Bio 112 Final
In what form are macro- and micronutrients taken up by plants?
as ions dissolved in the water of the soil plants take up water, the ions come with it
Batesian mimicry vs. Müllerian mimicry
as seen in Monarch and Viceroy butterflies Batesian mimicry: harmless species mimics noxious species in appearance (harmless species benefits, noxious species fairly unaffected) Müllerian mimicry: both species are noxious, both benefitting by having the same warning colors It's now thought that Monarch and Viceroy butterflies use Müllerian mimicry.
Examples of Cestodes (tapeworms)
Taenia saginata (beef tapeworm) Taenia solium (pork tapeworm) Echinococcus granulosus (dog tapeworm)
Why is a cestode not considered metameric?
Tapeworms have segments, but those segments don't work as a functioning whole.
population ecology
assemblage of all individuals of one species that live in the same location and are physically separated from other populations of that species
types of symmetry in animals
asymmetrical, radial, bilateral
How do leeches suck blood?
attaches to host, creates seal with suction, makes small incision to access host blood
phytoplankton
autotrophic plankton: protists and bacteria
evolution
change in frequency (%) of traits in a population over time
Archosaurs: -What synapomorphy characterizes them? -What lineages are within the Archosaurs?
characterized by thecodont teeth Crocodilians, Pterosaurs, Dinosaurs
convergence (homoplasy)
characters in two organisms resemble each other but have each been derived independently (for example because they have adapted to similar functions)—not because they share a common ancestor that had this character.
Where in the cell do photosynthesis and cellular respiration occur?
chloroplasts and mitochondria, respectively
What phylum do humans belong to?
chordates
Eumetozoa What's the one animal phylum that's not part of Eumetozoa?
clade of animals with cells organized into true tissue (germ) layers all animals except sponges (Porifera)
Therians
clade of mammals including marsupials and eutherians
major influences on plant life/vegetation type? (ie what environmental factors define biomes?)
climate, especially temperature and rainfall latitude and altitude: equator has little/no seasonality, seasonality increases as you get farther north/south of equator. Higher altitude means colder temperature In favorable environments, plant growth is greater and vegetation is more complex: 1. denser 2. more layered 3. greater cover (covers more ground) 4. typically more species-rich --> more niches for consumers In resource-limiting environments (water, temperature): 1. less plant growth, more bare ground 2. low-growing plants 3. not many consumer niches, plus weather is more limiting to consumer survival
Why are amniotes so important? What advantages do they have for terrestrial living?
completed the transition to land that amphibians started amnion = membrane to protect embryo from water loss keratinized epidermis - scales (feathers, hair) reduce water loss through skin
paraphyletic group
composed of some but not all members descending from a common ancestor (a group that's not a clade)
What is concertina swallowing?
compression/extension of predator's vertebrae slides predator snake over prey
landscape ecology
connections between ecosystems, movement of elements (living and nonliving) between ecosystems
Why is Archaeopteryx such an important fossil?
considered a "missing link" fossil: resembles modern birds -feathers (flight) -wings resemble that of a bird resembles its reptile ancestors -teeth -claws on wings -tail is lizard-like, as opposed to a bird tail that's made only of feathers
Brown recluse spider venom
contains enzymes that digest prey
thecodont teeth
continuously-replacing teeth held in sockets (think crocodile teeth)
Cephalopoda eye vs. vertebrate eye
convergent evolution inverted retina = vertebrate eye, verted retina = cephalopod eye Cephalopod eye: nerves attached underneath retina cells --> no need for a blind spot where optic nerve leaves the back of the eye --> Cephalopod eyes are more efficient than ours
What characterizes the habitat of Sphagnum moss?
cool and wet environments cool --> slow decomposition of organic matter wet --> CO2 dissolves well in water, O2 doesn't CO2 + H2O --> H2CO3 --> H+ + HCO3- (carbonic acid) peat = dead sphagnum moss --> fuel (carbon reserves that don't break down)
examples of parasitic Basidiomycota
corn smut, rust fungi (I have separate flashcards for each of these)
Why is Class Myxini called a "slime hag?"
defense mechanism: produces a lot of slime in a short timeframe (from its slime glands) --> gums up gills of predators
type specimens
designated as a representative of the species (for museum study)
Are we protostomes or deuterostomes?
deuterostomes
character mapping
placing certain characters of organism(s) on a phylogenetic tree. eg looking at where on the tree multicellularity arose and marking it all the markings like "vertebrae" and "hair" on this phylogenetic tree represent character mapping
Arthropods: exoskeleton (what is it and what material is it made of?)
hard outer cuticle made of chitin (arthropods have no internal skeleton)
What is the basis for describing biomes?
plant life (vegetation = plant life and appearance of plants)
node of phylogenetic tree
represents the last common ancestor shared by organisms above this point on tree
paedomorphosis
retention of juvenile/larval characters in adult
Which of the 4 main clades of eutherians has the most species? Which is the most diverse?
The Euarchontoglires have the most species. The Laurasiatheres are the most diverse.
What defines the imperfect fungi? Why are they called "molds"?
-"imperfect fungi:" fungi for which no sexual reproduction is known (seem to be members of Ascomycota and Basidiomycota, based in part on the morphology of the asexual sporangia) -"molds" - they only reproduce asexually, so they always look like molds
characteristics of fungal cells? fungal cell wall chemistry?
The cell is like a plant cell without chloroplasts. Cells also have vacuoles that can take up/lose water to maintain pressure against cell wall. The cell wall has chitin (nitrogen-containing polysaccharide). There's a large pore in the cell wall for cell-cell transport.
things to keep in mind when looking at phylogenetic trees?
What direction represents the progression of time? What assumptions are the authors making? (eg many historical phylogenetic trees are influenced by religion, automatically place humans as "most important" or "most complex," etc.)
"Insect apocalypse:" -What is it? -Why should we worry? -What can we do about it?
What is it? -huge decrease in numbers of insects (from study of Puerto Rican rainforest that's thought to be generalizable to the whole world) Why should we worry? -insects = primary consumers (2nd level of trophic pyramid) -fewer insects --> less food for upper levels of pyramid (including us) What can we do about it? -use fewer pesticides in agriculture (#1 contributor to decline) -less urbanization, deforestation, climate change
variation within alternation of generations
heteromorphic (bodies of two phases look different) vs. isomorphic (bodies of two phases look identical) larger and longer-lived phase = dominant
zooplankton
heterotrophic plankton: protists and animals Zooplankton eat phytoplankton.
fungi mode of feeding
heterotrophic with external digestion followed by absorption saprobic and parasitic: many produce toxins
Amniota
higher vertebrates (reptiles, birds and mammals) possessing an amnion during development ie animals vertebrates with amniotic eggs
Hirudo medicinalis ("the medicinal leech") historical uses? modern uses?
historial uses (1700s): doctors thought that bleeding patients would remove bad humor --> kill illness modern uses: plastic surgery. When reattaching a detached body part eg an ear, attach leeches. The leeches secrete anticoagulants which help small blood vessels heal.
intermediate host
host in which parasite develops but doesn't reproduce
definitive host
host in which parasite reproduces
How are ferns & allies related to our major sources of coal?
huge forests of ferns during Carboniferous period, which is the period which produced a large proportion of the coal we have today
Schistosomiasis: life cycle (definitive and intermediate hosts?)
humans = definitive host, snails = intermediate host. cercariae = larvae
examples of homology
hummingbird and ostrich wings
How do the ferns increase the likelihood that their spores will be transported in the air?
hygroscopic tissues in annulus of sporangium
What adaptations do mosses show to ensure that their spores can be transported in the air? (ie how do hygroscopic tissues work?)
hygroscopic tissues of peristome: sensitive to air humidity --> take up/lose water --> release spores when the humidity is low (windy weather) ADD MORE?
How do ferns & allies disperse to new sites?
hygroscopic tissues releasing spores
Bryophytes: in what structures are the sperm and egg produced, and how does fertilization occur?
in gametangia on gametophytes. Fertilization occurs when water levels are high enough for sperm to swim to an egg. The zygote grows into the sporophyte within the female gametangium.
ferns & allies: in what structures are spores produced? Are spores haploid or diploid (or both)?
in sporangium, which is part of the sorus, which is on the leaf of the sporophyte. Spores are haploid.
voucher specimens
individual of a species you bring back from field study to represent findings ("vouching" for the species)
Examples of insect pollination and bird pollination? (lab & video)
insect pollination: bees bird pollination: hummingbirds ADD MORE DETAIL
Give two examples of common deuteromycetes, describing their sporangial structure (lab)
penicillium (looks like a shrub), aspergillus (looks like a pinhead)
synapomorphies for deuterostomes
pharyngeal slits, deuterostomy
What groups of organisms carry out photosynthesis? Are they mainly terrestrial, aquatic, or both?
photoautotrophs (plants, cyanobacteria, and plant-like protists, ie algae). They're both terrestrial and aquatic.
How and why did earth's atmosphere change over time in its oxygen content?
photosynthetic prokaryotes (cyanobacteria) caused increase in atmospheric O2
oxygen revolution
photosynthetic prokaryotes --> O2 in atmosphere --> many prokaryotes not able to process O2 went extinct --> evolution of cellular respiration 2.7 billion years ago
What is phylogeny? What's at the basis of our classifications of organisms?
phylogeny = evolutionary aspect of species. Living organisms are classified into hierarchical groups based on evolutionary relationships.
main two processes involved in the origin of eukaryotic cells
pinching-off of membrane infoldings: allowed for single-membrane organelles like endoplasmic reticulum (not much lab evidence for this) primary endosymbiosis: a larger cell engulfed an aerobic heterotrophic prokaryote --> mutualism (evidence: mitochondria and chloroplasts similar to prokaryotes in terms of size, circular DNA, ribosome composition, binary fission) all eukaryotes have mitochondria, only some have chloroplasts --> mitochondria must've arose first
Clade Afrotheria: etymology and biogeography
-"Afrotheres" because the clade first evolved in Africa when it was separate from the other continents -now, some groups have diversified beyond Africa
Anura (frogs and toads) -etymology of name -number of species -morphological diversity -other characteristics
-"Anura" = "without a tail" -5,250 species!! -enormous number of species, but highly derived (similar) morphology: no tail, big hind legs for swimming/jumping, large eyes -variety of reproductive strategies (see the other slide on this)
Clade Laurasiatheria: etymology and biogeography What's special about the diversity of this clade?
-"Laurasiatheres" is a reference to Laurasia, the large northern continent that existed after Pangaea broke up. Laurasia was the center of Laurasiatheres' diversification. -most diverse clade of eutherians: includes everything from marine to flying mammals
Clade Xenarthra: etymology and biogeography
-"Xenarthrans" describes the distinctive way their vertebrae are joined -South American origin
Sponges: amoebocytes
-"amoebo-" because they move like and are shaped like amoebas -deliver food to different parts of the sponge and make eggs -collars of choanocytes collect food and pass it to amoebocytes
sponges: choanocytes
-"collar cells" -line water channels within sponge and help drive water current via flagella -can also make sperm -collars of choanocytes collect food and pass it to ameobocytes -look like badminton birdies :)
Echinoidea (sea urchins and sand dollars) characteristics -etymology of name -distinguishing morphological characteristics
-"echino" = "spiny" (spiniest Echinoderms) -roughly spherical or disk-shaped -no arms -5 rows of tube feet - they can move slowly -spines, which may contain venom! -pedicellariae: jaws on long stalks on external surface of sea urchin *clean body *catch food *may contain venom sacs - defense
equation for cellular respiration
C6H12O6 + 6O2 --> 6CO2 + 6H2O + ATP + heat
atmospheric composition of early earth
CH4, CO2, CO H2, H2O NH3, N2 H2S, SO2 no free O2
examples of parasitic Ascomycota
Dutch Elm Disease, Ergot, Mycoses (I have a flashcard for each of these) There are also pathogens that infect insects; sexual bodies grow out of insect carcasses and look super creepy
lamprey feeding mechanism
Feeds on blood (parasite). Attaches to the host with its mouth (teeth and suction). Uses tongue to scrape hole in fish skin so it can suck blood.
Where are the different cones located on a tree?
Female cones are often near the top of the tree, because wind needs to carry pollen and occasionally the seeds the female ovules produce. MALE CONES?
What are ovules? Where are they formed?
Female sporangium and female gametophyte are both called "ovules." Gametophyte formed in sporangium
diversity among modern amphibians
all are relatively small (paedomorphosis), but there's a lot of diversity in habitat, color, and morphology
What groups of organisms carry out cellular respiration? Where do they live?
all eukaryotes, many prokaryotes. They live pretty much everywhere.
angiosperm life cycle
also see textbook p. 644
basic life cycle of a pine tree
also see textbook page 638
Major characteristic features of the Gymnosperms?
Gymnosperm = "naked seed" no fruits or flowers seed exposed on surface of sporophyll sporophylls arranged in strobili/cones
hardwood vs. softwood as applied to Gymnosperms and Angiosperms?
Gymnosperms (non-flowering/fruiting) have softwood, which has tracheids but no vessel elements. Angiosperms have hardwood - vessel elements and tracheids.
Which macronutrients are "stored" in the soil and protected from leaching? Name three.
H+ > Ca++ > Mg++ > NH4+ > K+ in order of most --> least attracted to soil particles
Why are acidic soils generally low in nutrients?
H+ is more strongly attracted to soil particles than any other cation, so it "bumps off" weaker cations, which are then lost via leaching
What defines where a species lives?
HELP
What's considered the most important pre-zygotic barrier?
HELP ??
What's special about clade Euarchontoglires in terms of number of species?
It's the clade of eutherians that has the most species, because rodents make up about 2,000 out of 5,000 eutherian species!
Constraints of the arthropod exoskeleton: what adaptations does it require? (just name the adaptations - descriptions are on other flashcards)
Jointed limbs, unique form of muscular attachment, Ecdysis (molting)
stromatolites
Layered rock that results from the activities of prokaryotes (especially photosynthetic) that bind thin films of sediment together.
stromatolites
Layered rock that results from the activities of prokaryotes that bind thin films of sediment together.
Lumbricus (earthworm): How does it move? How does it reproduce?
Locomotion: -remember: 2 layers of muscle, outer layer = circular fibers and inner layer = lengthwise fibers -remember: what muscles can do is contract -segments can work independently in terms of muscle action -contract circular muscles --> worm gets long and thin -contract longitudinal muscles --> worm contracts, gets short and thick; setae grip sides of tunnel worm is digging -locomotion = series of peristaltic waves with setae digging into earth Reproduction: -sexual with internal fertilization -genital pores -clitellum secretes ring of mucus that --> cocoon for fertilized eggs while they're in the earth
How did marsupials get to Australia and the Americas?
Long ago (225 mya), all of today's continents were part of one massive continent (Pangaea). As the continents split, Australia and South America were both attached to Antarctica. Then Australia split off from Antarctica, allowing marsupials to evolve there with no competition from eutherians. Because the three continents were originally connected, some marsupials survived and spread through the Americas, but today most species are eutherians.
Name three of the divisions included in the ferns & allies.
Lycophyta: club mosses/spike mosses Sphenophyta: horsetails Pterophyta: ferns
Examples of basidiomycetes?
