Supplemental Instruction
Iowa State University / Leader: / Andre
Course: / BIOL 211
Instructor: / Dr. Debinski, Dr. Heath
Date: / October 6
Fungi:
What are fungi, and how are they important to global ecosystems?
Decomposers – breaking down other organisms, absorbing nutrients
Saprophytes – digest plant material
Global Carbon Cycle – intake O2, release CO2
Animals are the closest relative of fungi
Two growth forms of fungi exist – unicellular yeasts, and filamentous, multicellular mycelia.
Explain the basic structure of mycelia and its features.
Mycelia – vegetative part of the fungus, high surface area to volume ratio – more efficient for water, nutrient absorption
Hyphae – long branching filaments composing the mycelia
Septa – cross-walls dividing the hyphae
Coenocytic– lacks septa
Spores – fundamental reproductive cell in fungi
Describe the differences between Basidiomycota, Ascomycota, and Zygomycota. Keep in mind the unique reproductive structures found on each. What is the fundamental reproductive cell in fungi?
Basidia– clusters of spores under the mushroom head
Asci – green bean with varying spores
Zygosporangia – airplane propeller looking thingy (fertilized spore)
Fungal relationships: Explain the difference between mycorrhizal relationships and endophytic relationships. What are lichens?
Mycorrhizal:symbiotic relationship between fungi and plants, underground (plant roots)
- Ectomycorrhizal:penetrates into the roots
- Arbuscular mycorrhizal:contacts, surrounds roots
Endophytic:above ground, between, on the leaves/stem
Lichens:relationship between a fungus and an algae/bacteria
Green Plants:
Which organisms are considered to be the green plants? How are these organisms similar and different?Both are photosynthetic.
Green Algae
-Protists, a lot less complex, aquatic environments
Land Plants
-Plants, a lot more complex, terrestrial environments
-Seedless Nonvascular Plants
-Seedless Vascular
-Seeded Vascular (Gymnosperms & Angiosperms)
How do the green plants affect our ecosystems?
Global Carbon Cycle
Remove CO2 from atmosphere, release O2
Carbon Sinks
Primary Producers – produce the most energy on terrestrial food chain
Artificial Selection – growing plants based on beneficial genetic traits
Describe these major events regarding land plant development, and provide the years in which they occurred.
700mya – First green algae: first fossils of the green algae, first evidence of photosynthesis
470mya – First land plants:first fossils of land plants. Developed a cuticle (waxy coating preventing dessication) and the stoma (pores for gas exchange)
400mya – Silurian-Devonian Explosion: first fossils recovered for all major plant lineages
350-300mya – Carboniferous Period: lots of coal recovered from the fossils of this period; indicate a very swampy environment, wetlands
300-150mya – Gymnosperm Diversification: gymnosperms start diversifying, gymnosperms start occupying dry regions
150mya – Angiosperm Diversification: angiosperms diversifying
Seedless Plants: Nonvascular and Vascular
Why was upright growth important as the land plants developed? Which organic material was significant to upward growth?
Grow taller to get more sunlight
Lignin – organic compound making up wood
As vascular tissue developed, specialized cells known as tracheids and vessel elements were established. How did they differ from traditional, simpler water conducing cells?
Tracheids – long, skinny, full 2nd layer of lignin, pores for gas exchange
Gymnosperms, Seedless Vascular
Vessel elements – short, stubby, full 2nd layer of lignin, and gaps for gas exchange
Angiosperms
The first plants faced a significant challenge in colonizing dry land – they needed a better form of gamete dispersal, and lacked motility (are sessile). What are the 3 important innovations that plants developed in order to better reproduce on dry land?
Dessication-resistant spores
Gametes produced in complex, multicellular structures – gametangia
Embryos are retained and nurtured by the parent plant
The seedless plants exhibit the basic life cycle involving alternation of generations. What does it mean to alternate generations? What does it mean to be a gametophyte or sporophyte? What are the types of gametangia?
Alt. of Gen. – switching between haploid (n) multicellular stage to diploid (2n) multicellular stage
Gametophyte – haploid stage
Sporophyte – diploid stage
Gametangia
Antheridium – sperm producing structure
Archegonium – egg producing structure
Draw or describe the life cycle of seedless plants to answer these questions. Furthermore, address the differences between the life cycle of seedless nonvascular and seedless vascular plants.
Sporophyte -> Spores -> Gametophytes -> Gametangia (Antheridia, Archegonia) -> Gametes (Sperm, Egg) -> Fertilization -> Zygote -> Sporophyte
Bryophytes are the lineage that exhibit a dominant gametophyte instead of a sporophyte.
Seeded Plants – Gymnosperms and Angiosperms
Seeded plants adapted new features that seedless plants lack. Explain these new features and their benefits.
Heterosporous:Produce 2 types of spores
Seeds:Protection, Nutrients, Transportation
Trends in the Life Cycle:Dominant sporophyte generation
What are the main differences between gymnosperms and angiosperms?
Angiosperms have…
Flowering plants
Double fertilization – 2nd sperm fuses with 2 nuclei to form triploid (3n) endosperm
Fruit
Like seedless plants, seeded plants exhibit a life cycle featuring alternation of generations. Draw or describe the life cycle of seeded plants, showing the differences between the angiosperms and gymnosperms.
What is adaptive radiation, and how does this relate to the angiosperm radiation? What major groups are angiosperms divided into, and why?
Single lineage has quick diversification into many descendant species
Monocot vs Dicot
Viruses:
What are characteristics of viruses? What are they composed of, and how do they replicate?
They are NOT prokaryotes, cellular, protists
NOT treatable with antibiotics
Composed of proteins and nucleic acids
Can be treated by vaccines
Can only replicated inside of cells of living organisms
Capsid – protein coat encompassing genetic material
Explain the following terms:
- Epidemic – spreads quickly, infecting a large population in a widening area
- Pandemic – epidemic that spreads worldwide
- Virulence– severity of the virus
- Virions– virus particles
Viruses that infect bacteria are known as bacteriophages.Briefly describe their process of replication.
Explain the two main ways that viruses leave their host cell.
- Bursting
- Budding
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