Lecture 18 Flashcards
Flower structure!
explain:
- carpel
- stamen
- 4 other parts
CARPEL
- stigma
- style
- ovary
- ovule
STAMEN
- anther
- filamen
PETALS = corolla
SEPAL = calyx
RECEPTACLE
PREDUNCLE
explain carrion flowers
- smells like rotting flesh to attract carrion flies
explain hummingbird-pollinated flowers
- red, long tubes with nectar at the base
explain bee-pollinated flowers
- often bright purple
explain the double fertilization only in ____
- only in angiosperms
- pollen grain is reduced to only 2 cells when dispersed and finally has 3 cells: a tube nucleus, and 2 sperm nuclei
- one fuses with egg nucleus to form a sporophyte zygote and the other with 2 nuclei in the ovule to produce the 3n endosperm nutritive tissue (sperm + 2 haploid female nuclei_
- only 8 cells in female gametophyte; 1 is the egg
what are the 5 main differences between dicots and monocots
DICOTS
- 2 cotyledons
- vascular tissue in circular arrangement in stem
- branching veins in leaves
- petals in multiples of 4 or 5
- pollen has 3 or more apertures (pores or slits) in the pollen wall, thing spots where the pollen tube can emerge
MONOCOTS
- 1 cotyledon
- vascular tissue scattered throughout stem
- parallel veins in leaves (bundles of vascular tissue)
- petals in multiples of 3
- pollen with single aperture
ex. palms, orchids, lilies, grasses
review some local medicinal plants
Pacific yew trees (Taxus brevifolia)
- produces taxol in bark, used for treating ovarian cancer
Cascara (Rhamnus purshiana)
- bark was used to make the laxatative called cascara sagrada
Foxglove (Digitalis purpurea)
- weedy roadside herb introduced from Europe to treat weak hearts from its medicinal biochemical (digitalin) and many others
What is the first fungi found in the ordovician period
- mycorrhizae
explain fungi and plants: mycorrhizae
mycorrhizal fungi and plants form mutualisms
- plant roots obtain nutrients and water from the fungi
- fungi obtain organic carbon from the plants
- fungal mycelium = network made up of hyphae (individual fungal filaments)
What are fungis?
- eukaryotes
- chemoheterotrophs: absorb food externally after chemical digestion. obtain energy by digesting organic materials (like animals), but not ingest like animals
- most are decomposers (saprophytic
- symbiotic (lichens, mycorrhizae)
- parasitic or predatory
predatory fungi: (1)form trapping structures; (2) endoparasites that infect nematodes as spores whose saprotrophic phase is predominantly within the nematode body; and (3) parasites of cyst nematodes that almost exclusively infect the females, eggs or larvae
give some exampels
- foot fungus
- nematode-snaring fungus
- ant parasitized by a fungus that controls death behaviour of the ant
give examples of parasitic fungi
economic impacts of fungi:
- food spoilage and crop reductions
- corn smut
- wheat rust
- bread mold
whats some examples of “useful” fungi
- yeasts (unicellular fungi in baking and brewing of alcoholic beverages: both convert sugars and starch into Co2 and alcohol
explain the life cycle of fungi
hyphae from 2 diff individuals fuse their cytoplasm to form cells with 2 diff nuclei: dikaryotic: 2 nuclei cna later fuse to make a 2n zygote, then undergo meiosis to produce spores and new mycelia
SEXUAL
spores - mitosis - mycelium - plasmogamy - heterokaryotic mycelium - karyogamy - zygote - meiosis - spore-producing structure - spore
ASEXUAL
spores - mitosis - mycelium - mitosis - spore-producing structure - mitosis - spores
What is plasmogamy
- fusion of cytoplasm from different individuals (2 hyphaes)
