Plants 3 Lecture

Question 1

What are tracheophytes?

Answer 1

Plants that have vessels including vascular plants and seed plants

Question 2

What plants ruled the world before vascular plants?

Answer 2

Nonvascular plants(very small plants)

Question 3

What challenges did nonvascular plants have that led to vascular plants?

Answer 3

• competition (space, light, water, nutrients)
• Could not colonize dry environments
• Could not be tall
• Could not go very deep (no roots)

Question 4

Key Innovation 1: Branching (Positive impacts?)

Answer 4

• 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)

Question 5

What is Modularity?

Answer 5

A plants ability to regrow important features(ex. cutting a branch then it grows back)

Question 6

What was the first example of modularity?

Answer 6

Branching

Question 7

What was bad about the cuticle?

Answer 7

Prevented mosses from drying out but also made plants waterproof and unable to exchange gas

Question 8

What is a Stomata?

Answer 8

Opening on the surface of leaves where the plant can control the passage of water and gasses by opening and closing the stomata

Question 9

Advantages of the Stomata?

Answer 9

• 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)

Question 10

Did the cuticle or stomata come first?

Answer 10

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

Question 11

Why are stomata on the bottom of leaves?

Answer 11

To allow for less water evaporation from the sun when the stomata open

Question 12

What is vascular tissue and its two functions?

Answer 12

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

Question 13

Types of vasculature

Answer 13

Xylem: hollow water conducting cells
Phloem: Vascular tissue that conducts sugars

Question 14

Functions of roots?

Answer 14

1. Nutrient and water acquisition(obtaining)
   2.Physical Support

Question 15

Roots and Mychorrhizal

Answer 15

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

Question 16

Nonvascular plants vs Vascular Plants

Answer 16

Nonvascular: Gametophyte dominant life cycle, very small sporophytes/short lived
Vascular: Sporophyte dominant life cycle, large sporophyte

Question 17

Advantages of the Sporophyte dominant life cycle

Answer 17

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.

Question 18

Explain the sporophyte dominant life cycle (see images pg.2)

Answer 18

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

Question 19

Evolutionary Stasis

Answer 19

Ferns look similar to how they looked when they first evolved

Question 20

Bioremediation

Answer 20

Growing ferns on a contaminated site and then the ferns remove the heavy metals and then are dug up and burned