Maiden veil fungus, puffballs (emit spores), shelf fungi
megabats vs. microbats
Megabats: -larger -"fruit bats"/"flying foxes" -tropical Microbats: -smaller -echolocation --> weird-looking face shape that's adapted for bouncing sound off of it -carnivorous (mostly insects) -includes vampire bats
How does a sponge's size and shape determine the complexity of its water channels?
Metabolic activity happens at the surface of water channels, so bigger and wider sponges have more channels (--> more surface area)
How did today's amphibians evolve form early amphibians?
Modern amphibians are small with childlike proportions. This suggests they may have evolved from Eryops larvae (paedomorphosis).
Examples of ascomycetes?
Morchella esculenta (morel mushroom) Tuber melanosporum (truffle) most unicellular yeasts
Mosses: what do the gametophyte and sporophyte look like?
Mosses have sporophytes that have a clear stalk and capsule. They don't have clear gametangia - they're just at the tips of the leafy gametophytes. The gametophyte is the rest of the moss body, what you typically think of when you think of moss. Gametophytes have stems, leaf-like structures, and rhizoid roots.
diversity of today's mammals by subclass?
Most of today's mammals are eutherians, with some marsupials and very few monotremes
What orders are in clade Euarchontoglires? (ie what types of animals - just memorize their common names)
Rodentia (squirrels, beavers, rats, porcupines, mice) -distinctive teeth: see other slide on this -example species = naked mole rat: lives in underground eusocial colonies in South Africa. Bald minus a few sensory hairs. Lagomorpha (rabbits, hares) -continuously-growing incisors like rodents -hares are born with fur & eyes open & needing less care, rabbits pretty much the opposite Primates (lemurs, monkeys, chimpanzees, gorillas, humans)
Ornithischian dinosaurs vs. Saurischian dinosaurs
Ornithischian dinosaurs: "bird-type hip" - pubis bone points forward (2) Saurischian dinosaurs: "lizard-type hip:" - pubis bone points downward (1) Ornithischian dinosaurs are extinct now, Saurischians are not (modern birds)
How are the feeding features of each kingdom reflected in organisms' body plan?
Plants: photoautotrophs (chloroplasts, leaves, shoot system vs. root system, vascular system) Fungi: heterotrophs or autotrophs, external digestion and absorption (lives inside food, body = mass of interconnected threads - 1 cell thick - with maximal surface area for absorption) Animals: heterotrophs, ingestion and internal digestion (digestive system, circulatory system, muscular system; keen senses)
Get out your phylogeny and make sure you could label everything on a blank one.
Please actually do this.
Make sure you can fill out the phylogeny in the May 6 lecture handout.
Please actually do this.
Make sure you could complete the phylogeny in the May 4 lecture handout: names of subclasses/clades and synapomorphies.
Please actually do this.
Make sure you could map characteristics onto the phylogeny in the 4/20/20 lecture handout.
Please actually do this.
make sure you can fill out the phylogeny of Deuterostomes.
Please actually do this.
parasitic Chytridiomycota
Some chytridiomycota are parasitic on frogs and salamanders responsible for frog declines in Sierra Nevada and other places in world
How do sponges reproduce?
Sponges are hermaphroditic, meaning they have both male and female sex organs. Choanocytes make sperm, amoebocytes make eggs. The eggs stay in the wall of the spongocoel while the sperm float out of the sponge with the water leaving through the osculum. Once an egg is fertilized by another sponge's sperm, it leaves the osculum as a free swimming larva, then settles on the sea floor and develops into a sponge.
Ferns: where are the sporangia located and what is a sorus?
Sporangia are located on the fertile leaves of a strobilus. A sorus is a cluster of sporangia (think of those insect-larvae-lookin-things we looked at in lab)
notochord: -structural characteristics? -function?
rigid, noncompressible (if you press on the ends), flexible, made of collagen/cartilaginous material structural support (stiff rod) --> something for muscles to pull against. Allows muscles to contract on only one side of the body without the whole body scrunching. This allows movement such as swimming via lateral undulation.
Venom is specialized ____.
saliva
What do hagfish eat, and how?
scavenger; navigates by smell and touch has tongue with "teeth" made of keratin uses tongue and "teeth" to tear pieces of flesh off rotting animals; can tie itself into a knot to help it pull better
Why do ferns and their allies grow in habitats that are wet at least part of the year?
sperm are flagellated, so they need water to find the egg
How do mosses disperse to new sites? What is the dispersal unit? What's a peristome?
spore dispersal from sporangium when hygroscopic tissues detect wind peristome (on sporangium) = row(s) of "teeth" made of hygroscopic tissue
sprawling stance vs. erect stance Which two lineages have independently evolved an erect stance?
sprawling stance = limbs rotated out, not directly under body erect stance = limbs directly under body Mammals and dinosaurs both independently evolved an erect stance.
functions of arthropod exoskeleton
structural support protection from mechanical damage prevents water loss (allows colonization of land, including diverse ecological niches such as the desert)
organismal ecology
studies how an organism's structure, physiology, and (for animals) behavior meet environmental challenges
major geological eras
study handout. eras separated by extinctions.
community ecology
study of different species in a particular geographic area trophic webs, symbioses, succession
water cycle, carbon cycle, nitrogen cycle
study your handout
sympatric speciation (examples?)
subset of a population forms a new species without geographic separation eg change in mating patterns - pheromones, what time then mate, etc.
Cretaceous extinction (what and when?)
the extinction of more than half of all species on the planet, including the dinosaurs, about 65 MYA
habitat
the natural home or environment of an animal, plant, or other organism
How do tapeworms feed?
they absorb nutrients from their host's intestine (absorption through body surface)
What adaptations do snakes have for swallowing large prey?
they do NOT unhinge their jaws! 3 adaptations for swallowing large prey: 1. the two sides of their lower jaw are not fused at the midline, but instead connected by stretchy tissue 2. The upper jaw has two rows of teeth - the middle is the pterygoid bone. The two sides of the upper jaw can move independently, meaning the teeth on the pterygoid bone can "walk" over the prey, ratcheting it inside ("pterygoid walk") 3. 2 hinges on each side of lower jaw (thanks to quadrate bone). Length of quadrate bone determines how much a snake can open its jaw.
parts of a pollen grain
thick cell wall = exine, formed by the sporophyte. The exine is sculptured in species-specific patterns and contains sporopollenin, a material resistant to decomposition. gametophyte (1-2 cells with 2-3 nuclei)
triploblastic
three tissue layers: ectoderm, mesoderm, and endoderm
characteristics of Hydrozoa
very diverse (some freshwater, mostly marine) predatory some solitary and some colonial
How widespread and important are mycorrhizae in the biosphere?
very widespread and important (more than 90% of plant species participate in mycorrhizae)
essential steps required for official recognition of a species name
voucher specimen, collector + identifier MORE ??
What is leaching and under what conditions does it occur?
water leaves the soil, nutrients dissolved in water come with it Anions are the ones dissolved in the water, because they're repelled by the soil particles that are also negatively charged UNDER WHAT CONDITIONS DOES IT OCCUR?
post-anal tail: distinguishing characteristics? function?
extends beyond anus (compare to nematodes, which have an anus at the very tip/end of the body); function = locomotion
Ancestors of squamates: Ichthyosaurs and Plesiosaurs
extinct amniote reptiles that secondarily converged on fishes & dolphins (completed transition to land with amniote egg, then returned to the sea) Ichthyosaurs: -converged on fishes and dolphins -lived and reproduced in water (including bearing live young); breathed at water's surface -The picture is of an Ichthyosaur (the powerpoint also has better pictures) Plesiosaurs: -converged on fishes
What are "mammal-like reptiles?"
extinct ancestors of mammals that were reptiles
Enterobius vermicularis (pinworm) life cycle What are the definitive and intermediate hosts?
female lays eggs on infected individual's anus at night, eggs spread (eg infected person touches their anus and then touches a common surface), infection of other people by oral transmission (touch shared surface then touch mouth), eggs hatch and adult worms live in intestine human = definitive host, no intermediate host
approximate time of origin of Plantae kingdom
480-500 million years ago
equation for photosynthesis
6CO2 + 6H2O + light energy --> C6H12O6 + 6O2
general characteristics of Phylum Cnidaria (symmetry? # of tissue layers? body form? digestion? other features?)
9,000 species: jellyfish, anemones, coral, etc. radial symmetry Eumetazoa: true tissues (2 layers = diploblastic) - first animals we've studied that have true tissues! 2 forms: polyp and medusa. An example of medusa form is your classic jellyfish. Depending on the species, they can have phases for both forms or just one. [medusa ~ upside-down polyp] gastrovascular cavity with only one opening = mouth/anus cnidocytes: stinging cells (where the name "Cnidaria" comes from)
What is the chemical composition of plants? From where do plants get essential mineral nutrients?
96% of plants' dry mass is carbon, oxygen and hydrogen. They also have other elements. Except for carbon (from photosynthesis) and some oxygen (from CO2), ALL mineral nutrients come from the soil.
general characteristics of phylum Ctenophora?
= comb jellies (90 species) radial symmetry Eumetazoa: true tissues (2 layers = diploblastic) -mouth and anus are separate (directional digestive tract) -longitudinal rows of plates bearing cilia ("combs") -cilia propel animal forward -glue cells on tentacles for catching food -often bioluminescent -small ("sea walnut") don't sting (lack cnidocytes)
What other animal phylum is most closely related to the chordates? Why do we think so?
??
How do scientists construct phylogenetic trees?
molecular analysis: comparing DNA sequences morphological analysis: compare organisms' body form - this type of analysis is especially useful for extinct species where you have to look at the fossil record
Schistosomiasis: symptoms?
pee blood, person is weakened and sick
What orders are in clade Xenarthra? (ie what types of animals - just memorize their common names)
sloths, anteaters, armadillos sloths have spread to Central America, armadillos have spread to North America
squamates
snakes and lizards
regional influences on plant life/vegetation type? (ie what environmental factors define biomes?)
soil type
characteristics of Scyphozoa solitary or colonial? body form
solitary "classic jellyfish" - medusa form
natural selection
some individuals are more "fit" (in their specific environment) and can produce more viable, fertile offspring --> (eventually) adaptive evolution of the population
What is considered the basic unit of life?
the cell
Gymnophiona (Caecilians): -etymology of name -number of species -habitat -morphology
"Gymnophiona" = "naked snake" (think Gymnosperms, which means "naked seed") -Caecilians: "caecus" = "blind" -171 species -pan-tropical distribution -live in mud or shallow water -elongate, limbless, blind (sense with tentacles) -actually amphibians, not snakes (snakes are reptiles)
Hexapoda body plan
"Hexapoda" = "6 feet" (insects) three tagmata: head, thorax, abdomen thorax contains 3 pairs of legs and 2 pairs of wings (or modifications thereof) note that there can be exceptions to this body plan!
What does the term "amphibian" mean?
"amphi-" = both, "bio-" = "life" animals that live in two worlds: aquatic larvae and terrestrial adults
characteristics of Cubozoa
"box jellies" small; transparent; medusa in form very potent sting (cnitocytes)
sponges: spongocoel
"coel" = "internal cavity/opening"
fungi: what is a heterokaryotic cell, and when, where and how is it formed?
"different nuclei" - more than one type of nucleus in a single cell due to fungal mating (when hyphae of two mating types fuse) NOT the same as diploid. We can say "N + N" but it's two separate nuclei, not one nucleus with multiple sets of chromosomes.
dorsal hollow nerve cord: how is it different from similar structures in other phyla we've studied? How does it form?
"dorsal" and "hollow" distinguish it from other nerve cords we've studied (eg ventral and solid nerve cords in annelids and arthropods) chordate embryo: infolding of dorsal body wall --> pinches off --> nerve cord. (Remember that the nerve cord is above/dorsal to the notochord.)
Characteristics of Phylum Echinodermata -etymology of name -position on phylogenetic tree -status of coelom -symmetry -movement patterns -habitat -morphology, vascular system
"echino" + "derm" = "spiny skin" -Bilateria (bilateral symmetry, triploblastic) -Deuterostomes (like us chordates) -Coelomate -pentaradially symmetrical -slow-moving or sessile -marine -calcium carbonate endoskeleton covered with skin ("spiny skin") -water vascular system (I have a separate slide on this)
What does fenestration mean? Name the different types of skull fenestration in amniotes and the characteristics of each.
"fenestra" = "window." (pl. fenestrae) Fenestration describes how many openings are in the skull aside from the orbit (eye socket) and nostrils. A. Anapsid: orbit + no fenestrae B. Synapsid: orbit + 1 fenestra C. Diaspid: orbit + 2 fenestrae "aps" = "opening" Any of these skull types can be modified, so more derived lineages are more difficult to categorize just by looking at the skull.
Acoelomate
"not having a body cavity"
monoecious
"one home" Gymnosperms: male and female cones are on the same tree
dioecious
"two homes" Gymnosperms: male and female cones are on different trees --> trees can be either male or female
Annelids: septum (pl. septa)
"wall" that divides body segments
Deuteromycota characteristics and life cycle
-"imperfect fungi:" fungi for which no sexual reproduction is known (seem to be members of Ascomycota and Basidiomycota, based in part on the morphology of the asexual sporangia) -"molds" - they only reproduce asexually, so they always look like molds -identified by asexual sporangia life cycle: look at the "asexual reproduction" part of the diagram
General characteristics of Phylum Nematoda (roundworms)? (symmetry? diploblastic or triploblastic? status of coelom?)
-"nema" = "round" -bilaterally symmetrical -triploblastic -pseudocoelomate
Ophiuroidea (brittle stars) characteristics -etymology of name -Why is it called a brittle star? -morphology
-"ophio"= "snake" (arms look snakelike) -called a "brittle star" because its arms break off easily in the event of a predator grabbing one of them --> brittle star can regenerate after escaping -distinct central disk -long, flexible arms -tube feet lack suckers (doesn't use tube feet for gripping)
Urodela (Newts and salamanders): -etymology of name -number of species -habitat -morphology (compare to Eryops) -example of a specific species
-"uro" = "tail" -502 species -distribution is mostly temperate -body plan most similar to early amphibians (Eryops) -live pretty terrestrial lives given that they're amphibians -example: Axolotl, Ambystoma mexicanum
General characteristics of Class Oligochaeta: # species distinguishing physical characteristics muscle arrangement habitat monoecious or dioecious? examples?
-3,000 species -few setae ("chaet" = "hair," "oligo" = "few") -no distinct head -clitellum = broad band-like thing near front end -2 layers of muscle: outer layer has circular fibers, inner layer has lengthwise fibers -freshwater and terrestrial -monoecious examples: Lumbricus ("earthworm"), Giant Palouse earthworm
conservation: declining amphibians How bad is it? (stats)
-32% (known) amphibian species threatened, 43% declining in population -168 species known to have gone extinct in the past 25 years (probably a lot more) -undescribed species are going extinct before they are even discovered -6th mass extinction event for vertebrates in the history of the earth (amphibians lived through the last two, including the dinosaur extinction)
Class Petromyzontida (lampreys): characteristics -number of species -morphology (compare to hagfish, other vertebrates)
-40 species -cartilaginous skeleton, jawless -notochord and rudimentary vertebrae (probably provide some structure and support, but less support is needed when living in water) -lateral eyes -keratinized teeth (like hagfish)
General characteristics of Class Hirudinea ("leeches"): # species morphology feeding habits example?
