Biodiversity Week 2 Part 2 Flashcards
where is most of the eukaryote diversity found in
among protists
what are bacteria and archaea considered
unicellular
what do all eukaryotes alive today have
- mitochondria or genes found in mitochondria
- nucleus and endomembrane system
- cytoskeleton
what are eukaryotic flagellum made up of
microtubules
- walk like motion
what are mitochondria
- organelles
- generate ATP using pyruvate as electron donor
- oxygen as electron acceptor
what is the endosymbiosis theory
proposes that mitochondria originated when a bacterial cell took up residence inside another cell
endosymbiosis
organism of one species lives inside cells of an organism of another species
secondary endosymbiosis
organism engulfs photosynthetic eukaryotic cell and retains chloroplasts
what did infoldings of the plasma membrane possibly given rise to
nuclear envelope and endoplasmic reticulum
why was the evolution of nuclear envelope advantageous
separated transcription and translation
what was the result of the mutation of organism containing more than one cell evolved
multicellularity
phagocytosis
uptake by a cell of small particles or cells by invagination and pinching of the plasma membrane to form small, membrane-bound vesicles
- eat other protists whole
what are the three ways protists can feed
- ingesting packets of food
- absorbing organic molecules directly from environment
- performing photosynthesis
ingestive lifestyles are based on what
eating live or dead organisms or on scavenging bits of organic debris
pseudopodia
- long, fingerlike projections
- ability to surround and swallow prey
when does absorptive feeding occur
nutrients are taken up directly from environment, across plasma membrane, through transport proteins
what are the types of absorptive feeders
- decomposers
- detritus
- parasite
decomposer
diet consist mainly of dead organic matter
detritus
layer of dead organic matter that accumulates at ground level or on seafloors and lake bottoms
parasite
absorptive species that damages its host
what direction do most protists move
in the direction to find food
amoeboid motion
sliding movement
- pseudopodia stream forward over a substrate
- motion requires ATP
flagella motion in protists
- flagella or cilia
- nine sets of paired microtubules
what is the difference between flagella and cilia
flagella are long and found alone or in pairs while cilia are short and occur in large numbers
what type of reproduction do most protists go through
asexual
- intersexual occurs only intermittently
difference between haploid and diploid
diploid have two of each type of chromosome while haploid have just one of each type of chromosome
what results in haploid cells
when meiosis occurs in diploid cells
what are the two main contrasts with haploid dominated life cycle
- meiosis occurs in mitotically produced offspring rather than zygote
- gametes are only haploid cells in diploid-dominated life cycle
alternation of generations
alternation of multicellular haploid stage with multicellular diploid stage
what is the multicellular haploid form
gametophyte
multicellular diploid form
sporophyte
spore
single haploid cell that divides mitotically to form multicellular haploid gametophyte
sporophytes produce what by what
produce spores by meiosis
gametophytes produce what by what
produce gametes by mitosis
