DAT bio chapter 9 Diversity of life Flashcards
taxonomy
science of classifying organisms
Mnemonic for memorizing taxonomy chart
King Phillip Came Over For Great Soup.
6 kingdoms are
Archaea, Eubacteria,
Protista, Fungi, Plantae, Animalia.
3 domains
Archaea, Bacteria (Eubacteria)
and Eukarya.
what is Archaea
are single-celled and tend
to be extremophiles (lives in extreme conditions and temp); they are prokaryotic.
What is bacteria
are also single-celled and prokaryotic.
What is eukarya
classified as having organelles and
membrane-bound nuclei.
What is a prokaryotes
organisms that do not have
membrane bound nuclei and tend to not have
membrane bound organelles.
Example of prokaryotes
Eubacteria and archaea
Difference between gram positives and gram negative
ONly in Bacterai (Eubacteria)
Gram positive bacteria have a thick peptidoglycan
layer in their cell wall, whereas gram negative
bacteria have a thin peptidoglycan layer and a
second outer membrane. Both are covered by a
capsule (a virulence factor protecting the
bacteria from drying out).
Characteristics of gram positive bacteria P1
-stain dark purple. ● thick peptidoglycan layer in cell wall. ● no outer membrane. ● very minor periplasm (outside plasma membrane).
Characteristics of gram positive bacteria P2
● No lipopolysaccharide (LPS - an endotoxin released when bacteria is destroyed). ● Secrete exotoxins. ● Contain teichoic acids (polysaccharide connecting peptidoglycan layer and plasma membrane for rigidity and structure).
Gram negative bacteria
● Stain pink (due to counterstain). ● Thin peptidoglycan layer in cell wall. ● Contains periplasm between inner and outer membranes. ● Outer membrane present. ● LPS present (in outer membrane). ● Secrete exotoxins. ● No teichoic acids.
Similarities between bacteria vs archaea
Contain cell walls. ● 70S ribosomes. ● DNA is organized in circular plasmids (horizontal gene transfer via pilli). ● Flagellum for movement. ● Reproduce via binary fission.
Difference between bacteria vs archaea
Eubacteria - Cell wall contains peptidoglycan; lipids bound via ester-linkage. -Ribosome has unique structure. -DNA lacks introns and histones.
Archaea - Cell wall lacks peptidoglycan; lipids bound via ether-linkage. -Ribosome has unique structure. -Contain introns, some have histones.
what is a eukaryote and give some examples
organisms whose cells contain
membrane-bound nuclei and organelles. E.g.
Protista, Fungi, Plantae, and Animalia.
What is a Protists
kingdom of (mostly unicellular) eukaryotic organisms.
what is a Fungus-like protists:
unlike fungi, no cell wall
made of chitin. Can move via cilia or flagella
(e.g. slime molds). Are saprophytic and feed
via phagocytosis. Reproduce via asexual
reproduction and sporulation (resist
environmental conditions).
Definition of saprophytic:
obtaining food by absorbing dissolved organic material especially : obtaining nourishment from the products of organic breakdown and decay
What is a Plant-like (algae-like) protists:
among the
most important primary producers.
3 types of plant-like protists
Diatoms, and euglenoids are unicellular,
photosynthetic autotrophs that reproduce
asexually and are found in aquatic
environments.
● Dinoflagellates: responsible for red tide
(toxins build up, O2
in water is depleted),
have two flagella (find food in absence of
light), and are heterotrophic (parasitic).
What is a Animal-like protists:
known as protozoa,
have food vacuoles. Include amoeba and
paramecium. Heterotrophic (move via flagella
and cilia) and are often parasitic pathogens.
What is a fungi
heterotrophic (move via flagella
and cilia) saprophytes.
2 types of fungi
nonfilamentous fungi and filamentous fungi
nonfilamentous fungi
(e.g. yeast) are
unicellular, reproduce asexually by budding, and
are facultative anaerobes.
Filamentous fungi
(e.g. molds) are
multicellular, multinucleate (form hyphae),
reproduce sexually, and are aerobic.
What is a hyphae
long, branching filaments that extend
out to form a network of fungi (mycelium).
Mycelium can either grow with septate hyphae
(have septa dividing hyphae into different
sections) or with coenocytic hyphae (one long
continuous multinucleated cell; cytokinesis does
not occur during cell division).
All the hyphae together is called ______
Mycelium
How do fungi reproduce in favorable conditions
reproduce
asexually by producing a haploid spore-producing
structure which produces haploid spores that grow
via mitosis.
How do fungi reproduce in unfavorable conditions
reproduce sexually-producing genetically different
offspring with greater chance of survival. Two
hyphae fuse their cytoplasm (plasmogamy) to
create a single fused cell with 2 haploid pronuclei
which fuse (karyogamy) to produce a single diploid
cell. The diploid cell produces a spore-producing
structure that produces spores via meiosis.
