TAMU BIO 112 EXAM 2- Eukaryotes and Fungi Sub-Advanced Preset Questions WITH 100% Verified Answers.

Eukaryote Organelles - correct answer -nucleus -cytoskeleton -food vacuole -contractile vacuole -plastids -chloroplast Nucleus - correct answer membrane bound, genetic material *micro/macro nuclei Cytoskeleton - correct answer -microtubules (largest) tubulin proteins *assemble and break apart quickly -microfilaments actin proteins *assemble and break apart quickly -intermediate filaments (smallest) *more permanent fibers Food Vacuole - correct answer small cavity in the cytoplasm of protists that temporarily stores food Contractile vacuole - correct answer The cell structure that collects extra water from the cytoplasm and then expels it from the cell Plastids - correct answer contain photosynthetic pigments Chloroplast - correct answer contains versions of chloroplast Microtubules are crucial is eukaryotes because... - correct answer -cell division -cell support endosymbiotic theory - correct answer -two prokaryotic lineages combined to create common ancestor of eukaryote *symbiogenesis engulfed cell---organelle *mitochondria *plastids -ingesting organic material -bacterium enters by endocytosis, but not digested -microtubules acquired here endosymbiotic theory evidence - correct answer -heterotrophic prokaryote and the mitochondria gained nucleus and ER from infolded plasma membrane -mitochondria gained from endosymbiosis of aerobic heterotrophic bacterium -eukaryote (w/mito.) gain chloroplast from endosymbiosis of cyanobacteria "serial endosymbiosis hypothesis" Protista - correct answer -complete organism -highly adaptable -require moisture -sessile or free swimming -presence of at least one motile stage in life cycle -no cell wall mutualistic relationship - correct answer both organisms benefit commensalistic relationship - correct answer one population benefits and one is unaffected parasitic relationship - correct answer A relationship that is one-way and detrimental to one of the organisms over time. plant-like protists - correct answer -autotrophic (synthesize own food from inorganic substances) animal-like protists - correct answer -heterotrophic (eat other organisms) *phagocytosis Pseudopodia - correct answer flowing cytoplasm Microfilaments (actin) and myosin motor protein also produce... - correct answer -cell movement ex: cytoplasmic streaming in plant cells cytoplasmic streaming: distributes nutrients throughout cell; can be seen in multicellular plants Photoautotrophs - correct answer -all w/chloroplasts w/chlorophyll 'A' -accessory pigments vary -some chloroplast:secondary endosymbiosis Chemoheterotrophs - correct answer ABSORPTIVE: monomers cross plasma membrane by diffusion/active transport *parasites and others may secrete digestive enzymes INGESTIVE: particles taken into cell by phagocytosis followed by intracellular digestion *food taken into digestive cavity, followed by extracellular digestion Eukaryotes (multicellular) kingdoms// overview - correct answer -Plants, Animals and Fungi *protists are all eukaryotes, aquatic or live in moist tissue. Multicellularity evolved several times.* Characteristics of fungi - correct answer -some multicellular and terrestrial -many Chytrids are aquatic -some are unicellular yeasts *live on water films, moist tissue The main fungus body is a... - correct answer mycelium Mycelium - correct answer -network of filamentous (thread-like) hyphae often unseen (underground or within hosts) -feed and grows; often enormous What makes up a hyphae? - correct answer -tubular cells w/rigid cell walls containing chitin(Rhizara-foraminifera super group). -cell membranes contain ergosterol, not cholesterol -septate (cross walls) or coenocytic hyphae (multi-nucleated cytoplasm) *both allow rapid cytoplasmic streaming Hyphae feeds by absorbing... - correct answer simple organic compounds Hyphae feeding functions - correct answer -fungus are ABSORPTIVE heterotrophs -most secrete hydrolytic enzymes and acids (this digest organic materials) -rapid growth at hyphal tips towards new food (no motile feeding cells) -huge total surface area for absorption specialized hyphae - correct answer -haustoria penetrate cell walls of host plants without killing the cell *host plasma membrane NOT penetrated -carnivorous fungi: wood decaying fungus Reproductive bodies emerge from a mycelium to make... - correct answer spores Fungal reproduction (spores) - correct answer -made in both sexual/asexual cycles *one cell (haploid), protected by coating *disperse by air/water to new resources -germinate on food source -each grows into a new haploid mycelium *spores made asexually at tips of hyphae* asexual reproduction in fungi - correct answer -fragmentation -budding -asexual spores by mitosis Fragmentation (asexual) - correct answer bits of mycelium can grow into a new individual Budding (asexual) - correct answer single cell yeasts--mitosis and asymmetric cytoplasmic division Asexual spores by mitosis - correct answer grow new genetically identical mycelia *growths like this are called "mold" Sexual cycles make... - correct answer no male/female gametes -no genders; instead: + or - mating types 3 steps to form a zygote - correct answer 1) Plasmogamy ("cytoplasmic marriage): fusion of haploid + & - hyphae 2) Heterokaryotic stage: hyphae with unfused haploid nuclei of both types 3) Karyogamy ("nuclear marriage"): fusion of + & - haploid nuclei to form zygote -zygote (2n) always does meiosis, making genetically diverse spores (n) -never a multicellular diploid (2n) stage Fungi Decomposers - correct answer -breakdown dead tissues (including lignin) -decomposing cellulose Fungi Mutualists - correct answer Mycorrhizae: -fungi living in close association with almost all plant roots -helps absorb moisture and minerals Ectomycorrhizae: -fungus remains outside root/between cells -fungi penetrate cell walls and form haustoria Fungus gets sugar from... - correct answer plants Lichens - correct answer -fungi living in close association w/photosynthetic unicellular chlorophyte/cyanobacteria -fungus "gives" framework, moisture, and minerals -algae and cyanobacteria give sugar -can reproduce as a "dual organism" Fungi Pathogens - correct answer -infecting many animals (chytrid fungi) and humans