-500 species -(secondarily) not metameric: their ancestors were metameric, but leeches have lost their internal segmentation and only have external segmentation -posterior and anterior suckers (involved in locomotion) -setae reduced or absent -most are carnivorous, predatory -only a few suck blood of vertebrates example: Hirudo medicinalis ("the medicinal leech")
Class Myxini (hagfish, slime hag): characteristics -number of species -importance of studying them? -habitat -morphology
-65 species -studying them can inform us about our shared ancestor -habitat: bottom of the sea -elongate body -cartilaginous skeleton (no bones) -brain and braincase (encases brain) -notochord and rudimentary vertebrae -pharyngeal (gill) slits -no eyes & no jaws -pores of slime glands -mouth surrounded by barbels (sensory tentacles)
anamniote egg vs. amniote egg: name the parts and their functions
-Anamniote egg: -embryo (developing baby) -yolk sac (provides nourishment for developing embryo via the embryo's digestive tract) -embryo is always in water --> waste washes away easily (eg. frogs) Amniote egg: -embryo -yolk sac -allantois (waste sac) -amnion (creates water sac around embryo) -chorion -terrestrial --> need amnion to create water bath so the embryo doesn't dry out -waste can't wash away like it does in an anamniote --> necessity of allantois -can have a shell, or not see powerpoint/handout for a better diagram
General characteristics of Phylum Mollusca Symmetry Status of coelom # species
-Bilateral symmetry -Coelomate (triploblastic) -Lophotrochozoa 50,000 living, described species, but many more extinct species (good fossil record due to their shells)
Examples of nematodes (roundworms)
-Caenorhabditis elegans -Turbatrix aceti (vinegar eel) -Enterobius vermicularis (pinworm) -Necator americanus (hookworm) -Trichinella spiralis (trichinellosis) -Ascaris lumbricoides (large roundworm of humans) -Wuchereria bancrofti (filariasis)
major phyla of fungi
-Chytridiomycota -Zygomycota -Ascomycota -Basidiomycota -Deuteromycota (includes Ascomycota and Basidiomycota) -Glomeromycota
examples of Sarcopterygians (lobe-finned fishes)
-Dipnoi: lungfishes (can pull themselves around on land using their lobed fins!) -Actinistia: Latimeria, the Coelacanth (named after Marjorie Latimer) -tetrapods: amphibians, "reptiles," mammals, birds
basic characteristics of arthropods: clade on phylogenetic tree symmetry stats of coelom
-Ecdysozoans -Bilaterally symmetrical -Coelomate (but coelom reduced)
Schistosomiasis: what should be done about it?
-Medicine clears up infections but won't prevent reinfection. -You can tell people not to go in the water, but that's not super feasible when people bathe/wash clothes/etc. in the water as part of daily life. -Can spray poison in water to kill snails, but this is bad for the ecosystem -Best solution: better toilet facilities -->less urine and feces in water (urine and feces carry the eggs)
Mammalian subclasses
-Monotremes ("egg-laying mammals") -Marsupials (Metatheria) -Eutherians ("placental mammals"/true mammals)
What are the eutherian equivalents of the following Australian marsupials? -Planigale -Marsupial mole -Sugar glider -Wombat -Tasmanian devil -Koala -Kangaroo
-Planigale & mouse -Marsupial mole & placental mole -Sugar glider & flying squirrel -Wombat & larger rodents (eg gopher) -Tasmanian devil & badger, raccoon, etc. -Koala & sloth -Kangaroo & deer
How can Echinoderms be part of clade Bilateria if they're pentaradially symmetrical?
-Their larvae are bilaterally symmetrical -fossil record shows that earliest Echinoderms were bilaterally symmetrical ...therefore Echinoderms are secondarily pentaradially symmetrical, so it's ok for them to be classified under Bilateria
Trilobitomorpha: habitat morphology other characteristics importance
-Trilobites -marine -3-lobed body plan ("tri-") -all extinct -abundant in fossil record, especially Cambrian --> Carboniferous -Importance: before carbon dating, certain types of trilobites (known to be from certain periods) could help date other fossils
Regeneration in sea stars: how does it work and why should we care?
-a limb cut off will grow back -a limb cut off with some of the central disk attached will grow a whole new sea star -why we should care: we can't regenerate limbs, but like us Echinoderms are deuterostomes --> could we learn how to regenerate ourselves?
Crocodilians: -evolutionary and phylogenetic importance -other cool morphological features
-a lineage of Archosaurs -ancient lineage that used to be much more diverse than it is today -coexisted with dinosaurs -secondary palate --> can lie below water's surface while breathing through nostrils
Trichinella spiralis life cycle What are the definitive and intermediate hosts?
-adult worms live in small intestine, mate, lay eggs -larvae circle around body and make intracellular cysts in striated muscle -cysts can be in the heart or brain (very bad!!) -contracted via eating meat with these cysts that hasn't been cooked/inspected properly (humans and pigs both get it from eating pork) I think humans and pigs are both definitive hosts and there's no intermediate host?
Cane beetle (characteristics and efforts to control)
-agricultural pest for sugarcane -Australia, 1930s: introduced toads (Cane toad) in an effort to control beetles -toad introduction did more harm than good since they're poisonous, large and predatory
How does the swim bladder work to maintain neutral buoyancy?
-air-filled sac against back of body cavity, sometimes attached by duct to pharynx -Problem 1: fish are denser than water, so without help they'd just sink -Solution 1: swim bladder offsets density of fish because it's filled with air, which is less dense than water -Problem 2: If the fish swims deeper, more water pressure causes the swim bladder to compress; if the fish swims up, less water pressure causes the swim bladder to expand. This throws off neutral buoyancy. -Solution 2: The fish can modify the amount of air in its swim bladder (through a duct connecting swim bladder to pharynx, through circulatory system, etc) --> can swim at a range of depths
Cephalochordates: characteristics -other names for this group -etymology of "Cephalochordate" -morphology -evolutionary importance -life cycle
-aka Amphioxus or Branchiostoma -"Cephalo" = "head" (like in cephalopod) -they are chordates: notochord, dorsal hollow nerve cord, post-anal tail, endostyle -water passes through pharyngeal slits, food trapped in endostyle, etc. -represents anatomy of our ancestors (most basal branch of chordates) -life cycle: adult filter-feeding in burrows, comes out to reproduce --> larvae
Phylum Hemichordata: characteristics and example -position on phylogenetic tree -habitat -morphology (what do they share with chordates?)
-aka enteropneusts -sister group to echinoderms (similar larvae) -wormlike, marine, dorsal & ventral nerve cords (not hollow) -no notochord, endostyle, or post-anal tail -yes pharyngeal slits example: acorn worms (burrow on beach --> make fecal coil)
Urochordates: characteristics -other names for this group -etymology of name -movement patterns -independent or colonial? -feeding mechanism -morphology -life cycle -compare morphology of larvae and adults
-aka tunicates (because the body has a sort of tunic around it), "sea squirts" (because they suck in water and squirt it out), "sea grapes" (because colonies look like bunches of grapes) -"uro" = "tail" -sessile, colonial -filter feeders -incurrent and excurrent siphons (sea SQUIRTS), pharyngeal slits, endostyle --> esophagus --> digestion -larvae = "tadpoles." Not really tadpoles, but they look like them. free swimming --> disperse species even though adults are sessile. Larvae settle on substrate, then mature into a sessile adult with no tail. -larvae have notochords, dorsal hollow nerve cords, post-anal tails -larvae are more like other chordates than adults -paedomorphosis: retention of juvenile/larval characters in adult
Anctinopterygians: -number of species -distinguishing morphology
-almost 30,000 species -ray-finned fishes
Order Hymenoptera (insects): characteristics and examples -etymology of name -how do they live? social structure?
-ants, wasps, bees; "Hymenoptera" = "membranous wings" -eusocial = reproductive specialization: *sterile individuals carry out work caring for the reproductive members of the colony *workers = sterile females *drones = fertile males *queens = fertile females (a nest may have multiple queens) -workers do all the work without reward of passing on their own genome --> is an ant colony or beehive a superorganism?
General characteristics of snakes: -number of living and described species -feeding habits
-approx. 3,300 living, described snake species (600 of which are venomous) -All snakes are carnivorous; most will not accept dead food under natural conditions -ingest prey whole
Sarcopterygians: -number of species -distinguishing morphology
-approx. 30,000 species (if you include terrestrial species such as ourselves) -lobe-finned fishes
Zygomycota characteristics and life cycle
-asexual reproduction prominent - therefore often called "molds" -microscopic sexual structures (called "zygospore" or "zygosporangium"), which are produced amongst the hyphae growing in the food medium. They consist of a single cell with many diploid nuclei. -zygosporangium goes dormant until conditions are favorable -coenocytic - not enough cell support to make large sexual bodies Asexual cycle is the main form, sexual reproduction occurs mainly when conditions change
Taenia solium (pork tapeworm) life cycle definitive and intermediate hosts?
-basically same life cycle as beef tapeworm (definitive host = humans, intermediate host = pigs) -cystercosis is possible (this has its own slide)
Order Coleoptera (insects): characteristics and examples -etymology of name -# of species -habitat and diet -anatomy (define elytra and alae) -life cycle
-beetles; "Coleoptera" = "sheathed wing" -350,000 described species, real number more like 5-8 million -wide variety of terrestrial habitats and diets -anatomy fairly uniform: *elytra = hard forewings not used for flying, protect *alae = second pair of wings underneath elytra - these are used for flying -life cycle: egg --> larva --> adult -larva does the most feeding and is the worst pest in pest species ladybug (example of a beneficial pest-control species); Cane beetle (example of an agricultural pest) — I have a separate slide for Cane beetles
General characteristics of Phylum Annelida (segmented worms): Symmetry What characteristic distinguishes them as Lophotrochozoa? # of tissue layers Status of coelom Circulatory system Nervous system Other characteristics?
-bilaterally symmetrical -Lophotrochozoa: trochophore larvae -Coelomate (triploblastic) -closed circulatory system (continuous blood flow within system of complex vessels, as opposed to an open circulatory system which has simpler open-ended vessels) -ventral nerve cord (ie on underside of worm) -metameric
Order Lepidoptera (insects): characteristics and examples -etymology of name -characteristics -mimicry
-butterflies, moths; "Lepidoptera" = "scaly wings" -butterfly wings, when magnified, look like reptile scales -characteristics: see slide on differences between butterflies and moths -mimicry: Batesian and Müllerian (Monarch butterfly and Viceroy butterfly) - see other slide on this
diversity of nematodes: -free living or parasitic? -habitat -# species -morphology
-can be free-living or parasitic -occur in almost every possible habitat -12,000 species described; probably 500,000 more not yet "discovered" -bias in studying nematodes: focus on parasites of humans -morphological similarity across taxa (appearance is fairly conserved)
Ascaris lumbricoides (large roundworm of humans) life cycle What are the definitive and intermediate hosts?
-can contract these worms by ingesting their eggs (eg through touching contaminated fecal matter and then touching your mouth) -if swallowed, eggs mature in small intestines --> adult worms mate and lay eggs -eggs expelled in feces humans = definitive host, no intermediate host
structure of a turtle: -carapace -plastron -Does it have teeth? -Where is the vertebral column? -Where are the ribs?
-carapace = top side of shell -plastron = underside of shell (kinda like the stomach region?) -has a beak instead of teeth -The vertebral column is fused to the inside of the carapace. -The ribs form the basal structure for the carapace.
hydatid cysts (a type of cystercosis)
-caused by dog tapeworm -big cysts filled with fluid (many small cysts all together)
Describe the biology of examples of zygomycetes - Rhizopus
-commonly called black bread mold -grows on solid substrates in terrestrial habitats -grows on bread alongside other molds such as Penicillium -black spores --> sporangium appears black
Filariasis
-condition caused by Wuchereria bancrofti infection -long-term damage to the lymphatic system (clogging up, irritation) -body lays down a lot of extra tissue for protection
Holothuroidea (sea cucumbers) characteristics -body plan/morphology -symmetry
-cucumber shaped body -5 rows of tube feet + extra tube feet - modified for feeding -reduced skeleton - no spines (soft-bodied) -ossicles: small calcareous elements embedded in the dermis (part of endoskeleton; rigidity and protection) -superficially appear bilaterally symmetrical, but their body plan is really more like a stack of sea stars -If you look at the mouth head-on, you can see some of the pentaradial symmetry -5 teeth near mouth, 5 rows of tube feet
Nematode morphology: shape size tissue arrangement musculature digestive system nervous system
-cylindrical ("roundworms" because they're round in cross-section) -non-living cuticle secreted by epidermis --> nematodes are Ecdysozoa -triploblastic -hydrostatic pressure of pseudocoel (allows for something stiff that muscles can pull on, like how our muscles pull on our bones) -no circular muscles (only longitudinal) --> in order to move, worm tightens one side of its muscles, and then the other so that it thrashes side-to-side (lateral undulation) -digestive tube (mouth to anus) -dorsal and ventral nerve cords -size range from a few mm to 1m
skates and rays: -defense mechanisms -examples
-defense mechanisms: venom barbs; electric shocks from specialized muscles -many are harmless -examples: stingrays, electric rays
Echinococcus granulosus (dog tapeworm) life cycle definitive and intermediate hosts?
-definitive host = dogs and other carnivores -intermediate host = sheep, goats, swine, etc. -causes hydatid cysts (this has its own slide)
Taenia saginata (beef tapeworm) life cycle definitive and intermediate hosts?
-definitive host = humans -intermediate host = cow -cow ingests proglottids, which were passed into the environment via feces -oncospheres (larvae) develop into cysterci in muscle -humans get the tapeworm if they eat this beef without cooking it properly -tapeworm reproduces in humans
evolution of hair
-derived from scales -preadaptation: hair probably first evolved for a sensory function (before endothermy evolved), later became useful for insulation
How does a sea star feed on a bivalve?
-difficult feat! Bivalve adductor muscles mean it's very hard to open -sea star wraps around ventral margin of bivalve -uses tube feet to force valves apart -when there is a 0.1 mm opening, sea star's stomach comes out of its mouth and into the bivalve shell -digestive enzymes further weaken adductor muscles -extracellular digestion by stomach, which is now inside the Bivalve
Bony fish: what are the names of their different types of fins and where are the fins?
-dorsal fin (one or more on midline of fish) -caudal fin (midline; varies in shape) -anal fin (midline) -pectoral fins (paired) -pelvic fins (paired) see handout for where these are
Order Diptera (insects): characteristics and examples -etymology of name -distinguishing morphology
-eg flies, mosquitos; "Diptera" = "two wings" -only one pair of wings (2nd pair is reduced/vestigial and modified into halteres, which vibrate during flight) -scavengers, predators, parasites, vectors of disease -sucking, piercing mouthparts eg. Tumbu fly (larvae develop under human skin, forming a bump in skin, after parental fly lays eggs on damp clothing. to treat: put Vaseline over the bump where the larvae is developing to cut off its oxygen supply)
Necator americanus (hookworm) life cycle What are the definitive and intermediate hosts?
