UF BSC2011 Douglas exam 1 |Questions and Answers
How is a phylogenetic tree different from a phylogeny? - -Tree: a hypothetical
reconstruction of a phylogeny, or the evolutionary relationships between species
-Phylogenetic lineage - -A series of ancestor-descendant relationships shown linearly with
respect to time
-Clade - -A common ancestor and all its descendants (can be at any taxonomic level)
-Sister lineage - -Would be included in a given clade if one more more recent ancestor was
included in said clade
-Synapomorphy - -A feature used to define a clade
-Homology - -A shared feature that hints at shared ancestry between two clades
-3 domains of life - -Eukarya, Archaea, Bacteria
-Chemical equation for photosynthesis - -Carbon dioxide + water + light ------> glucose +
oxygen
-2 main metabolic reactions of cyanobacteria - -Produce oxygen and pull N2 out of
atmosphere (nitrogen fixation -- needed to synthesize DNA/RNA and proteins)
-How did Earth's atmosphere become oxygen-rich, and what did oxygenation enable? - -
Photosynthetic organisms helped put O2 into the atmosphere, which enabled vascular life
to blossom (larger-scale life that metabolizes mainly aerobically)
Biggest increase in O2 concentration happened during Carboniferous: land plants
diversified and grew huge -- lots of photosynthesis
-Which of the following features shared by all mammals is likely to be a synapomorphy (a
shared characteristic derived in a recent ancestor)?
A. Milk production
B. Four limbs
C. Presence of a backbone
D. Breathing air - -Milk production: all mammals produce milk by definition
-Phylogenetic definition of "plants" - --Photosynthetic
-Contain chloroplasts derived from cyanobacterium primary endosymbiosis
ARCHAEA was the first domain to evolve chloroplasts!
, -Phylogeny of the primary plastids - --Red algae (glaucophytes)
-Standard green algae (chlorophytes)
-Other green algae (streptophytes)
-Land plants
First three clades are aquatic!
-Glaucophytes - -ancestral algae
-Synapomorphies of chlorophytes and streptophytes - --Chlorophyll a and b!
-Oogamy: different gametes between sexes
-Plasmodesmata: cell wall channels
-Parenchyma: 3D-cell stacking
-Branched apical growth -- could have evolved 2+ times
-Embryophytes - -Land plants that feature embryonic tissue; outgroup is
chlorophytes/streptophytes
-Function of mycorrhizae symbiosis - -This fungi fixes nutrients out of the soil and digests
hard things for plant roots, which feed the fungi sugars in turn
-Function of sporopollenin - -Protects and stabilizes spores in external environment
-Function of stomata and cuticle - -Stomata: allows for regulation of gas exchange with
(and water loss to) environment
Cuticle: waxy coating that protects external plant tissues and slows water loss
-Primary endosymbiosis - -Engulfment of photosynthetic cyanobacterium in algae,
spawning photosynthetic abilities in all land plants
This is why the chloroplast genome is circular!
-Secondary endosymbiosis - -Engulfment of a eukaryote whose ancestor cell participated
in primary endosymbiosis
-Plants are photosynthetic ______-karyotes whose common ancestor captured a
photosynthetic partner that was _____-karyotic; i.e. a ____________________ - -eukaryotes;
prokaryotes; cyanobacterium
-Is "green algae" a clade? - -No -- streptophytes and chlorophytes are clades that both
partially contain green algal organisms
-Function of starch vs. simpler carbohydrates - -Starch is a complex carb that can store
chemical energy in a denser form than mono-, di-, or certain other poly-saccharides
, -2 clades of land plants - -Bryophytes (hornworts, mosses, liverworts -- hepatophytes) and
tracheophytes (vascular plants)
-Characteristics of bryophytes - --Small size
-Lack true roots, stems, and leaves
-Get water by osmosis through rhizoids (hyphae that grow down into the substrate, soil)
-Swimming (motile) sperm that require water
-Relatively hardy -- some can survive in xeric conditions
-Gametangia - -A reproductive organ that houses and protects the gametes of a plant
Archegonia: female (egg)
Antheridia: male (sperm)
-Sporangia - -In bryophytes, stem off of a gametophyte into a dependent structure that
undergoes mitosis rapidly to elongate
-Diploid and relatively small
-Alternation of generations: nonvascular vs. vascular plants - -Gametophyte (haploid) life
cycle is dominant in nonvascular plants; sporophyte (diploid) life cycle is dominant in
vascular plants
-What benefits arose from aquatic plants colonizing land? - --More room to grow
-After root systems developed, nutrients could be accessed easily
-Fossil record dates land plants back to 460+ mya
-Characteristic features of liverworts - --Green and flat with apical growth
-Can reproduce asexually with gemmae cups
-Constitute hepatophyte clade
-Leaflike lobes (not true leaves)
-Characteristics of bryophyte mosses - --Erect and leafy
-Feature stomata and hydroids (precursors to tracheids that allow water to passively
move)
-Peristome teeth on sporophyte that aids in spore dispersal -- hygroscopic (change shape
with humidity)
-Characteristics of hornworts - --Only about 100 extant species
-Sporophyte generations look horned
-Sporophyte grows from a basal region capable of infinite cell division
-Symbiotic with cyanobacteria that fix N2 inside hornwort internal cavities
-An ecologically/economically important bryophyte - -sphagnum (pearmoss) genus:
secretes tannins that helps bury a lot of CO2 in the atmosphere -- this is how coal is formed
How is a phylogenetic tree different from a phylogeny? - -Tree: a hypothetical
reconstruction of a phylogeny, or the evolutionary relationships between species
-Phylogenetic lineage - -A series of ancestor-descendant relationships shown linearly with
respect to time
-Clade - -A common ancestor and all its descendants (can be at any taxonomic level)
-Sister lineage - -Would be included in a given clade if one more more recent ancestor was
included in said clade
-Synapomorphy - -A feature used to define a clade
-Homology - -A shared feature that hints at shared ancestry between two clades
-3 domains of life - -Eukarya, Archaea, Bacteria
-Chemical equation for photosynthesis - -Carbon dioxide + water + light ------> glucose +
oxygen
-2 main metabolic reactions of cyanobacteria - -Produce oxygen and pull N2 out of
atmosphere (nitrogen fixation -- needed to synthesize DNA/RNA and proteins)
-How did Earth's atmosphere become oxygen-rich, and what did oxygenation enable? - -
Photosynthetic organisms helped put O2 into the atmosphere, which enabled vascular life
to blossom (larger-scale life that metabolizes mainly aerobically)
Biggest increase in O2 concentration happened during Carboniferous: land plants
diversified and grew huge -- lots of photosynthesis
-Which of the following features shared by all mammals is likely to be a synapomorphy (a
shared characteristic derived in a recent ancestor)?
