lab 5: bacteria & autotrophic protists

Question 1

what is domain eukarya? the kingdoms in it?

Answer 1

-the third domain on the tree of life
-range from tiny single-celled species to sequoia trees & blue whales
-have membrane bound nucleus & organelles
-kingdom plantae, kingdom fungi, kingdom animalia, & protists

Question 2

what’s domain archaea? the kingdom?

Answer 2

-ancient life forms
-live in virtually every habitat, including extreme environments (extremophiles)
-similar to Earth, acidic, hot, salty, anaerobic, full of CO2 & H
-kingdom archae-bacteria

Question 3

what is domain bacteria? the kingdom?

Answer 3

-they are a monophyletic group (an ancestral population & all descendants)
distributed more widely than any other group of organisms
-microscopic
have cell walls that give them characteristic traits: bacillus (rod shaped), coccus (spherical shaped), spirillum (spiral shaped)
-kingdom bacteria

Question 4

what is the difference between bacteria & archaea?

Answer 4

-bacterias cell wall & membrane lipids are made up of fatty acids (peptidoglycan) while archaea is made of different chemicals (no peptidoglycan)
-many types of bacteria can photosynthesize & archaea can’t
-the flagella is different (archaea has little flagellum & bacteria has a lot)
-archaea reproduce by fission while bacteria produce spores
-the chemical makeup of their DNA & RNA is different
-some bacteria can cause disease (pathogenic) while archaea can’t (not pathogenic)

Question 5

what is the acronym “dear king Phillip came over for grape soda” stand for ?

Answer 5

domain , kingdom, phylum, class, order, family, genus, species

Question 6

autotrophs

Answer 6

manufacture their own food (carbon-containing compounds)
ex: plants with photosynthesis

Question 7

heterotrophs

Answer 7

-live by consuming other organisms
-most bacteria are this

Question 8

decomposers

Answer 8

feed on dead material & release nutrients not otherwise available to other organisms (locked up) = fungi

Question 9

parasites/parasitism

Answer 9

feed on living organisms & tissue

Question 10

asexual reproduction

Answer 10

-occurs via binary fission (cell pinches in half after DNA replication)
-offspring genetically identical to parents
-some bacteria: genetic recombination via conjugation (all or part of genetic material is transferred to another bacterium)

Question 11

extreme halophiles

Answer 11

-extreme salt lovers
-live in very salty conditions
-type of archaea

Question 12

methanogens

Answer 12

-methane makers
-type of archaea that produce methane & are killed by oxygen exposure
-found living in oxygen-free mud, at the bottom of the ocean, & inside digestive tracts of cows, termites & marine life

Question 13

hyperthermophiles

Answer 13

-type of archaea
-lives in environment that are hotter than 80°C
-such as waters of hot springs or geothermal pools

Question 14

bacillus (bacteria)

Answer 14

-rod shaped
-ex: firmicutes
-metabolically diverse
-species are important components of soil
-some species cause disease, others ferment milk into yogurt

Question 15

spirillum (bacteria)

Answer 15

-spiral shaped
-ex: spirochaeles (spirochetes) = corkscrew shape & unusual flagella
-very common in aquatic habitats
-cause disease: syphilis & lyme disease

Question 16

coccus (bacteria)

Answer 16

-ex: cyanobacteria formally known as “blue-green algae”
-photosynthetic bacteria
-reproduce by fission
-found as independent cells, chains, or colonies
-contain chlorophyll a & the accessory pigments to perform photosynthesis
-produce oxygen, nitrogen & organic compounds that feed other organisms in aquatic environments

Question 17

nitrogen cycle

Answer 17

N2 -> NH3 / NO3-
ex: rhizobium (provide ammonia to the plant while the plant provides sugars & other nutrients to the bacteria)

Question 18

mutualism

Answer 18

-both interacting organisms benefit
-ex: plant & rhizobium
-plant gets nitrogen in usable form & rhizobium needs a plant host to fix nitrogen & receives organic acids as carbon & energy source

Question 19

gram stain

Answer 19

-classify bacteria based on the stain & can tell their cell wall
-we can test antibiotics by knowing it because of the sensitivity of the bacterium

Question 20

bacterial sensitivity to inhibitors

Answer 20

-can tell which antibiotic can kill the bacteria
-can be able to circle the best/worst antibiotic based on the ring shows how effective it is

Question 21

cyanobacteria

Answer 21

-first organism that brought oxygen to environment; Earth’s atmosphere
-prokaryotes
-photosynthetic bacteria

Question 22

mitosis

Answer 22

-body cells
-occurs in all organisms (except viruses)
-one cell division
-no recombination/crossing over
-produces 2 diploid daughter cells
-daughter cells are identical

Question 23

meiosis

Answer 23

-follows same steps as mitosis
-occurs in animals, plants & fungi
-creates sex cells (gametes)
-two cell divisions
-recombination/crossing over that occurs in metaphase
-produces 4 haploid daughter cells
-daughter cells are genetically different