-eggs exist on the ground, hatch into larvae -person walks barefoot --> larvae tunnel through skin of feet -larvae move through bloodstream to lungs --> infect lungs --> person coughs and swallows worms into digestive tract -worm attaches to wall of intestine, matures, lays eggs -eggs passed in feces definitive host = humans, no intermediate host
Class Ostracodermi (Ostracoderms): characteristics -etymology of name -morphology -feeding habits -other distinguishing characteristics
-extinct -"ostraco" = "armor," "dermi" = "skin" -small fish -heavily armored on the outside ("armor" made of bone), but internal skeleton made of cartilage -purpose of plating/armor = protection, mineral reserves? (like us) -no jaws --> filter feeding by pumping water through pharynx and out through gill slits
Class Placodermi (Placoderms): characteristics -morphology -size -other distinguishing characteristics
-extinct -jaws!! (represent the point at which the vertebrates began to rule the sea, rather than cephalopods) -heavy external armor -cartilaginous internal skeleton -vertebral column -some very large (several meters in length)
Axolotl, Ambystoma mexicanum
-famous for paedomorphosis (looks like a larva) -never undergoes metamorphosis
Crinoidea (sea lilies, feather stars) characteristics -general morphology? -Why are they called "sea lilies?" -other characteristics?
-feathered arms (crinoids) surrounding upward pointing mouth (kinda like an upside down echinoderm) -called "sea lilies" because they look like flowers -impressive fossil history - eg Cambrian period
Siphonaptera: etymology and characteristics
-fleas; "Siphonaptera" = "wingless tube" -wings can be secondarily lost among Hexapoda -fleas are ectoparasitic
How do flowers reward pollinators?
-food: nectar, petals, pollen -mating sites (deception = mimic females) -oils: mating attractants -egg-laying sites (more deception)
Turbatrix aceti (vinegar eel) characteristics: -free-living or parasitic? -size -habitat
-free-living -pretty small (barely visible with the naked eye) -live in low-pH habitats (eg vinegar) -not parasitic (harmless to humans)
General characteristics of Class Turbellaria? -freeliving or parasitic? -habitat -example
-free-living (not parasitic) -marine or freshwater -eg Planaria
morphology of female nematodes
-genital pore --> reproductive cavity -ovary, uterus, etc.
Chytriodiomycota characteristics and life cycle
-habitat: aquatic or wet soil (only fungi with flagellated spores) -uni- to multicellular; phylogenetically, this is the basal group in the Fungi kingdom -zoospores (flagellated spore)
Hemotoxic venom: Viper family (vipers, rattlesnakes, etc.) -How does it work? -At what stage of eating prey (capturing, killing, swallowing, digesting)? -If a human is bitten, what are the effects?
-hemotoxic venom = digestive enzymes -works at the digestion stage to digest the prey from the inside out -effects of a bite: tissue damage, internal bleeding, bruising, etc.
Wuchereria bancrofti life cycle What are the definitive and intermediate hosts?
-human gets infected via mosquito bite -larvae move into lymphatic system and mature there --> adults produce lots of larvae -a different mosquito bites infected human --> mosquito contracts L1 larvae, which mature in mosquito to --> L3 larvae (able to infect another person) human = definitive host, mosquito = intermediate host (only a specific species of mosquito)
"swimmer's itch:" how are humans affected? how seriously?
-humans are not actually part of the life cycle, but the parasite can mistake a human for a duck and infect a person instead -cercariae penetrate skin and cause dermatitis (itchy rash). life cycle of the schistosome is not completed. -symptoms are not super serious in humans
How serious a danger is snakebite? What determines this when you look at different parts of the world?
-in the developed world: danger to humans is negligible. -in the developing world: snakebite is a very serious public health problem. Snakes are not the problem; poverty and lack of infrastructure are. You need to be able to avoid snakes, and you need to be able to get treated if you get bitten.
How does Class Bivalvia form pearls?
-inside of shell has smooth iridescent coating (nacre, "mother and pearl") -grit gets between mantle and shell --> mantle surrounds grit w/ coating --> pearls
Characteristics of Class Cestoda (tapeworms)? What is a scolex? What are proglottids?
-large and parasitic (up to 20m in length!) -scolex = front end = where the tapeworm anchors to the inside of the host intestine (via hooks and suckers) -scolex =/= mouth, only anchor -made up of pieces/segments = proglottids
Why is radial symmetry adaptive for echinoderms?
-lifestyle: radially symmetrical animals tend to be sessile or slow-moving -structure: pentaradial symmetry is structurally stronger. There's one sea star species with 6 arms, but hexaradial symmetry is easier to break in half.
Basidiomycota characteristics and life cycle
-macroscopic sexual structures above or below ground, in which each zygote cell produces a "club-like" sporangium to release haploid spores (basidiospores) -fewer species than Ascomycota BUT diverse sexual body forms
Ascomycota characteristics and life cycle
-macroscopic sexual structures, in which each zygote cell produces a "sac-like" sporangium to release haploid spores: meiosis --> 4 haploid spores --> 8 haploid spores via mitosis -includes some unicellular yeasts
Phylum Ectoprocta characteristics habitat clade on phylogenetic tree
-marine -Lophotrochozoa: lophophore feeding structure shown in an earlier lecture as an example of a lophophore feeding structure
Phylum Brachiopoda characteristics habitat clade on phylogenetic tree morphology archaeological importance
-marine -shell looks like bivalve molluscs -inside: not like Bivalvia -clade Lophotrochozoa (lophophore feeding structure) -shell preserves well in fossils
Zygomycota: what is a zygospore/zygosporangium? When and how is it formed? What does it produce?
-microscopic sexual structures -produced amongst the hyphae growing in the food medium -consist of a single cell with many diploid nuclei -zygosporangium goes dormant until conditions are favorable
How do nipples develop? Why do male mammals have nipples?
-milk line/milk ridge is present in mammalian embryos before sex differentiation -milk line corresponds to nipple location in developed mammal (number of nipples corresponds to typical number of offspring) -supernumerary nipples sometimes occur on milk line (below two main nipples) Male mammals have nipples because the milk ridge develops before sexual differentiation in an embryo.
Class Chondrichthyes: -what types of animals are included? -how many species? -morphology
-name means "cartilaginous fishes" -sharks, skates, rays -970 species -cartilaginous internal skeleton -vertebral column -jaws I have a slide for skates/rays and one for sharks.
Neurotoxic venom: Cobra family (cobras, coral snakes, etc.) -How does it work? -At what stage of eating prey (capturing, killing, swallowing, digesting)? -If a human is bitten, what are the effects?
-neurotoxic venom acts on the nervous system to block synapses and junctions --> paralysis -works at the capturing and killing stage -effects of a bite = paralysis, neurological damage
"Spitting cobras" -differences in fangs between non-spitting cobras and spitting cobras? -What are elapid snakes?
-non-spitting cobras: fangs are roughly equivalent to hypodermic needles that inject venom into prey -spitting cobras: venom travels down fang, bounces out frontward from opening at bottom -elapid snakes = venomous snakes with hollow fangs (cobra family)
lamprey life cycle (how do they mate? what does "petro-" mean in Class Petromyzontida?)
-ocean, parasitic -only feeds while in ocean -when ready to breed: migrates to freshwater streams to mate, then dies -Ammocoetes larva - similar to Amphioxus -juveniles return to sea mating: female attaches to a stone and male attaches to female. female lays eggs & male fertilizes them by spraying his sperm. "petro" = "stone," as in the stone the female attaches to. This picture of the life cycle isn't as good as the one in the powerpoint.
Eryops
-one of the earliest amphibians -larger than today's amphibians (Eryops skull was the size of a toilet seat!) -walked on land using limbs with 5 fingers -eyes on top of its head, like a hippo/crocodile
Dinosaurs: -Where are they on the phylogenetic tree? (What group do they fall under?) -what feature are they characterized by? -What are the two main lineages of dinosaurs?
-one of the lineages of Archosaurs -characterized by an erect stance -2 main lineages of dinosaurs: Ornithischian dinosaurs and Saurischian dinosaurs (see other slide on this)
Pterosaurs: -Where are they on the phylogenetic tree? (What group do they fall under?) -example species -What's special about them?
-one of the lineages of Archosaurs -extinct -eg. pterodactyl -one of three vertebrate lineages to independently evolve flight -ecologically replaced by living birds
Monotremes (egg-laying mammals): -number of species; examples -etymology of name (what's a cloaca?) -other distinguishing morphology -what's unique about their mammary glands?
-only 3 species: Duck-billed platypus and 2 species of Echidna (spiny anteaters) -"mono" + "trema" = "one" + "opening." Monotremes have a cloaca, which is a single opening for the end of the digestive tract (instead of ureter + anus) -cloaca informs us about our shared ancestors -no nipples; instead the female has two parallel troughs down her front which are filled by milk glands -Platypus: venom-conducting spur on hind leg, bill like a duck
Giant Palouse earthworm
-originally considered a cryptid based on early settlers' descriptions (they said it was huge, spit venom, smelled like lilies) -rediscovered; in reality, it's basically a larger earthworm (can be 30cm in length)
layers/components of amphibian skin
-outer layer = epidermis, which is soft and vulnerable to desiccation (similar in structure to fish skin, but fish don't need to worry about desiccation) -mucus glands --> slime on skin -poison glands -chromatophores --> color of skin see the powerpoint for a diagram
Characteristics of Class Monogenea
-parasitic -parasites on gills of fishes (gills have blood supply) - generally not a huge issue, but problematic when lots of fish are living in close quarters -other examples: parasitic on frog bladders and hippo eyeballs
Enterobius vermicularis (pinworm) characteristics: -free-living or parasitic? -size -what to do about them?
-parasitic - really common, esp. in children -small but visible to the naked eye -infection is curable via medicine; often need to disinfect surfaces to prevent immediate reinfection
Ergot
-parasitic on grasses (cereals), esp. rye (because rye grows in cooler climates than wheat) -fungus envelops entire grain -produces toxic alkaloids, which cause gangrene, abortions and death (bad for cows and other livestock that eat the grasses) -hallucinations (LSD) due to alkaloids that include lysergic acid diethylamide
Necator americanus (hookworm) characteristics
-parasitic, more harmful than pinworms -found in warmer parts of the world -specialized front end ("hook") attaches to wall of intestine --> able to suck blood -causes anemia
Trichinella spiralis characteristics
-parasitic, small -largest intracellular parasite -humans & pigs can both contract it (physiologically similar enough - think pork tapeworm) -relatively rare in developed world, commonest source = meat from hunters that undergoes less inspection than grocery store meat -causes Trichinellosis
What is soil? Describe the main components: -how are they arranged in the soil? -how do they affect the health (life) and thus nutrient content of the soil?
-parent rock (and weathered rock particles) -organic matter: living (including decomposers) and dead (source of non-rock nutrients) -water -air (O2) Parent rock is in a layer below the soil, with less and less of it as you go toward the soil surface. Organic matter is most concentrated near the soil surface and least concentrated at the parent rock below the soil. Air and water are dispersed throughout the soil; more water means less O2 since oxygen doesn't dissolve well in water. Parent rock allows some nutrients to stay in the soil. Live organic matter breaks down dead organic matter to make its nutrients available. A lot of nutrients are dissolved in water, and there are air pockets in the soil.
scorpions (Deathstalker scorpion, Fat-tailed scorpion, etc.) -habitat -morphology -reproduction
-part of subphylum Chelicerata within Arthropods -found worldwide -pincers and stinger -small pincers usually mean sting is dangerous -reproduction: live-bearing (as opposed to laying eggs); very affectionate mothers -Fat-tailed scorpion coexists better w/ people --> gets stepped on more --> causes lots of harm ("more dangerous" than Deathstalker scorpion)
General characteristics of Class Polychaeta: # species habitat morphology monoecious or dioecious? examples?
-polychaeta = "very hairy" -5300 species (2/3 of all annelids!) -mostly marine: sedentary or errant (wandering) -head with eyes and tentacles -parapodia with setae ("foot-like" - involved in respiration and locomotion) -heads can have jaws, pincers, eyes, etc. (much more specialized than Oligochaeta) -can be monoecious or dioecious examples: Nereis sp. (ferocious marine worm), Christmas tree worm and Feather duster worm
Ascaris lumbricoides (large roundworm of humans) characteristics
-really big --> can cause a lot of internal damage to the intestines and other organs -treatable with medicine, but also public health efforts --> less feces on the ground (helps disrupt the life cycle of all parasitic roundworms)
"Swimmer's itch:" what is it? What is the life cycle/definitive and intermediate hosts?
-schistosome parasites of birds -definitive host = duck/loon -intermediate host = snail -humans are not part of the life cycle
sharks: -what is their skin like? -diversity/examples
-skin: feels like sandpaper due to denticles on outside (enamel and dentin) -ecologically very diverse -examples: Basking shark, Whale shark, Thresher shark, Megamouth shark, Spited pygmy shark, Tiger shark, Great white shark, Shortfin mako shark, Bull shark, Sawshark, Nurse shark, Hammerhead shark, Angel shark
morphology of male nematodes
-smaller than females -spicule = intromittent organ (the organ that introduces sperm into the reproductive tract of the female) -spicule: connected to ejaculatory duct; retractory muscle controls its movement
How do some fishes manage without lungs or swim bladders?
-special shape of caudal fins (eg. in sharks) pushes the fish up as it swims -sharks: huge oily liver --> buoyancy because oil is less dense than water -lamprey: spends most of its life attached to another fish, feeding parasitically --> lamprey doesn't need to swim on its own -hagfish: adapted to living at the bottom of the sea
What's a spermatophore? How does it allow some salamanders to reproduce on land?
-spermatophore = blob of sperm on a stalk of jelly -female comes along and fertilizes her eggs using the spermatophore (internal fertilization - compare to frog mating) -female then lays eggs in wet moss --> cares for them (not much involvement of father) -sometimes: courtship ritual can persuade a female to choose a specific spermatophore -some male salamanders will deposit their sperm on top of a different male's spermatophore to take advantage of another's courtship ritual
Asteroidea (sea stars) characteristics -shape, morphology -digestive system
-star-shaped with multiple arms -mouth on bottom, anus on top -each arm has same internal structure -digestive system (see diagram in powerpoint): mouth, anus, two stomachs (oral/cardiac and aboral/pyloric), pyloric cecum (gland that secretes digestive enzymes) -strong enough to eat a Bivalve! (I have another slide on this)
How does a snake digest another snake? What has to happen to the stomach?
-stomach stretches really thin to accommodate large prey -digest soft tissue first --> stomach shrinks, compressing prey's backbone -eventually all that's left of the prey is its vertebrae
Ferns and allies: body structure, life cycle, reproduction?
-vascular (lignified xylem) during sporophyte -sporophyte can tolerate seasonally drier conditions (because it's vascular) -sporophyte body can become large (because it's vascular) -plants still need moist habitat for growth during non-vascular gametophyte stage -sporophyte-dominant -sporophyte initially dependent on gametophyte, later independent (gametophyte dies) hygroscopic tissues in sporangium
Echinoderm vascular system
-water vascular system -ring canal: around stomach (center of sea star) --> water moves along radial canals to get to each arm -bulbs fill tube feet with sea water -tube feet: at bottoms of arms, used for suction (attachment to surface) and locomotion -madreporite: on surface of sea star; plate with pores (connected to a canal) that water can enter through
Caenorhabditis elegans characteristics (free-living or parasitic? size? other characteristics?)
