What are the closest relatives of plants?
Green algae (charophytes)
Plants share a common ancestor with charophytes but are not directly descended from them.
Name the three key traits that land plants share with charophytes.
- Rings of cellulose-synthesizing complexes
- Structure of flagellated sperm
- DNA similarities
These traits highlight the evolutionary relationship between land plants and charophytes.
What is sporopollenin?
A polymer that prevents zygotes/spores from drying out
It is crucial for the survival of plant reproductive structures in terrestrial environments.
List the four key traits that appear in nearly all land plants but are absent in charophytes.
- Alternation of generations
- Multicellular dependent embryos
- Walled spores produced in sporangia
- Apical meristems
These traits are essential for the adaptation of plants to land.
Define alternation of generations.
A reproductive cycle where plants alternate between multicellular haploid (gametophyte) and diploid (sporophyte) stages
This cycle is fundamental to the life history of plants.
What are apical meristems?
Localized regions of cell division that sustain continual growth
Cells from apical meristems differentiate into various tissues.
What is the function of stomata in plants?
Specialized openings that allow for gas exchange
Stomata are crucial for photosynthesis and respiration.
What are Non-Vascular Plants?
Nonvascular plants, including Hepatophyta (liverowrts), Anthocerophyta (hornworts), and Bryophyta (mosses)
Bryophytes are characterized by their lack of vascular tissue.
True or false: In nonvascular plants, sporophytes are dominant and independent.
FALSE; they are gametophyte dominant
In bryophytes, sporophytes are dependent on gametophytes and are typically smaller.
What are the two phyla of seedless vascular plants?
- Phylum Lycophyta
- Phylum Monilophyta
These phyla include various types of vascular plants that reproduce via spores.
What is the significance of vascular tissue in plants?
Allows plants to grow tall and transport water and nutrients
Vascular tissue includes xylem and phloem.
Define homosporous.
Producing one type of spore that develops into a bisexual gametophyte
Most seedless vascular plants are homosporous.
What are microphylls and megaphylls?
- Microphylls: Leaves with a single vein
- Megaphylls: Leaves with a highly branched vascular system
These types of leaves are adaptations for increased photosynthesis.
What is the role of roots in vascular plants?
Anchor plants and absorb water and nutrients from the soil
Roots may have evolved from belowground stems.
What are the key traits of Non-vascular Plants?
-Gametophyte dominant and non-vascular
What’s a cuticle ?
a waxy covering of the epidermis that reduces water loss
When spores germinate into a gametophyte what is it composed of?
Protonema
What is a sporophyte?
Makes spores
What are the 3 ecological roles of non-vascular plants?
Retain nitrogen in the soil, used a fuel from peat, contains 30% of the worlds soil carbon
Traits of Seedless vascular plants?
Seedless and Vascular tissue
Which transport tissue is dead and carries water and minerals? Also has lignin?
Xylem
What does vascular tissue do for plants?
Increases height
What are the ecological significances of seedless