Question 24

protista/protists

Answer 24

-a diverse group of organisms that includes all eukaryotes except land plants, fungi & animals
-they live in moist habitats & include simple eukaryotes (like amoebas) as well as multicellular organisms (like brown algae-kelp)
-they don’t make up a well-defined monophyletic group due to differences in their DNA sequence & cellular features
-probably share a common ancestry with fungi, plants & animals
-common characteristics: most very small, tend to live in moist areas, diversity in immense
-can classify protists into several eukaryotic supergroups that display distinctive features

Question 25

algae

Answer 25

-importance: photosynthetic -> global oxygen production, base of food chain, key roles in ecosystem -algae applies to about 10 groups of protists that are predominantly photosynthetic -polyphyletic group (have more than 1 common ancestor) -major groups of algae are distinguished by their energy storage products, cell walls & color from pigments

Question 26

supergroup archaeplastida: green algae

Answer 26

-fresh & salt water -unicellular, filamentous, colonial -likely ancestral to land plants (share chlorophyll a & b, starch as carbohydrate storage material, cell walls of cellulose) -ex: spirogyra, cladophora, chlamydomonas -forms of green algae: unicellular (chlamydomonas), filamentous (spirogyra & cladophora), colonial (volvox)

Question 27

chlamydomonas (unicellular green algae)

Answer 27

-motile -soil, lakes, ditches -mostly asexual reproduction via mitosis -exception: unfavorable environment conditions: sexual reproduction -fusion of gametes -> diploid gametes -gametes = isogamous: identical shape & appearance (+ / -) -(+ / -) haploid gametes fuse to -> diploid zygote by syngamy -zygote surrounds itself with resistant surface called zygospore -under favorable conditions, the zygote undergoes meiosis to produce haploid individuals = spores -spores = reproductive cells capable of developing into an adult w/o fusing to another cell

Question 28

spirogyra (filamentous green algae)

Answer 28

-running streams, slippery -conjugation: sexual reproduction -fragmentation: asexual reproduction

Question 29

cladophora (filamentous green algae)

Answer 29

-common in streams -coarser appearance & texture -diploid stage = produce spores = sporophytes -haploid stage = produces gametes = gametophytes -reproductive system: haploid gametophytes -> gametes fuse -> zygotes -> diploid sporophyte -sporophyte: meiosis -> spores -> gametophytes

Question 30

volvox (colonial green algae)

Answer 30

-colonial -chlamydomonas = cells clustered in sphere -each cell has 2 flagella -some cells are specialized & can produce new colonies -reproduce by oogamy: motile sperm + large nonmotile = diploid zygote -zygote -> zygospore -> meiosis = haploid cells -haploid cells -> mitosis = start a new colony -volvocines- evolving multicellularity & colonial complexity

Question 31

supergroup archaeplastida: red algae

Answer 31

-live in warm marine habitats & can grow in many forms; live at considerable depths -consist mostly of multicellular species -almost all photosynthetic; a few are parasitic -no flagella -reproduce by producing spores through mitosis -obtain color from presence of red phycobilins in their plastids

Question 32

supergroup chromaveolata: brown algae

Answer 32

-primarily marine -complex, unique among protists, all species are multicellular -brown pigment: fucoxanthin -photosynthetic & sessile but reproductive cells may move -swimming gametes -> zygote = via sexual reproduction -species exhibit alternation of generations -form underwater forests & huge mats that are important habitats for wide variety of animals (kelp, sargassum) -economically important (food, alginic acid- use as emulsifier in processed foods & products)

Question 33

fucus in supergroup chromaveolata: brown-algae

Answer 33

-common rockweed -covered by a gelatinous sheath (to help keep moist, not dry out) -sexual reproduction: tips of branches = conceptacles contain the reproductive structures (oogonium: egg; antheridia: sperm) -eggs + sperm -> release to water -> mature thallus = diploid -cells within reproductive structures -> meiosis -> gametes -skip multicellular haploid stage (common to protists, plants, & fungi)

Question 34

supergroup chromalveolata: diatoms

Answer 34

-unicellular / form chains of cells -tiny -supported by external, silicon-rich, glassy shells (good fossils) -all species photosynthetic -primary link in food chain (numerous) -only sperm has flagella; adults either float in water or move via microtubules -can reproduce asexually or sexually -diatoms dominate the plankton of cold nutrient-rich waters -most important producer of carbon compounds in water

Question 35

supergroup chromalveolata: dinoflagellates

Answer 35

-unicellular -bizarre appearance of their cellulose plates & 2 flagella -primary producers -can be autotrophic or heterotrophic -bioluminescent

Question 36

harmful algal blooms

Answer 36

-occur when dinoflagellates, toxin-producing protists, reach high densities in an aquatic environment -algal blooms of dinoflagellates = red tides -can be harmful to humans because these toxins build up in clams & shellfish; if eaten person can become poisoned

Question 37

supergroup excavata: euglenoids

Answer 37

-unicellular flagellates -excavata: named for “excavated” feeding groove on 1 side of the cell -the 1000 known species of euglenoid mostly live in freshwater environments; others live in marine environments -mostly ingest bacteria / small cells (heterotrophic), although about 1/3 are photosynthetic (autotrophic) -some have light-sensitive eyespots called stigma & use flagella to swim to light -eyespot allow cells to sense light direction & intensity & respond to it by swimming