1. Supplemental Instruction 2/20/2018
BIOL 211 Exam 3 review
Supplemental Instruction
2/20/2018

2. Origin of Land Plants ANSWER:
Match these events with their appropriate times…
Cyanobacteria
Land plants
First small plants
Lifeless terrestrial environment
1st 3 billion years
500 MYA
1.2 BYA
370 MYA
ANSWER:
1st 3 billion yrs: lifeless terrestrial environment
1.2 BYA: cyanobacteria
500 MYA: first small plants
370 MYA: land plants

3. Origin of Land Plants Land plants are related to protists.
Alteration of generations is exhibited in which group?
Brown algae
Red algae
Green algae
A: Brown algae

4. 3 main characteristics shared between most plants and protists:
1. Multicellular, photosynthetic autotrophs
2. Cellulose cell walls
3. Chloroplasts with chlorophylls a and b
So.. We know plants began as aquatic algae.. Why move to a terrestrial environment?
1. More exposure to sunlight
2. Atmosphere with abundant CO2
3. Few herbivores and pathogens (at first)
4. Minerals in soil
What specific type of green algae is believed to be the closest relative to land plants?
Charophyceans

5. Characteristics separating plants from Charophyceans
Apical meristems
- plant’s stem cells that differentiate into various tissues
Alteration of generations
- gametophyte (n) produce gametes by mitosis; sporophyte (2n) produce spores (n) by meiosis
Walled spores produced in sporangia
- plant sporophyte has a multicellular sporangium that produces spores
Multicellular gametangia
- plants produce gametes within gametangia – F:archegonia M: antheridia; egg is fertilized in archegonia
Multicellular, dependent embryos
- plant embryos develop from zygotes that are retained in the tissues of female; female provides embryo with nutrients

6. Plants have a cuticle to prevent water loss while charophyceans (green algae) do not.
How are plants grouped? By their vascular and reproductive structures.
Groups include:
Nonvascular – bryophytes
Seedless vascular – ferns
Gymnosperms (vascular, naked seeds) – conifers
Angiosperms (vascular, covered seeds) – flowers

7. Nonvascular Bryophytes Phylums: Anthocerophyta (hornworts)
Hepatophyta (liverworts)
Bryophyta (mosses)
Life cycle includes alteration of generations (like all plants)
Gametophyte is the dominant stage - reduced sporophyte
*require water for reproduction – sperm must have water to swim to egg in the archegonia – sperm are flagellated

8. Seedless Vascular Plants
Life cycle with dominant sporophyte
Vascular tissues – xylem and phloem
Roots and leaves
Two phyla:
Lycophyta (lycopods, club mosses)
Pterophyta (ferns, whisk ferns, horsetails)
Sporangia produce spores on the sporophyte plant
*Gametophyte reduced in ferns – trend in plant evolution

9. 5 Characteristics of all seed plants
Production of seeds
Reduced gametophyte
Heterospory – 2 types of spores
Ovules
Pollen
What is a seed?
Formed after fertilization of an egg by a sperm; the embryo.

10. Gymnosperms 4 phyla: Cycadophyta - palm trees
Ginkgophyta - only one species: Ginkgo biloba
Gnetophyta - not sure what these are
Coniferophyta – conifers (pines, firs, cypress, cedars) “evergreen”
Which of the following are amongst the oldest and largest organisms on earth?
Palm trees
Ginkgo
Conifers
C. Conifers

11. Angiosperms Monocots vs dicots – 1 cotyledon vs 2
Characteristics: Flowers, fruits, double fertilization
Flowers increase success of pollination
Fruits cover seeds to aid in dispersal
Double fertilization – formation of zygote and endosperm
Seed = mature ovule
Fruit = mature ovary
Both angiosperms and gymnosperms have ovules but gymnosperms are exposed to environment

12. Double fertilization Only occurs in angiosperms
One sperm nucleus + egg = zygote (2n)
One sperm nucleus + 2 polar bodies
= endosperm (3n)

13. Parts of a Flower

14. Fungi The world’s largest organism - Fungi are not plants
Eukaryotic heterotrophs that obtain food by absorption.
Share a common ancestor with animals.
Decomposers, parasites, or mutualistic symbionts.
Unicellular or multicellular
Composed of filaments (hyphae) – hyphae make up mycelium – hyphae can be divided by septa
Cell walls are made of chitin
Feeding network of fungus - mycelium
Fruiting body produces spores
Can reproduce either asexually or sexually – when hyphae meet it is called plasmogamy