Lecture 2 RH Flashcards
What does the light-dependent transfer of electrons from H2S to NADPH indicate?
Early photosynthesis
What are the major evolutionary events that led to modern plants?
- 5bya prokaryotes
- 5bya eukaryotes
650mya multicellilar eukaryotes
475mya Sea to land
420mya Vacular plants
360mya Seed plants
125mya angiosperms
What are streptophytes?
Collective group for the closest relatives to land plants.
This group includes the embryophytes
What are embryophytes?
Embryo is protected
What does it mean when plants are said to be monophyletic?
Every plant ultimately shares a common ancestor
Why is it a big deal that plants developed vascular structures?
They are able to grow larger
What are bryophytes?
All embryophytes (land plants) that do not have true vascular tissue and are therefore called “non-vascular plants”.
What are the closest living relatives to land plants?
Charophytes are the closest living relative to land plants
What happens to dominance in plants?
Evolution shows a gradual reduction in the length of time where gametophytes are dominant and an increase in time where sporophyte dominance.
How are algae similar to early plants?
Algae are typically haploid like gametophytes which are dominant in early plants
What are the types of bryophytes?
Mosses
Liverworts
Hornworts
What are the male and female organs of plants?
arcigonium
antheridia
When do bryophytes typically produce spores? Why?
When the weather is dry because fertilization relies on sperm reaching eggs via water droplets
What does it mean when a plant is monoecious?
Antheridia and arcigonia can be on the same gametophyte
What is the alternation of generations?
Alternation between sporophyte and gametophyte seen in plants
What is the difference between the lineage of the bryophytes and the Pteridophytes? What does this mean?
Lineage which produced bryophytes branched early and didn’t give vascularity. Pteridophytes continued evolving to form gymnosperms and in turn angiosperms. (gymnosperms diverged and angiosperms formed separately)
They all have a common ancestor. (i.e algae)
What are the characteristics of bryophytes?
They lack vascular tissue so they are small
Grow in clumps or masses
Capable of prolonged dehydration
Occur in moist habitats
Lack cuticle
Disperse via spores
Require water for sexual reproduction
Alternation of generations
Which of the generations is dominant in bryophytes?
in bryophytes gametophyte is dominant and sporophyte is dependent.
What features do bryophytes share with green algae?
They have dominant chlorophyl a+b and are photosynthetic.
They also store energy in the form of starch.
They have phragmoplast
What is the largest moss?
Dawsonia Superba (dandenongs)
What are the unique morphological details of mosses, liverworts, and hornworts?
Mosses are all leafy types.
Liverworts can be leafy or thalloid types
Hornworts are all thalloid types
How are leaves arranged on the body of different bryophyte gametophyes?
arrangement of the leaves is either radial or dorsiventral in mosses
Dorsiventral in liverorts and hornworts
How are the leaves arranged in different bryophyte gametophytes?
Spirally in mosses
In rows in liverworts
What is the difference between sporophyte elongation in different bryophytes?
sporophyte elongation is slow in mosses and fast in liverworts,
Hornworts are pseudoelaters which means Moisture-sensitive cells produced in the sporangium of hornworts
