
Why are giant lycophytes a major source of energy
Because so many of their massive carcasses decomposed in the swamps and formed coal
Why is bryophyte size limited? From where must they absorb nutrients?
Because they lack lignified xylem conduits They must absorb water, nutrients, and CO2 from their surfaces
When did aquatic plants transition to land?
Between 400-500 million years ago
Two Groups of Land Plants
Bryophytes and Vascular Plants
3 Types of Photosynthesis
C3, C4, CAM
Orchids What type of photosynthesis (don't need to know)
CAM photosynthesis This makes them resistant to drought
In what climate is CAM photosynthesis utilized? What types of plants utilize it?
Climate- Desert climates Types- those that grow without soil Ex- cacti
Cycad
Date back 270 myo a division of gymnosperms that grow in tropical climates and resemble palm trees have fleshy seeds
Selective advantage of angiosperm fruits
Fruits protect developing seeds
What is the last common ancestor of all land plants?
Green Algae
2 Examples of seed plants
Gymnosperms and angiosperm
Giant Lycophytes What was their structure and why did they go extinct?
Had thick bark and lived in swampy environments Went extinct when the climate changed and the swamps dried up
Conifer
a cone-bearing tree Tallest, oldest trees on earth Include pines and evergreens
Ginkgo
a division of gymnosperms with only one living member (270 myo) have fleshy seeds
hornwort
a group of bryophytes in which stomata appear
sporopollenin
a layer of durable polymer that prevents exposed zygotes from drying out
Epiphyte (don't need to know)
a plant that uses another plant for support, but not for nourishment
Lycophyte
aka club moss; dominated millions of years ago Spore plants with only one vein Sister group of all other vascular plants
Why can non-giant lycophytes not become fuel?
because a large mass is needed to be a good source of energy
What is the selective advantage of vascular tissue (2)
It allows faster transport of nutrients than osmosis AND provides structure and support
What is the selective advantage of alternation of generation
It enhanced seed dispersal on land because of the sporophyte generation and resistant spores
5 Examples of vascular plants
Lycophytes (club moss), ferns, and horsetails Gymnosperms and angiosperms
3 examples of seedless plants that reproduce with spores
Lycophytes (club mosses), ferns, and horsetails
What type of phyletic group are land plants?
Monophyletic
Where does C3 occur? How many stages are there?
Occurs in the chloroplast Only 1 stage
In what climate is C4 photosynthesis utilized? 3 specific examples of plants
Plants in hot, dry climates Corn, pineapple, and sugarcane
What kind of seeds do gymnosperms have?
Pollen This means they need no external water source
C3 photosynthesis
Produces a 3-carbon compound during the Calvin Cycle
Why are plants important
Provide oxygen, food, medicine, fuel, shelter, paper products, beauty
Selective advantage of angiosperm flowers
The flowers increase the efficiency of pollen transfer and probability of fertilization
C4 Photosynthesis
The two-stage process Requires low water and light and creates a lot of energy
How do bryophytes avoid damage to their tissues from a dry environment?
Their membranes are able to withstand the desiccation and rehydration of the cells without rupturing.
How does bryophyte sperm move?
Their sperm swims so they need water for fertilization
What is special about angiosperm vascular systems?
They have multicellular xylem vessels which can transport water through their stems at higher rates than plants with single-celled tracheids
How can conifers survive extreme environments? (2)
They have thick, waxy cuticles making their leaves waterproof to preserve water Also, they have needle-like leaves, letting them survive better in harsher, colder conditions than broad leaves
Tree Fern
They have vascular tissues that let them grow about 10 meters tall with thick roots for more support and vascular capacity They cannot grow more because they have no secondary growth
How did the plant methods of reproduction adapt to dry conditions with intense sunlight
They moved from swimming sperm to airborne pollen
How do seed plants reproduce?
They release seeds and pollen
How do seedless plants reproduce?
They use spores and rely on swimming sperm for fertilization
Where are conifers found?
Usually in higher elevation and dryer areas North America and Australia
Where are gymnosperm seeds made
Usually on cones
4 major groups of plants
mosses, ferns, gymnosperms, angiosperms
3 types of bryophytes
mosses, liverworts, hornworts
2 groups of vascular plants
seedless and seed plants
2 benefits of seeds over spores
survive better than unprotected spores, can be transported long distances The nutrients in the seed make it more likely that the embryo will grow to a plant
Cavitation
the formation and expansion of gas bubbles in the xylem.
liverwort
the most primitive group of bryophytes
moss
tiny leafy-stemmed flowerless plants
Examples of non vascular plants (1 with 3 subgroups)
*Bryophytes* LiverWorts, Hornworts, and Mosses
What happens during the day and night of CAM photosynthesis
*Day-* stomata is closed, sunlight is absorbed *Night-* stomata is open, CO2 is absorbed and fixed
Where do plants get their 3 necessary materials from
*Light-* From the sun *CO2-* From the surrounding atmosphere *H2O-* From the soil
Spanish Moss
*NOT* a moss, but in fact a lichen (symbiotic fungi)