-widely-used model organism -first nematode to have its full genome sequenced -free-living -microscopic
basic molluscan body plan 3 main parts + other random body features/details: digestive system, radula, odontophore, nephridium
1) muscular foot = big muscular piece on underside, used for locomotion 2) visceral mass = blob of internal organs 3) mantle = thin, smooth layer under shell (or under where the shell would be) -has a mouth/head end -intestine goes mouth --> anus -radula = tooth-like scraping structure (to scrape nearby surfaces) - part of mouth -radula is connected to odontophore (tongue-like structure) -gills -nephridium - functions like a kidney
When did life move from water onto land? What allowed this to take place?
500 million years ago; ozone in atmosphere allowed it (oxygen from photosynthesis in water)
evolution of lungs and swim bladders?
1. Lungs evolved as outpocketings of the pharynx in fishes gulping air at the surface in shallow, stagnant water. 2. In some fishes (e.g. most Actinopterygii), the lungs became further modified to form a swim bladder for buoyancy, either partially or completely pinched off from the pharynx. 3. In other fishes (e.g. Sarcopterygii, including terrestrial forms) the lungs were kept.
What are the arthropods' four "secrets" of success?
1. Metamerism 2. Exoskeleton 3. Haemocoel 4. Metamorphosis I have a separate slide for each of these.
How can plants increase nutrient uptake through symbioses? Describe three different cases.
1. Mutualism: nitrogen-fixing bacteria inside legumes' root nodules 2. Mutualism: Mycorrhizal fungi (plant roots) 3. ??
How did jaws evolve?
1. Pharyngeal slits in the earliest chordates were used for filter feeding. These organisms got their oxygen by diffusion through their skin, which was okay because they were small animals that didn't need a lot of oxygen to stay alive. 2. As chordates became larger, pharyngeal slits were co-opted to serve as gills. 3. Bars or cartilage (pharyngeal arches, or branchial arches) between the gill slits helped to provide structure to the gill slits. 4. Jaws evolved by co-opting the first branchial arch. With jaws came real teeth from dermal armor, as opposed to keratinized teeth.
How does the ovule develop into a seed?
1. Pollination: transfer of pollen to female receptive site -abiotic vectors (wind, water) -biotic vectors (animals) (Gymnosperms: mainly wind, some insects / Angiosperms: mainly animals, some wind) 2. Pollen germination: forms cytoplasmic pollen tube (containing the sperm) that grows to and into the ovule, discharging sperm nuclei for fertilization (Gymnosperms: can take one year / Angiosperms: can take only a few hours) 3. Fertilization: fusion of egg and sperm to form zygote (2N) cell (Gymnosperms: simple fertilization / Angiosperms: double fertilization - 2 sperm - zygote (2N) AND endosperm (3N)) stigma recognizes pollen grain as compatible via chemical signaling. Chemical gradients guide pollen to an unfertilized egg and guide the sperm down the pollen tube.
What modulates plant growth?
1. internal factors: hormones - many in plants, each with multiple functions -hormone = molecule made in one part of body with impact in another part of body 2. external factors: BIOTIC EXTERNAL FACTORS -consumers: herbivores and fungi (parasites/predators) -N-fixing bacteria --> mutualistic mycorrhizae -competition with other plants ABIOTIC EXTERNAL FACTORS -light: necessary for photosynthesis. light receptors receptors (all cells) perceive light: measure shade, day/night length (season) -temperature (helps to have an annual habit that includes dormancy during unfavorable conditions) -water -soil nutrients
You are a chordate, so where are your: 1. pharyngeal slits? (What's First Arch Syndrome?) 2. dorsal hollow nerve cord? 3. post-anal tail? 4. notochord? 5. endostyle?
1. pharyngeal slits: clefts and arches are present in human embryo --> close up; develop into sound transmission bones, cartilage near ear, various bones If pharyngeal slits don't develop properly in the embryo, the person is born with First Arch Syndrome, which causes a misshapen jaw/head, deafness, etc. 2. dorsal hollow nerve cord: spinal cord + evolution of the whole human nervous system 3. post-anal tail: coccyx (tail bone) - vestigial 4. notochord: main body of vertebral column: vertebrae, intervertebral discs 5. endostyle: thyroid gland is homologous to endostyle (produces hormones; most evolutionarily ancient endocrine gland)
What are some ways in which plants can cope with nutrient-deficient soils?
1. roots increase cation nutrient uptake as a consequence of their metabolism -cellular respiration in root hair cells --> release CO2 into water in surrounding soil -CO2 forms carbonic acid, which then dissociates to form H+ ions -cation exchange at soil particles: H+ bumps off other cations -macronutrient cations that were bumped off are absorbed into the root hairs when they take in water 2. symbioses 3. predation: carnivorous plants
What evolutionary advantage do seeds confer on terrestrial plants over spores?
1. survival of whole plant as dormant embryo (vs. only single cell in spore) 2. protection and complex control of germination by parental seed coat (vs. only thick cell wall & simple germination requirements in spores) 3. endosperm provides abundant energy reserves for germination 4. enhanced, directed, long-distance dispersal by especially animals (vs. more random wind dispersal of small spores)
meiosis: how is it different from mitosis? How do eukaryotes use it?
2 cell divisions to form 4 haploid cells. Used in sexual reproduction.
Deuterostome vs. Protostome
2 modes of development that produce similar adult body plans (on a very, very basic level) "stome" = "mouth," "proto" = "first/early," "deutero" = "second" protostome: mouth develops first, then spiral cleavage. first infolding becomes mouth, then anus forms later deuterostome: mouth develops second, then radial cleavage. first infolding becomes anus, then mouth forms later spiral vs. radial cleavage: look at the powerpoint
When did eukaryotes appear (Protista)?
2.1 billion years ago
Permian extinction
251 million years ago. Over 90% of species extinct (volcanic eruptions, no sunlight, etc). Allowed for the emergence of cone-bearing plants, dinosaurs and mammals.
Cambrian explosion (when?)
535-525 million years ago: huge increase in biodiversity of many animal phyla (in water). Animals were around already, but this is when diversity really exploded.
when did prokaryotes appear (first evidence of life)?
3.5 billion years ago
numbers of eukaryotic vs. prokaryotic cells in humans?
30 trillion eukaryotic, 37-39 trillion prokaryotic
age of earth
4.6 billion years
phylogenetic tree
A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms aka phylogenetic hypothesis - phylogenetic tree can change with new evidence The nodes can rotate and still represent the same relationships
homology
A character in two organisms is homologous if it is derived from the same character in a shared ancestor.
Carnivore
A consumer that eats only animals.
herbivore
A consumer that eats only plants.
How do leeches move? on land? in water?
A leech has circular and longitudinal muscles, but the muscles can't produce peristaltic waves because there's no internal segmentation. on land: alternate which sucker is holding on to the ground in water: swimming via dorsoventral (up and down) undulation
keystone species
A species that influences the survival of many other species in an ecosystem eg: otters eating sea urchins, thus protecting kelp figs feeding many animals such as monkeys, but also allowing fig wasps to reproduce wolves in Yellowstone affect elk populations, which affects tree numbers, which affects beavers, etc.
Cnidaria: cnidocytes (define subparts: trigger, nematocyst) How should you treat a sting?
A unique cell to the cnidarians, present in tentacles. Has triggers which are touch-sensitive; when triggers are activated, they release a nematocyst (essentially a bag full of venom and a stinger). neurotoxic venom made up of enzymes; some say you should treat sting with ice and some say you should treat it with hot water (slow down enzyme activity vs denature enzymes) ... hot water is probably most effective though
Annelids: advantages of metamerism?
A unique form of locomotion due to each segment having its own set of muscles lessens injury to the organism specialization of different parts of the body
What are the two acoelomate phyla?
Acoela and Platyhelminthes (flatworms)
How are amphibians adapted for terrestrial life? How are they still dependent on aquatic habitats?
Adapted for terrestrial life: -true foot - wrist bones strong enough to support the body on land -choanae: nostrils connected to pharynx (amphibians can breathe through their nostrils, unlike sharks & fishes) -vertebral column strengthened for support out of water Dependent on aquatic habitats in other ways: -cutaneous respiration (breathing through skin) means that skin must stay moist -3 respiratory organs = skin, lungs, gills (all for gas exchange) -reproduction and development: *eggs need to develop in water (eggs are fishlike) *metamorphosis (maybe this is what "amphi" + "bio" refers to?)
Coelomate
An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm).
Pseudocoelomate
An animal with a body cavity only partially lined by tissue derived from the mesoderm the cavity is between the mesoderm and the endoderm rather than within the mesoderm
autotrophic
An organism capable of synthesizing its own food from inorganic substances, using light or chemical energy. (photosynthesis OR another process.) Green plants, algae, and certain bacteria are autotrophs.
producer
An organism that makes its own food
consumer
An organism that obtains energy by feeding on other organisms
What are flowers?
Angiosperm structure that's specialized for sexual reproduction (same function as a strobilus)
Gymnosperms vs. Angiosperms: how did each of the differences between the groups give Angiosperms an advantage over Gymnosperms? These advantages resulted in: 1. The Angiosperms' dominance on earth in terms of land covered 2. The Angiosperms' extensive evolutionary diversification (=speciation), with them having the greatest species diversity (=number of species) among plant groups on earth today
Angiosperms show these advantages: 1. sporangia borne in flowers (vs cones) with close interaction with animals in pollination (more directed pollen transport; diversification in response to animals) 2. increasingly rapid sexual reproduction (pollination-to-fertilization-to-seed development), with consequently shorter generation time (allows plants to grow in more seasonal environments; faster speciation) 3. seeds enclosed in ovary (which becomes a fruit), with potential for close interactions with animals in fruit/seed dispersal (fruit can protect seeds during dispersal, animals can help disperse seeds via eating fruit, etc.) 4. development of herbaceous annual habit: germination --> growth --> pollination --> seed production happens within one season, allowing angiosperms to live in temporary (seasonal) habitats. --Gymnosperms are all woody --shorter life cycle allows for faster speciation 5. vessel elements in xylem: greater water conduction than tracheids, allowing plants to live in more seasonal and varied habitats --Angiosperms have tracheids and vessel elements, Gymnosperms only have tracheids 6. reduction in size of gametophyte (Gymnosperm gametophytes can be thousands of cells, while in Angiosperms they're only 8 cells). This represents an overall evolutionary trajectory toward diploid dominant, because haploid multicellular forms are more delicate. 7. double fertilization: biparental food reserves in seed. I think this results in more genetic variation?
What nutrients are most affected by leaching? Be able to clearly explain why.
Anionic macronutrients: N (NO2-, NO3- ) + P (H2PO4-) because they're anionic, they're repelled by the negatively charged soil particles and are forced to be dissolved in the water instead. Cationic macronutrients: potassium. H+ > Ca++ > Mg++ > NH4+ > K+ represents strongest --> weakest attraction to soil particles
variety of reproductive strategies in Anura (frogs and toads)
Ascaphus (WA state): intromittent organ -"tailed frog," but the tail is actually an intromittent organ in males for internal fertilization -live in fast-moving stream --> internal fertilization allows eggs to not be swept away Rheobatrachus, Gastric-brooding frog: -Australia -external fertilization, then female swallows egg --> offspring develop in stomach -medical question: how does female shut off stomach acid production? -pesticides, etc. --> extinction of frog by 1990s Pipa pipa, Surinam toad: -looks like it's been run over (flat; blends in with leaf litter at bottom of Amazon River tributaries) -external fertilization, then male puts eggs on female's back and her skin grows over them --> eventually, metamorphosed toads burst out Oophis pumilio: -rainforests of Central America -pushes limits of the definition of amphibians due to its terrestrial reproduction -both parents care for eggs deposited in bromeliads -placing fertilized eggs in bromeliads allows them to avoid being eaten by predators, but it also means they don't have readily available food -male carries eggs on back, places them in bromeliads, brings females back with him so she can lay unfertilized eggs for them to eat
Ascomycota sexual reproduction: what is an ascus, ascocarp? How many spores are produced in one ascus?
Ascocarp = sexual body, which forms ascus at the hyphal tip Inside the ascus, a single diploid cell produces 8 ascospores via meiosis and then mitosis.
Classes within Phylum Echinodermata
Asteroidea (sea stars), Ophiuroidea (Brittle stars), Echinoidea (Sea urchins, sand dollars), Crinoidea (Sea lilies, feather stars), Holothuroidea (Sea cucumbers)
order of evolution of the domains
Bacteria, Archaea, Eukarya
three domains
Bacteria, Archaea, Eukarya
The successive plant phyla show progressive adaptations to terrestrial habitats: describe these trends.
Being vascular allows plants to grow taller, support themselves outside buoyant water environment, and transport nutrients throughout their bodies. Early plants needed to be submerged in water to reproduce, which means they couldn't be entirely terrestrial. Spores went from being transported abiotically (via wind) to biotically (symbioses with animals). The advent of seeds allows survival of whole plant as dormant embryo (vs. single cell in spore), protection and complex control of germination by parental seed coat, energy reserves for the embryo, transport to new environments by animals.
Birds are "living" _____.
Birds are living saurischian dinosaurs, but have a pubis bone that appears convergent on ornithischian dinosaurs
Why were Acoela originally considered part of the Platyhelminthes, and why did this thinking change?
Both phyla are Acoelomates, so scientists originally grouped them together. Later, molecular evidence suggested that Acoela should be a separate phylum.
setae
Bristle-like structures (hairs) that help segmented worms move
differences between butterflies and moths: -sleep patterns (nocturnal or diurnal) -coloration -antennae -form when at rest
Butterflies: usually diurnal, brightly colored, slender and filamentous antennae, at rest fold wings together above their back Moths: usually nocturnal, plain grey or white or black (subdued coloration), comb-like and feathery antennae, at rest wings are spread open
subphyla of arthropods
Crustacea, Trilobitomorpha, Chelicerata, Myriapoda, Hexapoda
Examples of some of the Phyla within the Gymnosperms?
Cycads, Gnetophytes, Ginkgo, Conifers
sessile
Describes an organism that remains attached to a surface for its entire life and does not move (eg sponges)
Earliest amphibians: when did vertebrates first venture onto land? Example of one of the earliest amphibians?
Devonian period (approx 300 mya) example: Eryops (I have a separate slide on this)
How do tapeworms reproduce?
Each proglottid contains both male and female reproductive structures (monoecious). They're fertilized via another proglottid on the same worm or via a different worm. The proglottid is then a sac of fertilized eggs which breaks off of the tapeworm. This sac is expelled with the host feces, and a new host can ingest the eggs through contaminated food, water, etc.
What is the difference between endomycorrhizae (arbuscular mycorrhizae) and ectomycorrhizae?
Ectomycorrhizae: -fungi always stay outside of plant cells -especially in trees (one tree may have multiple fungi occupying various parts of the root system) -Basidiomycota and Ascomycota -mantle (fungal sheath) on outside of root -not a lot of host specificity, but there are preferences Endomycorrhizae: -Glomeromycota -arbuscular: form little "trees" INSIDE root cells occur in nearly all plants, whereas Ectomycorrhizae are mainly in trees
What kinds of fungi are involved in endomycorrhizae (arbuscular mycorrhizae) and ectomycorrhizae?
Endomycorrhizae (arbuscular mycorrhizae): Glomeromycota Ectomycorrhizae: Basidiomycota and Ascomycota
trophic (energy) pyramids: How is energy transferred from one trophic level to another? What is the relationship in the energy contained in each successive level, and what determines it?
