Exam 3 Study Guide Flashcards
Understand the phylogenetic tree of the three Domains of life. How are they related to each other? (Where are the branches, what is closer related to what?)
3 Domains: Bacteria, Archaea, and Eukarya
Eukarya and Archaea are more closely related to each other
What Domain of prokaryotes are the extremophiles? What are the features that allows them to be tolerant of extreme conditions?
Archaea
- ether bonds in their membrane lipids
- isoprene chains instead of fatty acid chains
- protein cell wall instead of peptidoglycan
What are cyanobacteria? What makes them a special group of Bacteria?
cyanobacteria: photosynthetic and produce oxygen
- responsible for chloroplasts in eukaryotes
- responsible for eutrophication
- generate organic compounds
- high body diversity
Be able to explain what horizontal gene transfer is, and what it can be responsible for.
organism transfers genetic material to another organism that is not its offspring
- respond and adapt to their environment much more rapidly by acquiring large DNA sequences from another bacterium in a single transfer
Name the different types of organisms that use different energy and carbon sources for the six major modes of nutrition.
autotrophs: produce organic compounds from inorganic sources
- photoautotrophs: light source for energy, organic compounds from CO2, H2O, and H2S
- chemolithoautotrophs: energy from inorganic compounds
- chemoorganotrophs: oxidize sugar to make ATP and methane
Heterotrophs: require organic compounds from the environment
- photoheterotrophs: light energy to generate ATP
- chemolithoheterotrophs: energy from inorganic sources and absorb organic molecules for carbon source
-chemoheterotrophs: organic molecules for energy and carbon source
What organisms are responsible for plastids during endosymbiotic events?
land plants, green algae, and red algae
What is the difference between akinetes and endospores?
akinetes: dormant cells filled with food to survive harsh conditions
endospores: dormant cell that preserves genetic information
What type of reproduction do protists carry out?
asexual reproduction: based on mitotic cell division, daughter cell is genetically identical
sexual reproduction: based on meiotic cell division and fusion of gametes, daughter cells are genetically different from parents
What are the different types of endosymbiosis? What did this lead to?
- primary: heterotrophic cell captured cyanobacteria but did not digest (red/green algae)
- secondary: eukaryotic host cell ingest and retains a primary plastid
- tertiary: secondary plastic is engulfed by a heterotrophic eukaryote
Be able to annotate the asexual and sexual fungal life cycle with processes, phases, and ploidy level.
What are hyphae? And what is the term for a woven network of hyphae?
filament that makes up mycelia
- mycelia (mycelium)
Be able to compare and contrast the 2 major types of mycorrhizal fungi. What types of plants are each associated with, how they grow and exchange material with their host, etc.…
ecotmycorrhiza (EM): form partnerships with temperate forest trees and soil fungi; beech, oak, pine, and spruce trees
arbuscular mycorrhizae (AM): hyphae penetrates space between root cell wall and plasma membrane of plant roots; crops, shrubs, herbaceous plants, grasslands, and tropical forests
How do fungal hyphae grow?
by extending their tips through osmosis (cytoplasmic streaming)
What are plants most recent common ancestor?
green algae
What were the adaptations that allowed land plants to adapt to living on land?
- preventing water: production of cuticle, stoma, sporopollenin
- providing UV radiation protection: plant pigment (flaveroids)
- upright growth: to avoid falling, transport water, and nutrients (vascular tissue)
Understand the difference between a sporophyte and gametophyte forms of plants. Which one is haploid and which is diploid? What structure starts each phase?
sporophyte: multicellular diploid stage that produces haploid spores
gametophyte: multicellular haploid produces haploid gametes
What is meant by alternation of generations in terms of a plant’s life cycle? Be able to identify each generation when shown a plant life cycle. Which generations are dominant?
plants lifestyle alternates between a meiosis (haploid) phase that produces gametes and mitosis phase that produces spores
What is homosporous and heterosporous? And which plant groups show this type of life cycle.
heterosporous: megaspore (ovule/female) and microspore (pollen/male)
- seed plants
homosporous: one type of spore produced from one kind of sporangium
- nonvascular plants and most seedless vascular plants
What were adaptations of bryophytes to land?
- go from gametophyte dominant to sporophyte dominant
- develop vascular tissue + have a root system
- still produce spores
What is the pattern associated with gametophyte vs. sporophyte dominance as plants continued to evolve?
gametophyte dominant: gametes are motile and need water to reproduce, no vascular tissue, grow close to the ground
sporophyte: vascular tissue, respond better to environmental conditions, free-living, no longer dependent
What is the name of the vascular tissue that carries water? In what direction does it move?
xylem, moves water from the roots to the rest of the plant
What is the name of the vascular tissue that carries food (sugars and nutrients)? In what direction does it move?
phloem, bi-directional (upward and downward)
What is a seed and what is its evolutionary advantage?
allow for delayed germination until environmental conditions are favorable
- encloses embryos that contain carbohydrates, lipids, and proteins that enable embryo growth
Be able to explain the characteristics (and parts) of the ovule.
structure that develops into a seed
- integument: protective layer and prevent desiccation
- micropyle: small opening in integument where fertilization takes place
- ovule: megasporangium
