Plants 3 Lecture Flashcards
What are tracheophytes?
Plants that have vessels including vascular plants and seed plants
What plants ruled the world before vascular plants?
Nonvascular plants(very small plants)
What challenges did nonvascular plants have that led to vascular plants?
- competition (space, light, water, nutrients)
- Could not colonize dry environments
- Could not be tall
- Could not go very deep (no roots)
Key Innovation 1: Branching (Positive impacts?)
- Plants could diversify their shapes and compete better for light
-Plants could specialize (branch out and compete for light or branch underground(better for nutrients) - Allowed for better dispersal (spores were placed at tips of branches and wind could more easily move spores)
What is Modularity?
A plants ability to regrow important features(ex. cutting a branch then it grows back)
What was the first example of modularity?
Branching
What was bad about the cuticle?
Prevented mosses from drying out but also made plants waterproof and unable to exchange gas
What is a Stomata?
Opening on the surface of leaves where the plant can control the passage of water and gasses by opening and closing the stomata
Advantages of the Stomata?
- Allowed plants to live in drier environments because plants could control photosynthesis and water loss depending on their environment (ex. Close stomata during a drought so no water escapes, open stomata when doing photosynthesis to allow CO2 to enter)
Did the cuticle or stomata come first?
Cuticle was developed first however no bryophytes could have a full cuticle as photosynthesis could not occur. Therefore, the full cuticle was invented after the stomata
Why are stomata on the bottom of leaves?
To allow for less water evaporation from the sun when the stomata open
What is vascular tissue and its two functions?
Vascular tissue is a specialized reinforced conductive tissues. Its two functions are for structural support and the transportation of waters, sugars and nutrients up and down the plants body
Types of vasculature
Xylem: hollow water conducting cells
Phloem: Vascular tissue that conducts sugars
Functions of roots?
- Nutrient and water acquisition(obtaining)
2.Physical Support
Roots and Mychorrhizal
Roots allowed for plants to live in symbiosis with mycorrhizal fungi. Mycorrhizae combine their mycelium with plant roots to help them expand and get more nutrients
Nonvascular plants vs Vascular Plants
Nonvascular: Gametophyte dominant life cycle, very small sporophytes/short lived
Vascular: Sporophyte dominant life cycle, large sporophyte
Advantages of the Sporophyte dominant life cycle
Twice as much DNA
- Having two copies of a gene, specifically heterozygous(each parent) increase the amount of potential depression of traits to adapt to an. environment
- If you have a mutated gene from one parent the same gene from the other parent can mask the mutated gene.
Explain the sporophyte dominant life cycle (see images pg.2)
1.On the underside of the leaves is where spores undergo meiosis(2n to n)
2.The spores are then dispersed by wind
3.Spores develop into tiny gametophyte then fertilization occurs, ferns have motile sperm(need water for sperm to swim to the egg)
4.Fertilization leads to 2n zygote which matures to sporophyte
Evolutionary Stasis
Ferns look similar to how they looked when they first evolved
Bioremediation
Growing ferns on a contaminated site and then the ferns remove the heavy metals and then are dug up and burned