Energy transferred via an organism of one level eating the organism(s) of the level below it. Each successive level represents only 10% of the energy of the previous level. This is because not all organisms are consumed (structural/mechanical defenses eg thick cell walls or spikes or hairs, chemical deterrents/toxins) and tome energy goes toward excretion, respiration, etc. In mature animals food goes toward maintenance, not increasing biomass.
Old idea about nearest relatives of chordates: Chordates are flipped over arthropods. Evidence for? Evidence against?
Evidence for: -dorsal nerve cord in chordates, ventral solid nerve cord in arthropods -both have similar gut/digestive tract -metameric body plan (chordates: myotomes) Evidence against: -chordates = deuterostomes, annelids/arthropods = protostomes -DNA evidence
How do the terms hermaphroditic, monoecious, and dioecious apply to angiosperms?
Flowers are typically hermaphroditic (monoecious) but can sometimes be unisexual. They're NOT both sexes at once, though. They always have both sets of organs but they go through male and female phases (corresponds to which organs are active) in order to avoid self-pollination.
examples of Scyphozoa
Fried egg jellyfish Lion's mane jelly aka Cynaea capillata (very large; long tentacles)
kingdoms within Eukarya?
Fungi, Plantae, Animalia plus Protista (heterogenous multi-kingdom group)
karyogamy
Fusion of two haploid nuclei to form a diploid nucleus
Orders of Lissamphibia (living amphibians) that we studied
Gymnophiona (= "naked snake"): Caecilians Urodela: newts and salamanders Anura: frogs and toads
Where did the turtle body plan come from, evolutionarily? -initial study of the fossil record -study of development of turtle embryo -new discoveries in fossil record
Help from the fossil record: -Proganochelys = famous turtle fossil (looks like modern turtle, so not super helpful in figuring out the evolutionary process for today's turtle body plan) Help from developmental biology: -carapacial ridge in embryo: ribs grow outward and become carapace -plastron develops in embryo before carapace A new fossil: Odontochelys ("odonto" = "teeth," "chelys" = "turtle") -about 10 million years older than Proganochelys -turtle ancestor with teeth! (no beak yet) -plastron but no carapace --> shows that plastron evolved first (consistent with development of turtle embryo)
Examples of studies that address the ecosystem level
Hubbard Brook experimental forest: clear-cut a forest --> how do soil nutrients differ? Looking at nitrate in water runoff MORE?
Classes of Cnidarians
Hydrozoa, Scyphozoa, Cubozoa, Anthozoa
IR (ingestion ratio)
IR = (prey width)/(predator's head width) A snake swallowing something wider than its head would have an IR greater than 1. a bigger IR requires a bigger gape (comes down to the size of the quadrate bone)
prevalence of marsupials vs. eutherians in Australia How does this represent convergent evolution when compared to other continents?
In Australia all mammals are marsupials (except a few introduced eutherian species). Marsupials occupy all mammalian niches, representing convergent evolution to eutherians of other continents.
tagmatization
In a metameric organism: specialization of segments to perform different functions
Cystercosis
Infection of the brain, muscles, and other tissues by Taenia solium (pork tapeworm) larvae. Humans become the intermediate host instead of the definitive host (possible with pork tapeworm but not beef tapeworm because humans are more physiologically similar to pigs). Ingestion of eggs (for example, from accidentally eating contaminated fecal matter) causes cysts in the brain, muscles, and other tissues. These cysts can cause epileptic seizures. This is essentially the end of the life cycle for the tapeworm, unless someone is a cannibal, but it's hugely problematic for the infected human.
difference between insect wings and vertebrate wings
Insect wings evolved from outpocketing of the exoskeleton, rather than from front limbs as they did in vertebrates (insects didn't lose a pair of limbs when they gained wings) Vertebrate wings evolved later and different types of wings evolved separately without being homologous. (eg: birds have a wing membrane with feathers, bats have wings between webbed fingers, pterosaurs have a wing membrane attached to a super long pinky finger) Vertebrate wings are homologous as adaptations of front limbs, however.
Auxin: what is it? How does it function in apical dominance and phototropism?
It was the first hormone identified in plants. Apical dominance = dominance of actively growing bud over axillary buds: -auxin produced in apical bud, inhibits axillary bud growth and branching Phototropism: growth patterns of organism in response to light (plants = positive phototropism) -light receptors in apical meristems detect light (especially blue light) --> stimulates auxin to flow from meristem down shaded sides --> causes those cells to elongate more (in elongation zone) --> axis bends toward light
difficulties in application of biological species concept
It's hard to study species because of the "freely in nature" part. Also, some species can hybridize successfully? eg grolar bear
Why did venomousness evolve in snakes?
Myocene period: advent of grassland habitats meant that snakes needed to be smaller and more agile --> needed to protect themselves
Ecdysozoa (what phyla are included?)
Nematoda and Arthropoda, aka animals that molt a non-living cuticle
composition of air
Nitrogen 78%, Oxygen 21%, Other Gases 1%(carbon dioxide & water vapor, etc.)
What are the three main components of commercial fertilizer? Why is each component a limiting resource to plants? Be able to explain the situation for each of the three nutrients.
Nitrogen: makes up 78% of air but plants can't fix it into a form they can use for amino acids and other biological molecules Phosphorus: not naturally present in large quantities in the soil Potassium: doesn't stay in the soil well, also WHAT??
four phyla/divisions of plants
Nonseed: Bryophytes, Ferns & Allies Seed: Gymnosperms, Angiosperms
heterotrophic
Organisms that obtain their nutrients or food from consuming other organisms.
Can we distinguish species in prokaryotes?
Not really, because all of our species definitions rely on the presence of sexual reproduction. We can classify them in groups, though, based on various properties including cell shape, reactions to stains, appearance in colonies, pigmentation, metabolic biochemistry, and whether or not they need or tolerations free oxygen.
How does the protostome vs. deuterostome division relate to phylogenies (older phylogenies vs. the current hypothesis)?
Older phylogenies were based on protostome vs. deuterostome (see powerpoint for an example), now not so much Brachiopoda and Ectoprocta used to be classified under deuterostomes, but now they're in clade Lophotrochozoa (thought to be more like protostomes).
Classes within Phylum Annelida (segmented worms)
Oligochaeta, Polychaeta, Hirudinea ("leeches")
What orders are in clade Laurasiatheria? (ie what types of animals - just memorize their common names)
Perissodactyla ("odd-toed ungulates": horses, zebras, tapirs, rhinoceroses) -horses and zebras have 1 digit per limb; tapirs and rhinos have 3 digits per limb -horse evolved from ancestors with a larger, odd number of digits, and its nearest relatives have 3 digits Centariodactyla ("even-toed ungulates": sheep, pigs, cattle, deer, giraffes) -eg: cows have 2 toes per limb, hippos have 4 Cetaceans (whales and dolphins) -Whales and dolphins represent even-toed ungulates that evolved to live in the sea and no longer have any toes at all. Chiroptera (bats: megabats and microbats) -see other slide for difference between megabats and microbats Eulipotyphyla (moles, shrews) -insectivores --> have lines of evenly-sized teeth (compare to rodents) -examples: shrews (small but brave, often mildly venomous); solenodon (venomous, lives in Caribbean) Carnivora (dogs, cats, bears, wolves, walruses) -domestic dogs are so diverse! -domestic cats not as diverse (maybe drawn from a smaller ancestral gene pool)
Example of Class Turbellaria? -nervous system -digestive system How does it move? How does it eat? What can it sense?
Planaria -front vs. back ends (nervous system concentrated at front) -nervous system: 2 lateral nerve cords w/ transverse nerves connecting them -intestine (branches to all parts of body) -moves via cilia on underside of body; glands produce slime that Planaria glides on -eats via the one opening in its body, the pharynx, which leads to its mouth. Then the digestive system distributes nutrients throughout the body. -eyespots allow it to sense light and dark
classes of molluscs that we learned about?
Polyplacophora ("many plates") Gastropoda ("stomach foot") Bivalvia ("two valves") Cephalopoda ("head foot")
examples of Hydrozoa
Portuguese man of war (float above water; large colony of polyps & medusas --> no visually obvious symmetry, but individuals polyps/medusas are symmetrical) Hydra: freshwater, polyp form, sexual and asexual reproduction, tiny body with no anus
What orders are in clade Afrotheria? (ie what types of animals - just memorize their common names)
Proboscidea (elephants) -exist today in Africa and India Sirenia (manatees, dugongs) -originated in Africa, then diversified in the Atlantic Ocean (manatees in the Americas) and the Indian Ocean (dugongs in Southern Asia, Australia, etc.) Tubulidentata (aardvarks) -eat ants and termites Hyracoidea (hyraxes) -size of a gopher/groundhog -small, abundant and nocturnal --> hard to study -often act as a reservoir for diseases that affect other Afrotheres, for example elephants
Are snakes aggressive? Why do they bite humans?
Snakes are never aggressive. Bites to humans are due to self-defense or a misunderstanding between the snake and the human.
What are fruits? What part of the flower do they develop from?
Seeds surrounded by sweet flesh with the purpose of seed dispersal (often via animals eating them). They develop from ovaries. ADD MORE?
main organs in flowers? Roles of each organ?
Sepals and petals are sterile, stamens and pistils are fertile. sepals: enclose the flower before it opens (think rosebud) --modified leaves petals: showy (shapes/colors), often heavily scented. can help attract pollinators --modified leaves stamens: male fertile leaves with pollen sac = anther (sporangium) at tip --the filament is a modified leaf pistils (carpels): female leaves (enclosed chamber with ovule, etc) --at top: stigma (female receptive site) --style: tube that the pollen travels down --the ovary becomes the fruit
fungi: how do asexual and sexual reproduction differ, and when does each occur?
Sexual reproduction: hyphae of two mating types fuse, forming heterokaryotic mycelium (sexual body). Eventually, nuclei fuse in sexual cells (in sexual body), forming a diploid zygote. This zygote undergoes meiosis, producing spores. Asexual reproduction: occurs in certain fungal species or when environmental conditions are favorable. mycelium --> spore-producing structures via mitosis --> spores --> germination --> mycelium
body structure, life cycle, reproduction of Bryophytes
Small body with rhizoids but no true roots. Primitive stomata. Need wet habitat for growth at all times. Gametophyte-dominant. sporophyte dependent on gametophyte.
evaporation
The change of a substance from a liquid to a gas. Evaporation through the waxy cuticle accounts for less than 1% of a vascular plant's water loss.
evapotranspiration
The combined amount of evaporation and transpiration
life cycle
The generation-to-generation sequence of stages in the reproductive history of an organism shows N and 2N phases
transpirational pull
The movement of water out of the leaf "pulls" water upward through the vascular system all the way from the roots
Lepidosaurs
The reptilian group that includes lizards, snakes, and two species of New Zealand animals called tuataras. (Squamata and Rhynchocephalia)
fungi dispersal units: when, where and how are spores produced?
The sexual body consists of heterokaryotic cells. Spore-producing cells of this sexual body are in locations that are favorable for the wind to pick up spores. In these cells, the nuclei fuse to form a diploid zygote. This zygote then undergoes meiosis, producing spores.
How do xylem transport water upward, from the soil to the plant to the air?
The water starts in the roots and moves upward via transpiration, cohesion and adhesion. Transpiration at the leaves pulls the water upward because H-bonds in the water make it stick to itself (cohesion). The water also sticks to the cell walls of the xylem (adhesion) - also H-bonding. This also has to do with water potential and osmotic pressure and stuff, but I don't think we have to know that much detail.
What are the 4 main clades of eutherians? These groupings are based on what type of evidence?
These groupings are based on DNA evidence rather than morphology, therefore they don't correspond with distinct synapomorphies. 4 main clades: -Afrotheres -Xenarthrans -Euarchontoglires -Laurasiatheres
What's so distinctive about rodent teeth?
They have big, continuously growing incisors. The incisors have a gap behind them, then molars/premolars. The incisors are made of enamel and dentin, just like all vertebrate teeth. Unlike humans, though, rodents only have enamel on the fronts of their incisors. As they chew, the dentin in the teeth wears down faster than the front enamel, meaning their incisors always stay sharp.
How do guard cells function?
They have thicker cell walls facing the opening of the stomata. This means that when they take in water they "buckle," creating an opening through which gas can be exchanged. Regulated by: -water content of plant (more water means guard cells are more turgid, allowing stomata to lose more water) -proton pump: K+ ions actively transported into cell when guard cells detect daylight. Water comes with the K+ to maintain osmotic pressure, causing stomata to open and allow gas exchange for photosynthesis and respiration. positive pressure flow
When studying chordates, why is it also helpful to study Phylum Echinodermata and Phylum Hemichordata?
They're not ancestors of the chordates, but they branched off in the phylogeny earlier than chordates, so they kinda function like living evidence of our ancestry.
Classes within Phylum Platyhelminthes (flatworms)?
Turbellaria, Monogenea, Trematoda (flukes), Cestoda (tapeworms)
Miller-Urey experiment
Two scientists attempted to reproduce the condition of the (assumed) earth's primitive ocean's under a reducing atmosphere. Added energy input from electrodes. They produced some of the key molecules to life (amino acids and nucleotides).
"re-discovery" of the coelacanth
Until the 1930s, they were only known from fossils and people thought they were extinct. Marjorie Latimer was a trained nurse who worked in a museum in South Africa and enjoyed reading about natural history. She "re-discovered" the fish when she found and bought one at a fish market. Since then, others have been found, but not super often since it's a deep-sea fish that doesn't come in contact with humans super frequently.
Two main types of venom and their corresponding snake families?
Viper family (vipers, rattlesnakes, etc.): hemotoxic venom Cobra family (cobras, coral snakes, etc.): neurotoxic venom I have separate slides for each of these venom types.
WR (weight ratio)
WR = (prey mass)/(predator mass) Weight ratios over 1 are actually fairly common - the record is a Viperid that had a WR of 1.72, but that snake burst open.
Why are amphibian species declining so much? Why amphibians instead of other vertebrates? Why should we care?
Why decline? -pesticides/pollution -introduced species -commercial exploitation -increased exposure to UV light -Chytrid (emerging disease - skin fungus that specifically affects amphibians) *spreads in part due to the export of African frogs for use in labs -habitat loss (esp. destruction of wetlands/breeding sites) Why amphibians? -we don't know -maybe because of two-part lifestyle (vulnerable to changes in water AND on land) Why should we care? -amphibians are the canary in the coal mine
How do animal-pollinated flowers differ from wind-pollinated ones?
Wind-pollinated plants have: -reduced petals -no nectar -smooth, dry pollen grains (light, aerodynamic, don't stick to each other) -typically little scent (some have scents for defense) -big sexual organs (so they're caught by wind) -flowers often in catkins (clusters of flowers hanging down)
How do fruits adapted to dispersal by animals differ from wind-dispersed ones?
Wind-pollinated plants have: -reduced petals -no nectar-smooth, dry pollen grains (light, aerodynamic, don't stick to each other) -typically little scent (some have scents for defense) -big sexual organs (so they're caught by wind) -flowers often in catkins (clusters of flowers hanging down) Showy flower parts are a hindrance and are unnecessary
Do prokaryotes carry out photosynthesis and cellular respiration? If so, where do they occur?
