domains of life: plantae, Animalia, fungi, Protista, eubacteria
plantae: multicellular, eukaryotic
animalia: multicellular, eukaryotic
fungi: multicellular, eukaryotic
protista: eukaryotic, unicellular, and multicellular
eubacteria: unicellular, prokaryotic
domain definition
taxonomic classification above kingdom; largely determined by ribosomal DNA
prokaryotes vs eukaryotes
prokaryotes are unicellular organisms
- include bacteria
eukaryotes are multicellular organisms that have a true nucleus
- includes protists, fungi, plants, and animals
2 ways bacteria in the environment help us
- external: nitrogen fixation in soil
- internal: bacteria in our guts help with digestion
however, bacteria are often linked with pathogenesis– production of a diseased state
basic bacteria structures & functions:
- fimbriae
- cytoplasm
- ribosome
- plasmid
- flagellum
- pilus
fimbriae: sticky ends that help bacteria adhere to surfaces
cytoplasm: holds components of cell
ribosome: makes proteins
plasmid: DNA rings, carry genes for replicating DNA
flagellum: assist the cell in movement
pilus: conjugation or reproduction (sending antibiotic resistance and transferring genetic material)
protists
are eukaryotes because they have a nucleus and other membrane enclosed organelles even though they’re simple
- the well developed cytoskeleton of cell allows it to have asymmetric shape and to change shape as they feed, move, or grow (motility)
cilia vs flagellum vs pseudopods
cilia is a bunch of hair like things all over the body which make it swim forward
flagellum is one stick thing at the end that propels it forward
psuedopods are used for gliding, temporary arm-like projection that is emerged in the direction of movement
protozoa
animal like protists (eat other things)
- considered unicellular eukaryotes because of their enclosed nucleus
- heterotrophic and motile
algae
form of protists but are autotrophic, more specifically photosynthetic
(also eukaryotes)
fungi + classifications + reproduction + benefits/cons
form of multicellular eukaryotes
common classifications: mushrooms, yeasts, and molds
- can do BOTH sexual and asexual reproduction
benefits: decay of organic matter, food such as mushrooms, soy sauce, cheese, and yeast, and medicine (penicillin)
cons: fungal toxins (dont eat wild mushrooms, death cap mushroom), plant disease, human infections
- also heterotrophic (why they grow on food if left around for too long)
parts of a fungi: basidiocarp, hyphae, mycelium
basidiocarp: cap of mushroom, protects spore-producing surface
hyphae: long thin strands that tangle together to make up the mycelium
mycelium: main structure of a fungus (kinda at the roots part)
mushroom fungal life cycle
release of spores from underside of mushroom cap (spores are haploid) → spore lands on suitable surface and germinates (grows into hyphae) → grows into mycelium → two hyphae come together and fuse (sexual) → then it develops into mushroom (diploid) → releases spores and process recycles
nonvascular vs vascular plants
vascular - stand up on their own
nonvascular - can’t stand up on their own
main difference is their structure
yeast fungal life cycle
- single celled fungi
- reproduce asexually by budding or fission
- can also do sexually through conjugation when conditions are unfavorable for yeast
budding (asexual reproduction, haploid) → pseudohyphae formation → conjugation (sexual reproduction, diploid), usually called a/α→ meiosis and haploid spore formation
mold fungal lifecycle
- thrive in moist environments
- form hyphae branches
- spread via spores in the air
- think spoiled food
spore germination (asexual, haploid) → spores form hyphae → mitosis → reproduce asexually by producing structures called sporangia which produce haploid spores
otherwise: sexual reproduction (optional for them)
rhizoids: aid in attachment for reproductive structures, ex. sporangia or hyphae may develop at the tip of rhizoids, facilitating dispersal of spores
nonvascular plants (mosses & liverworts)
- gametophyte phase is dominant and haploid but rely on spores for reproduction
egg- producing structure = archegonia
sperm-producing structure = antheridia
resultant sporophyte (diploid) grows out of the archegonia
nonvascular seedless plants: mosses lifecycle
gametophyte is present in BOTH generations
mature gametophytes undergo mitosis to provide gametes → fertilization (diploid) via wind/rain → zygote matures into sporophyte that grows out of gametophyte → mature sporophytes bloom sporangium which is site of meiosis and produce haploid spores → spores released via wind, land and germinate into either male or female gametophytes
seedless vascular plants (club mosses and ferns)
sporophyte phase is dominant
- they have xylem and phloem - what gives them that vascular structure
- wind blown spores = no seed or flowers involved in plant reproduction
- unlike non-vascular plants, single gametophyte has BOTH sex structures
lifecycle of seeded plants
- two types: gymnosperms and angiosperms
- undergo generational alternation
- seeds are diploid (sporophyte) - produced for dispersal
female gametophyte is protected in the ovule (fruit)
male gametophyte is located in the pollen grains
spores = heterospores (production of spores of two different sizes and sexes - mega and microspore)
fertilized by pollination
gymnosperms vs angiosperms
gymnosperms: ovules and seeds are exposed to nature; pollen is transported via wind; often associated with cones (ugly like the gym guys)
angiosperms: seeds are enclosed in fruits (ovary); pollen transported via insects and animals; flowering plants (pretty like Angela)
gymnosperm lifecycle
- we focus on sub classification called conifers
dominant generation = sporophyte
pollen sacs and ovules are contained in cones; cones undergo meiosis to make microspores (male gametophyte) and megaspores (female gametophyte)
cones produced → pollination → fertilization (pollen grain makes pollen tube that grows toward the female gametophyte )→ diploid (egg develops into seed) → embryo has winged seed coat (for protection) → wind dispersal
angiosperm life cycle
- pollination occurs via insects
- flowers have within them the male structures called stamens that produce pollen grains containing male sperm and female structures called carpels which contains ovules
- pollinations occurs through insects or animals (haploid pollen microspore brought to megaspores)
- double fertilization: pollen tube reaches ovule and releases 2 sperm cells - one fertilizes egg and the other fuses with female gametophyte to become triploid (3n cell) that develops into endosperm which is like the food for the developing embryo
- fertilized diploid egg protected by ovary (fruit) grows
where are most of the earthworm’s structures?
coelom: body tube around the central digestive tract and also in the anterior region (close to the head)
earthworm reproductive anatomy
- reproductive structures at the anterior end (closer to head)
- hermaphrodites meaning both male and female reproductive organs
- can also reproduce asexually via regeneration
- male: seminal vesicles and seminal receptacles (visible during dissection, female hidden)
- female: female gonads