A. Milk production
B. Four limbs
C. Presence of a backbone
D. Breathing air - -Milk production: all mammals produce milk by definition
-Phylogenetic definition of "plants" - --Photosynthetic
-Contain chloroplasts derived from cyanobacterium primary endosymbiosis
ARCHAEA was the first domain to evolve chloroplasts!
, -Phylogeny of the primary plastids - --Red algae (glaucophytes)
-Standard green algae (chlorophytes)
-Other green algae (streptophytes)
-Land plants
First three clades are aquatic!
-Glaucophytes - -ancestral algae
-Synapomorphies of chlorophytes and streptophytes - --Chlorophyll a and b!
-Oogamy: different gametes between sexes
-Plasmodesmata: cell wall channels
-Parenchyma: 3D-cell stacking
-Branched apical growth -- could have evolved 2+ times
-Embryophytes - -Land plants that feature embryonic tissue; outgroup is
chlorophytes/streptophytes
-Function of mycorrhizae symbiosis - -This fungi fixes nutrients out of the soil and digests
hard things for plant roots, which feed the fungi sugars in turn
-Function of sporopollenin - -Protects and stabilizes spores in external environment
-Function of stomata and cuticle - -Stomata: allows for regulation of gas exchange with
(and water loss to) environment
Cuticle: waxy coating that protects external plant tissues and slows water loss
-Primary endosymbiosis - -Engulfment of photosynthetic cyanobacterium in algae,
spawning photosynthetic abilities in all land plants
This is why the chloroplast genome is circular!
-Secondary endosymbiosis - -Engulfment of a eukaryote whose ancestor cell participated
in primary endosymbiosis
-Plants are photosynthetic ______-karyotes whose common ancestor captured a
photosynthetic partner that was _____-karyotic; i.e. a ____________________ - -eukaryotes;
prokaryotes; cyanobacterium
-Is "green algae" a clade? - -No -- streptophytes and chlorophytes are clades that both
partially contain green algal organisms
-Function of starch vs. simpler carbohydrates - -Starch is a complex carb that can store
chemical energy in a denser form than mono-, di-, or certain other poly-saccharides
, -2 clades of land plants - -Bryophytes (hornworts, mosses, liverworts -- hepatophytes) and
tracheophytes (vascular plants)
-Characteristics of bryophytes - --Small size
-Lack true roots, stems, and leaves
-Get water by osmosis through rhizoids (hyphae that grow down into the substrate, soil)
-Swimming (motile) sperm that require water
-Relatively hardy -- some can survive in xeric conditions
-Gametangia - -A reproductive organ that houses and protects the gametes of a plant
Archegonia: female (egg)
Antheridia: male (sperm)
-Sporangia - -In bryophytes, stem off of a gametophyte into a dependent structure that
undergoes mitosis rapidly to elongate
-Diploid and relatively small
-Alternation of generations: nonvascular vs. vascular plants - -Gametophyte (haploid) life
cycle is dominant in nonvascular plants; sporophyte (diploid) life cycle is dominant in
vascular plants
-What benefits arose from aquatic plants colonizing land? - --More room to grow
-After root systems developed, nutrients could be accessed easily
-Fossil record dates land plants back to 460+ mya
-Characteristic features of liverworts - --Green and flat with apical growth
-Can reproduce asexually with gemmae cups
-Constitute hepatophyte clade
-Leaflike lobes (not true leaves)
-Characteristics of bryophyte mosses - --Erect and leafy
-Feature stomata and hydroids (precursors to tracheids that allow water to passively
move)
-Peristome teeth on sporophyte that aids in spore dispersal -- hygroscopic (change shape
with humidity)
-Characteristics of hornworts - --Only about 100 extant species
-Sporophyte generations look horned
-Sporophyte grows from a basal region capable of infinite cell division
-Symbiotic with cyanobacteria that fix N2 inside hornwort internal cavities
-An ecologically/economically important bryophyte - -sphagnum (pearmoss) genus:
secretes tannins that helps bury a lot of CO2 in the atmosphere -- this is how coal is formed