Yes. Both in cell membrane infoldings
polytomy (what does it look like and what does it represent?)
a branch point from which more than two descendant groups emerge illustrates that scientists aren't really sure what the evolutionary relationships among that clade are
Lophotrochozoa
a clade characterized by having a lophophore feeding structure and/or trochophore larvae
branch of phylogenetic tree
a line representing a population through time On the phylogenetic tree showing all animals, each branch represents one animal phylum.
What are reptiles? (ie what lineages does the classification include? Is it a clade?)
a paraphyletic group equivalent to amniotes but excluding mammals and sometimes birds see powerpoint for a really good phylogenetic diagram
allopatric speciation (examples?)
a population forms a new species while geographically isolated from parent population eg squirrels on two sides of a canyon or small rodents on two sides of a river
synapomorphy
a shared, derived character eg, the presence of mammary glands is a synapomorphy for mammals in relation to tetrapods
When did animals and fungi first appear?
about 800 million years ago (0.8 bya) People disagree on the timeline, though.
capitalization, italics, underlining of species name?
always capitalize genus, never capitalize specific epithet binomial italicized (in type) or underlined (when handwritten) author: initial caps, but not italicized or underlined In a paper, spell out the genus once, then abbreviate: eg Rosa canina --> R. canina
What shape is nematode sperm? Why?
amoeboid - maybe this shape is more effective at moving through the female reproductive cavity against the pseudocoel's hydrostatic pressure?
"typical" frog life cycle How do frogs reproduce?
amplexus = frog mating strategy: -mating in water -males are smaller than females -male sits on top of female, grasping her with his front legs -female lays eggs, male sprays them with sperm (external fertilization --> more care by both parents) frog metamorphosis: fertilized egg --> legless tadpole --> hind legs --> front legs --> adult
superorganism
an organism consisting of many individuals, such as an ant colony or beehive, in which individuals cannot survive independently
skull fenestration in turtles
anapsid skull is thought to be secondarily derived from diapsid ancestors
what is recent geological history based on?
animal fossils
Distribution of species among kingdoms; which is the largest kingdom?
animal kingdom has the most species (diverse and specialized feeding causes speciation; larger animals are also easier to study than tiny organisms)
general characteristics of sponges (phylum Porifera)? symmetry body shape/form and mobility interaction with environment/water direction of water flow
animals (multicellular) 5,000 species asymmetrical sessile, porous body with choanocytes water flow through body --> uptake of food particles, O2, other sponges' gametes; release of gametes water flows in through pores and out through osculum
Where would you expect to find deuteromycota/Fungi Imperfecti?
any place where there's mold? often moldy food has lots of penicillium
morphological species concept (why is this more commonly applied in describing/defining a species?)
based on appearance or structure of an organism (heavily based on sexual organs, which don't vary with habitat) More commonly applied because it's easy to study morphology in nature and in the lab. It's often the first thing we notice when looking at un unknown organism.
How do we classify fungi into different phyla?
based on structure of zygotic 2N cell = diploid cell formed inside sexual body when nuclei in a heterokaryotic cell fuse
Basidiomycota sexual reproduction: what is a basidium, basidiocarp? How many spores are in one basidium?
basidium formed inside a basidiocarp (which = whole sexual body), produces basidiospores 4 haploid spores produced via meiosis in one diploid cell (at hyphal tip)
What was the earliest ancestor of the chordates like? What were its ancestors like?
before chordates: huge diversity in animal body plans in Cambrian period ~530 mya -almost look alien Myllokunmingia = earliest chordate ancestor: -very small animal -distinctly chordate features: myotomes (muscle segments - think of meat separating when you eat salmon), notochord, distinct anterior and posterior ends -the picture is an illustration of what Myllokunmingia probably looked like (reconstructed from fossils)
What is a biome? How do they relate to our descriptions of global patterns in the biotic landscape?
biome = broadest category of ecosystem, defined by producers (vegetation) Global patterns in the biotic landscape are described in terms of biomes.
four major groups of factors that influence change in population size over time
birth and immigration (recruitment), death and emigration (removal)
coelom (what animal groups does this term apply to?)
body cavity lined with mesoderm (within mesoderm tissue layer) - between digestive cavity and outer body wall ONLY applies to triploblastic animals
fungi body structure? (what does the term "mold" refer to?) specialized body structure for parasitic and predatory fungi?
body composed of thread-like, single series of cells called hyphae, which form an interconnected network = mycelium (exception: some yeasts are unicellular) Hyphae may be septate (cells separated by plasma membrane and cell wall, aka septum, which has a large pore) or coenocytic (no separated cells; karyokinesis occurs without cytokinesis and only nuclei divide; cytoplasm = continuous). More primitive forms of fungi are coenocytic. Parasitic fungi have specialized haustorial hyphae for feeding on live cells, predatory fungi have specialized hyphae for catching prey "Mold" is the whole body/mucelium
Osteichthyes -diversity -general morphological characteristics
bony fishes diversity: -there are about 61,000 species of chordates, and about 60,000 of them are bony fishes -humans are technically bony fish (because our arms & legs evolved from lobe fins) general characteristics: -bony internal skeleton (as opposed to cartilaginous skeletons eg. in sharks) -lungs, or modifications of lungs (eg. our lungs vs. swim bladders) -special type of skin (I have another slide for this)
structure of arthropod exoskeleton (layers)
bottom layer = hypodermis (cells soft & fully fleshed out) middle layer = procuticle (composed of a less hardened layer with a more hardened, pigmented layer outside of it) outside (top) layer = epicuticle (hardest layer) basement membrane is between the body and the cuticle setae extend through exoskeleton tracheae (openings) --> gas exchange
examples of Cubozoa
box jellies ...??? HELP
How to remove a bloodsucking leech
break suction with fingernail or other hard, thin object
Terrestrial salamanders without lungs: how do they manage?
breathe through skin - OK because they're so small (favorable surface area-to-volume ratio)
stages of a snake eating another snake
capture (strike with jaws) killing (coil around other snake --> hold on with jaw and try to cut off blood supply in neck. This can take almost 8 hours) swallowing (can take 90 mins and often ends in regurgitation) digesting All these steps have an energy cost, so the energy gain from the prey has to be worth it
How can mineral nutrients be "stored" in the soil and hence protected from leaching?
cations are attracted to negatively-charged soil particles
Wuchereria bancrofti characteristics
causes filariasis (name of the infection). Filariasis has its own slide.
what is mitosis and when do eukaryotes use it?
cell division that produces two daughter cells identical to parent cell. Used in growth and asexual reproduction.
Why did scientists previously classify all life into plant vs. animal?
cell wall (fungi used to be considered plants - illustrates how dynamic biology is)
sponges: porocytes
cells lining pores "cyte" = "cell"
marsupials vs. eutherians: reproduction
differences in placentas: -marsupial embryos have a vestigial allantois and a big yolk sac; placenta is made from yolk sac & chorion ("yolk sac placenta") -eutherian embryos have a vestigial yolk sac; placenta is made from chorion & allantois ("chorioallantoic placenta"). The yolk sac is vestigial, but the placenta allows food to come from the mom's blood. (see powerpoint for a comparison of the embryos) gestation vs. lactation: -marsupials = shorter gestation, longer lactation (babies born at an early stage, move to the pouch to continue development while suckling from nipple) -eutherians = longer gestation, shorter lactation
diploid dominant (which multicellular kingdom?)
diploid phase is multicellular and lasts a long time mitosis in diploid phase gametes are unicellular Animal kingdom
ecological succession (primary and secondary)
directional change in the species composition of a community over time, initiated by a disturbance to the community primary: disturbance remoces soil --> bare rock (lichens are initial colonizers) secondary: disturbance removes all life above soil (animals and plants in soil survive)
Trichinellosis
disease caused by Trichinella spiralis causes digestive distress, muscle pain, fever, etc. (I don't think we actually have to know the symptoms)
In what form are macro- and micronutrients present in the soil?
dissolved in water in the soil (nutrients are charged ions that are attracted to polar water molecules) also can be attracted to soil particles, which helps them stay in the soil
hierarchical groups (kingdom, etc)
domain kingdom phylum class order family genus species (remember: Damn, Kinky People Can Often Find Great Sex)
Arthropod metamorphosis (what is it and why is it advantageous?)
drastic morphological change from larvae to adult ("meta" = "big," "morphosis" = "change of shape") eg caterpillar (eats leaves) --> butterfly (feeds on nectar) young stage is called "larva" because it's morphologically different from the adult. In contrast, the young of mammals are called "juvenile" because they essentially look like small adults advantages: no competition between larvae and adults (different feeding patterns; occupy different ecological niches)
What is coral?
dried, remaining skeleton of Anthozoa Anthozoa deposit layers of calcium carbonate at the base of the polyp...these layers build up over lots of time...coral reefs form (each layer is one lifetime of a polyp)
What is the significance of mycorrhizae in terms of plant evolution?
early plant fossils show evidence of mycorrhizae - many plant/fungi pairs probably evolved together
global ecology
ecology at the level of the whole planet
ectothermy vs. endothermy in mammals
ectothermy = cold-blooded endothermy = warm-blooded
Myriapoda: examples and characteristics
eg. centipedes and millipedes -body divided into head and trunk -uniramous appendages -centipedes: 1 pair of appendages per body segment -millipedes: 2 pairs of appendages per body segment -centipedes are venomous, millipedes are poisonous (some species)
Class Polyplacophora ("many plates"): example? general characteristics? -habitat -morphology -how does it move and what does it eat?
eg. chitons -marine -shell with 8 plates -foot for locomotion -radula -no head -most closely resembles generalized body plan -mantle under shell -gills -moves in anterior direction, scraping off & eating algae as it moves
Class Bivalvia ("two valves"): examples? (generally + a specific species?) general characteristics? -habitat -movement patterns -symmetry -morphology -feeding patterns -other features
eg. clams, scallops, mussels, oysters -marine or freshwater -sessile -bilaterally symmetrical -"two valves:" valves = shells -flattened shell -still has muscular foot between 2 shells -adductor muscles hold animal shut -hinge point of cell = umbo -paired gills (for gas exchange and food particle collection) -suspension feeders (feed on material suspended in water. they collect food and transfer it to cilia on edges of gills, which pass the food to the mouth) -filter feeders are especially vulnerable to pollution because they collect pollutants in their bodies -mantle forms siphons (pearls) shipworms: -shell/valve reduced, body large -shell = scraping/cutting tool --> makes hole that it lives in -hole provides protection for body -can drill into wood, concrete, etc. --> lots of harm to shipping industry
Crustacea: examples and characteristics -habitat -distinct morphological characteristics
eg. lobsters, crayfish, crabs, shrimp, barnacles (sessile crustacean), copepods more specific examples: hermit crabs, copepods, isopod crustaceans ("roly-poly") -mostly marine or aquatic -biramous appendages (2 branches at the tip of each appendage, eg 2 pincers) -animal species with the largest number of individuals: a species of copepod
Class Gastropoda ("stomach foot"): examples? (generally + a specific species?) general characteristics? -habitat -symmetry -morphology
eg. snails, slugs -"stomach foot" because it looks like it's walking on its stomach -marine, freshwater or terrestrial -Secondarily asymmetrical: minus shell, snails are bilaterally symmetrical. Ancestral snails were totally bilaterally symmetrical (including their shells). Larvae are bilaterally symmetrical, mantle & shell & visceral mass twist as they develop (torsion). This is enough that we can still call Gastropoda part of Bilateria. Body plan: -look at lab manual p. 72 for a really good diagram (also in the powerpoint)! -muscular foot -mantle under shell -visceral mass (including intestine) coiled within shell snail example: cone snail (Conus geographus) -cone shell -venomous barb used in prey hunting
Chelicerata: examples and characteristics
eg. spiders, scorpions, ticks, mites, daddy-long-legs, horseshoe crab, etc. -body divided into two parts (cephalothorax and abdomen) -no antennae -1st pair of appendages used for feeding -four pairs of uniramous walking legs (contrast with crustaceans' biramous appendages)
Class Cephalopoda ("head foot"): examples? (generally + a specific species?) general characteristics? -habitat -feeding habits -morphology
eg. squid, octopus, nautilus -marine -predators (top ocean predators before evolution of the jaw) -rich fossil history -head surrounded by grasping tentacles -locomotion by jet propulsion using siphon (aka funnel; made from foot) -ink sac for escape -eyes convergent on vertebrate eye squid anatomy: -funnel, head, arms from muscular foot -no shell, but mantle under where shell would be -mouth w/radula, bird-like beak -pen = stiff rod of chitin-like material (gives squid shape & stiffness) Giant Squid: deep-sea animal, but occasionally dead ones wash up on shore --> can be studied
layers of mammalian skin
epidermis, dermis, subcutaneous layer stratum corneum is the outermost layer, but I'm not sure if we need to know that. The powerpoint has a good diagram of the layers.
adaptive evolution
evolution that results in the population being better adapted to its environment
transpiration
exhalation of water vapor through the stomata
How does leaching and fertilizers tie in with dead zones in the Gulf of Mexico?
fertilization of crops in central states in Mississippi drainage basin --> N, P, K leach into ground water, streams, and then Mississippi River --> flow into Gulf of Mexico increased nutrient levels in Gulf means more aquatic producer life...and death...and decomposition (requires cellular respiration) This all leads to lower levels of O2 --> "hypoxic" dead zones with much less life
What are the consequences of leaching in terms of the nutrient content of the soil?
fewer nutrients in the soil
What features of the plant body are characteristic of ferns?
fiddleheads (young leaves), sporangia with annulus (hygroscopic tissue that busts the sporangium open), sori (clusters of sporangium), strobili (stalks, each with larger leaves and then smaller fertile leaves containing sporangia)
examples of convergence (homoplasy)
fins in dolphins and sharks white fur in cats and polar bears (the hair itself is homologous but the white color is convergent - in cats it's just due to individual variability)
What is lichens' role in community succession? Give an example.
first colonizers in primary succession lichen can often fix nitrogen using cyanobacteria photobionts --> use atmospheric gases to create fertile soil EXAMPLE??
General characteristics of Phylum Platyhelminthes? (symmetry? # of tissue layers? coelom status?)
flatworms ("platy" = "flat," "helminthes" = "worms") bilaterally symmetrical triploblastic, acoelomate
adaptive radiation
form of allopatric speciation, in which populations of a species establish themselves in various ecological niches and eventually form new species
speciation
formation/development of a new species (product of evolutionary change through natural selection)
What insect orders did we study?
four largest orders: Coleoptera, Hymenoptera, Diptera, Lepidoptera We also studied Siphonaptera just because it's Kate Jackson's favorite. :)
Tetrapoda
four-limbed vertebrates
Xenopus - the lab frog
from Sub-Saharan Africa used in labs for pregnancy tests (exported around the world) exported --> pests in waterways --> bring Chytrid fungus to other animals (one of the things that's responsible for the current mass extinction of amphibians)
How does phloem sap move?
from a sugar source to a sugar sink. Phloem go in all directions in the plant, as opposed to xylem which only go up. At sugar source: active uptake of sugar into sieve tube element, then water also flows into sieve-tube element (osmosis). This increases pressure in the cells, pushing the sap to a region of lower pressure, where there is active uptake of sugar into energy-storage/energy-demanding cells. When sugars flow out of sieve-tube elements, water does too (osmosis), causing a return to low pressure near the sugar sinks.
