exam 3 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?)
Bacteria, archaea, and eukarya
Archea and eukarya are the most related due to a common ancestor
What Domain of prokaryotes are the extremophiles? What are the features that allows them to be tolerant of extreme conditions?
extremophiles are Archea
Due to them having membrane lipids formed with ETHER bonds.
Ether bonds are resistant to damage by heat and extreme conditions.
What are cyanobacteria? What makes them a special group of Bacteria?
they photosynthesize and produce O2
allows for aerobic respiration and creates an ozone layer
Be able to explain what horizontal gene transfer is, and what it can be responsible for.
where an organism receives genetic material from another organism without being the offspring
to acquire new metabolic activities and diverse traits
Name the different types of organisms that use different energy and carbon sources for the six major modes of nutrition.
- Autotrophs
- Heterotrophs
Obligate aerobes ( require o2)
Obligate anaerobes ( poisoned o2)
Facultative aerobes ( verse)
Aerotoleratn anaerobes (ferm)
facultative anaerobes
What organisms are responsible for plastids during endosymbiotic events?
cyanobacteria were engulfed by ancestral eukaryotic cells, forming a symbiotic relationship that eventually led to the development of plastids within the host cells.
What is the difference between akinetes and endospores?
akin - large thick walled food filled whole
endo - dna and other materials become enclosed in a tough coating and reales when cell dies.
What type of reproduction do protists carry out?
both sexually and asexually depending on the environment.
What are the different types of endosymbiosis? What did this lead to?
Pri -eukaryotic host cell engulfs a free-living prokaryotic organism, forming a symbiotic relationship. The engulfed prokaryote then becomes an organelle within the host cell.
Sec - eukaryotic host cell engulfs another eukaryotic cell that already contains a primary endosymbiont. This results in the transfer of genetic material from the engulfed cell to the host cell, leading to the establishment of a new symbiotic relationship.
Ter - more and more diveristy
Be able to annotate the asexual and sexual fungal life cycle with processes, phases, and ploidy level.
Plasmogamy - fusion of haploid hyphae from compatible mating types, resulting in the formation of a dikaryotic cell.
Karyogamy - The nuclei of the dikaryotic cell fuse to form a diploid nucleus, completing the sexual cycle.
Meiosis - he diploid nucleus undergoes meiosis, producing haploid spores.
spore Dispersal- Haploid spores are released and dispersed into the environment.
What are hyphae? And what is the term for a woven network of hyphae?
basic structural units of fungi, consisting of long, thread-like filaments that make up the body of a fungus
“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.…
EM(ectomycorrhiza) -
associations primarily with woody plants, including trees such as pines, oaks, and birches,( temperate forests)
hyphae coat tree root surfaces and grow into spaces between tree root cells
AM(Arbuscular Mycorrhizae) -
associations primarily with herbaceous plants, including many agricultural crops such as grains, legumes, and vegetables
highly branched arbuscules for site of nutrient xchange.
How do fungal hyphae grow?
grow by extending tips through osmos
water enters hyphae because cytoplasm is rich in solutes.
swelling forces necessary extension
What are plants most recent common ancestor?
most recent common ancestor of plants is believed to be a freshwater green alga similar to modern charophytes.
What were the adaptations that allowed land plants to adapt to living on land?
- having a cuticle to prevent water from entering. a waxy watertight sealant
- providing uv radiation due to pigments like Flavonis
-up right growth due to vascular tissues
Understand the difference between a sporophyte and gametophyte forms of plants. Which one is haploid and which is diploid? What structure starts each phase?
sporo ( diploid ) 2n starts with zygote
gamete ( haploid ) n
starts with spore
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 b/w haploid stage that produces gametes and diploid which produces spores.
What is homosporous and heterosporous? And which plant groups show this type of life cycle.
homosporous plants produce a single type of spore and exhibit a gametophyte-dominant life cycle,
(ferns, mosses)
while heterosporous plants produce two distinct types of spores (microspores and megaspores) and exhibit a sporophyte-dominant life cycle.
(angiosperms, gymnosperms)
What were adaptations of bryophytes to land?
they had their cuticle, stomata, rhizoids, gametangia
What is the pattern associated with gametophyte vs. sporophyte dominance as plants continued to evolve?
reflects the evolutionary trajectory of land plant evolution, with an increasing emphasis on the sporophyte generation as plants adapted to a wide range of ecological niches and environmental challenges.
What is the name of the vascular tissue that carries water? In what direction does it move?
Xylem- provides support and carries water and minerals from roots to rest of plant
What is the name of the vascular tissue that carries food (sugars and nutrients)? In what direction does it move?
Phloem- composed of sieve tubes that conveys watery sap containing organic
molecules (sugar) through plan
parts of an ovule
integument- protective layer and prevents desiccation
micropyle - small opening in integument where fertilization takes place
ovule- megasporangiumm
What is a seed and what is its evolutionary advantage?
the endosperm, nutritive seed tissue that helps the seed or embyro grow