Structure and function of mammalian hair
function = insulation & sensing (Insulation traps heat that already exists, but it doesn't create heat. Therefore it only has a warming effect if the animal is warm-blooded.) structure: -extends through layers of skin -sensory-nerve endings wrapped around hair -arrector pilli muscles at base of hair allow the hair to stand on end if necessary (--> goosebumps, etc.)
Mycoses
fungal skin pathogens in humans, such as "Ring Worm" and Athlete's foot grow on skin because they need a cool environment (can't survive in our warm internal body temperature)
What are endophytic fungi?
fungi (or bacteria) living inside plants: microbiome occur all over in plant body typically invisible from outside; do not cause apparent disease
Glomeromycota characteristics
fungi that form endomycorrhizal associations with plants
What defines a lichen?
fungus + alga and/or cyanobacterium ("photobionts," light-dependent organisms). It's a composite organism!
Lichen: what is the nature of the relationship between the fungus and its photosynthetic partners?
fungus gives photobiont more access to sun, protection, minerals and water. photobiont gives fungus glucose Generally considered mutualism, but some say it should be considered parasitism - the photobiont could survive on its own but the fungus can't
Dutch Elm Disease
fungus invades vascular tissue, secretes toxins, and clogs xylem cells. Visual evidence includes the higher leaves of the tree being yellow/dead looking vector = bark beetles that lay eggs below the bark can fight the fungus by spraying trees with insecticides
How do lichen reproduce (sexually and asexually)?
fungus reproduces sexually and asexually, photobiont reproduces asexually from lab manual: "Lichens reproduce both asexually and sexually. In their asexual reproduction, they form soredia (dispersal units of fungal hyphae and algal cells) or parts of their thallus may break off as fragments that can be carried to other sites. In their sexual reproduction, they typically form ascocarps."
syngamy
fusion of two gametes, aka fertilization
gemete vs. spore
gamete = single haploid cell, destined to fuse with another cell spore = single cell (any ploidy) that will divide by mitosis
What major distinctive features are shared by the seedless plants?
gametophyte is green, free-living, non-vascular need water for fertilization in gametophyte stage - flagellated sperm haploid spores produced by sporophyte in gametangia, dispersed via wind and hygroscopic tissues typically grow in shady, cool areas can tolerate low-light conditions some can tolerate high levels of desiccation (some mosses and "resurrection" plants)
binomial system (2 parts of species name?) and what's the third component that comes after the binomial (must include the first time you mention the species)?
genus + specific epithet ("binomial" = "2 names") author: copy it exactly as you see it, including parentheses, and only use official abbreviations
examples of current problems in global ecology
global temperature patterns (climate change), changes in ozone layer
cellulose
glucose polymer ("fiber") in plant cell walls
chitin
glucose with an amino group, found in fungal cell walls
overall structure of a sponge
green arrows represent water flow
clade (monophyletic group)
group which includes a common ancestor and all descendants of that ancestor
types of extremophile archaea
halophiles (halogens: salt-loving) thermophiles (heat-loving) - source of Taq polymerase, useful for PCR methanogens (generate methane) - anaerobic, autotrophic (non-photosynthetic), decompose organic matter in wetland mud sediments and ruminants (= animals with multi-chambered stomachs that chew food multiple times)
Do mosses produce haploid or diploid spores?
haploid - spores are destined to become the gametophyte; mosses are gametophyte dominant
haploid dominant (which multicellular kingdom?)
haploid phase is multicellular mitosis in haploid phase 2n zygote fungi
fungi life cycle type
haploid-dominant
Why are insects so successful?
insects = ~90% of arthropod species! evolutionary history - early evolution of wings: -first to evolve wings (~300mya) -Permian period: different atmospheric composition allowed giant insects to exist -insects = first animals to colonize the air --> opened up a lot of habitat niches
Annelid morphology: Given that the body is metameric, most features are discontinuous. What structures pass all the way through the worm body without interruption?
intestine, nerve cord, blood vessels
Gnathostomes (Class Gnathostoma)
jawed vertebrates
Nereis sp. (ferocious marine worm): how does it move?
lateral undulation via longitudinal muscles
what groups of species are most well known? least well known?
least --> most known eukaryotes: fungi, protists, plants, animals attractive or large organisms are better known, organisms that live in difficult-to-study environments (such as soil) are less known How known an organism is is based on how much time and effort it takes to study it. Also how interesting it is to study (are people willing to spend a lot of time and money studying tiny worms?)
How has earth's atmosphere changed over recent geologic time in terms of both oxygen and CO2 content?
less CO2 in atmosphere after plants colonized land Carboniferous period: lack of O2 meant not much decomposition of plants --> fossils O2 levels gradually rose in Carboniferous period (lots of plants)
advantages of current system for naming species?
less ambiguity: standardization of format means you immediately know the genus, specific epithet and author. Having scientific names reduces confusion of using common names, which can vary based on location. Also one common name sometimes refers to several different species
amphibians: pre-adaptations to life on land
limbs with digits (fingers): -early fossils of fishes (prototetrapods) show digits, but with joints that couldn't have supported them on land -digits would've been useful for webbed fingers - swimming, etc. -period of experimentation in body plans: big variety of number of digits on each limb (we just happened to evolve from a lineage with 5) lungs
two examples of Bryophyte groups
liverworts, mosses
Looking at the current diversity of each phyla, we count the number of living and described species. What do "living" and "described" mean?
living = not extinct described = discovered by scientists and given a name Some phyla are historically very diverse but don't have many species alive today (that we know of). These counts are also impacted by how easy it is to study/discover various types of organisms, for example there are probably a LOT of nematode species out there that we just haven't discovered yet
Lissamphibia
living amphibians
Sarcopterygii
lobe-finned fishes
What is a strobilus (cone)?
location of sporangia in Gymnosperms. Sporangia are densely aggregated around a stem. "Strobilus" and "cone" are pretty much synonyms.
pharyngeal slits: location and function (early evolutionary history vs. today)?
location: pharynx function: In early evolutionary history, they were used for filter feeding. Now, they allow gas exchange in fish (gills). We have pharyngeal slits too - see the slide about humans
How does a basidiocarp develop? Identify its major parts.
look at class handout
Flatworms: what are the advantages of being flat?
lots of surface area for nutrient absorption
What group of Fungi is most common in lichens?
mainly Ascomycota (+ Basidiomycota yeast?)
rust fungi
makes stem of wheat look rusty note complex life cycle with alternate host plants: wheat and Barberry (Oregon grape)
What are pollen grains? Where are they formed? What's their function?
male sperm-carrying units for both Angiosperms and Gymnosperms. Formed in male sporangium (pollen sac/anther or on a male cone). Their function is dispersing sperm, protecting it until it reaches a compatible female stigma, injecting the sperm into the stigma
male vs. female strobilus
male strobilus = simple strobilus 2 sporangia under each leaf (exposure to air) microsporangia = pollen sacs female strobilus = compound strobilus leaves from axillary bud are fertile 2 sporangia on top of each leaf Each cone scale contains two ovules; each ovule contains a megasporangium
Synapomorphies of mammals
mammary glands and hair/fur
General characteristics of parasitic symbioses in fungi?
many involve plants, some involve animals (higher body temperature means fungi don't survive well in mammals and birds) ADD MORE
Schistosomiasis: who is affected?
many people in the global south
examples of landscape ecology
marine dead zones: fertilizers in Mississippi drainage basin --> leeching into groundwater and streams --> flow into Gulf of Mexico --> eutrophication (excessive nutrients for phytoplankton) --> decomposers use up O2 --> hypoxic dead zones (too little O2) connections/corridors between reserves: allows organisms to cross between two ecosystems (eg a bridge over a highway); zones between ecosystems where different types of organisms interact
Why do snakes eat other snakes?
maybe: maximal weight ratio with minimal ingestion ratio
Prokaryotic vs. Eukaryotic Cells
membrane-bound organelles: P no, E yes DNA: P circular, E linear size: P 1-10 μm, E 10-100 μm ribosomes: submits different in P & E
Arthropods: metamerism
metamerism modified by tagmatization (eg: especially visible on the ventral side of the crawfish, where each segment has appendages modified for a specific function.) metameres visible from outside, but no internal segmentation as in annelids (WHY?)
copepods (what are they and why are they important?)
minute shrimp-like crustaceans; often they are the most common zooplankton very ecologically important as filter-feeders The animal species with the largest number of individuals is a species of copepod.
From what bacterial groups did mitochondria and chloroplasts originate?
mitochondria from alpha-proteobacteria, chloroplasts from cyanobacteria both gram (-) bacterial groups (2 membranes)
function of various organelles?
mitochondria: respiration nucleus: contains genetic information UPDATE THIS OR JUST LOOK AT TEXTBOOK
Why are arthropods called "the most successful phylum?"
more than 1 million known species of arthropod (!!) and an estimated 30-50 million still to discover [figuring out how many there are still to discover: for example, enclose an entire rainforest tree in plastic and gas it --> examine makeup of species on it and treat that tree as generalizable] four of every 5 described animal species are arthropods (arthropods = largest animal phylum) they occupy lots of different ecological niches
Arthropods are most closely related to which other phylum? What were they previously thought to be most closely related to?
most closely related to nematodes previously thought to be most closely related to annelids, based on morphology (because both phyla are metameric). Genetic evidence revealed that arthropods are actually most closely related to nematodes.
What kinds of symbioses can endophytic fungi form with plant hosts?
mostly mutualistic symbioses, can become parasitic if plant becomes sick/weak can produce toxins (protect plants, but bad for animals that graze on the plants) can increase plant tolerance to stress: 1. insect pests 2. fungal pathogens 3. drought example: decrease impact of pathogenic Phytophthora on cacao trees
Mutualism involving fungi: is it mostly in producers or consumers?
mostly producers, but some in animals: tropical leaf-cutter ants: feed on fungus that they cultivate on leaves in their nest ("farmer ants"). They know which leaves provide best fuel for fungal growth. mutualism between fungi and producers includes lichens, mycorrhizae, endophytes (three main groups)
metazoa
multicellular animals meta = big, zoa = animals
alternation of generations (which multicellular kingdom?)
multicellular in both diploid and haploid phases: sporophyte (diploid) and gametophyte (haploid) named after what they produce plants
sources of genetic variation in populations and species
mutations: must occur in gonads (testes/ovaries) to be passed on to the next generation sexual reproduction: meiosis (independent assortment and crossing over), random fertilization
Mycorrhizae: what is the nature of the relationship between the plant and fungus?
mutualism: fungus gives plant minerals: nitrogen, phosphorous, potassium plant gives fungus glucose
What is a mycorrhiza?
mutualistic relationship between a fungus and a plant root
sister group
nearest relative of a taxon/lineage
jointed limbs in arthropods: why are they necessary and how do they work? How are the muscles attached?
necessary because the exoskeleton is inflexible, but the animal needs to bend its limbs to be mobile without some type of skeleton, muscle contraction just results in that part of the body "scrunching" extensor and flexor muscles are attached to soft folds of the procuticle that extend inside the exoskeleton muscles cross the joint so that they bend the joint when they contract
Ecdysis (molting) in arthropods: why is it necessary and how does it work?
necessary because the inflexible exoskeleton can't grow with the animal As the animal grows, it produces a new cuticle and eventually sheds the old one. A molting gel forms between the hypodermis & the old cuticle (slippery --> ensures easy shedding) -separation of old procuticle from hypodermis -new procuticle and epicuticle secreted -old exoskeleton splits when animal stretches -sclerotization (hardening of new exoskeleton)
Why are most Bryophytes restricted to wet habitats?
need water to disperse their gametes (flagellated sperm)
Compare morphological diversity of the Mollusca with that of other phyla we have studied (eg Nematoda)
nematodes aren't super morphologically diverse mollusks: snail vs octopus vs. others (much more diverse) With molluscs, the challenge is to make sense of their body plans in context of their evolutionary history and phylogeny.
Black widow spider venom
neurotoxin
What is a seed?
new sporophyte + stored nutrients + seed coat (old sporophyte). Contains two generations: parent = 2N seed coat, which determines water uptake, etc. for baby seed offspring = 2N embryo
fungi reproductive strategies
no free gametes "mating types" instead of male vs. female mating: 2 hypha tip cells (of different mating types) fuse, --> form own mycelium, keep two nuclei as separate nuclei (heterokaryotic) new mycelium forms sexual body (ONLY formed from heterokaryotic mycelium) --> inside sexual body, some cells' nuclei fuse to --> 2N zygote, which forms spores via meiosis
What is meant by "non-vascular?"
no lignified xylem
When did each phylum of plant evolve on a relative time scale?
non-vascular, non-seed (Bryophytes): 485 mya then vascular non-seed (Ferns & Allies): 400 mya then vascular seed (Gymnosperms): 360 mya then vascular seed (Angiosperms): 120 mya
spicules (two meanings related to two phyla)
nonliving, rigid component of sponge (~skeleton) also refers to a male nematode's intromittent organ
snake internal anatomy
note that the body cavity is very long with a short tail cloaca marks the end of the digestive tract
Why are chordates called chordates?
notoCHORD
What unique characteristics define a chordate? (just name them)
notochord, dorsal hollow nerve cord, pharyngeal slits, post-anal tail, endostyle I have a separate card for each of these.
synapomorphies for chordates
notochord, dorsal hollow nerve cord, post-anal tail, endostyle not pharyngeal slits, because those are a synapomorphy of all deuterostomes
macronutrients
nutrients that plants need in large quantities
micronutrients
nutrients that plants need in smaller quantities
examples of Anctinopterygii (ray-finned fishes)
occupy diverse marine and aquatic habitats, but all follow the same basic body plan (internal organs and external fin locations) -clownfish -moray eel -flounder/flatfish: lies flat in sand with two eyes facing up (eyes move to one side of body during development, so it's still part of Bilateria) -mudskipper: lives at water's surface and in mangroves; bulging eyes -coho salmon
insect vision -define ocelli, compound eyes, ommatidia -What's so special about insect vision?
ocelli = light-sensitive spots (similar to Planaria, labeled "simple eyes" in the picture) compound eyes: big eyes made of many tiny subunits (ommatidia) What's so special: -range of vision: can see almost 360 degrees! -vision at high speed - not blurry like it is for us -color vision:many can see in UV range (wavelength too small for us to see) --> locate markings on certain flowers, etc.
endostyle
on interior floor of pharynx: sticky groove that secretes mucus to trap food particles in early chordates and some of today's species: water enters through pharynx and is filtered out through pharyngeal slits; food trapped in endostyle as water flows by The endostyle is a precursor to the thyroid gland.
bilateral symmetry
one plane of symmetry that divides the organism in two
characteristics of Anthozoa
only exist as polyps build coral reefs through their calcium carbonate skeletons
types of syngamy
oogamous = 1 nonmotile gamete, 1 motile (eg humans) isogamous = 2 gametes look identical anisogamous = 1 large gamete, 1 small
Arthropods: haemocoel
open circulatory system -fluid-filled open space inside the whole body -internal organs bathed in haemolymph (in place of blood) -vessels open to hemocoel and pump fluid around -exchange of gases, nutrients, etc. is carried out by this fluid -contrast to annelids' closed circulatory system
sponges: osculum
opening where water and gametes leave
There's only one marsupial species in N. and S. America. What is it?
opossum, Didelphis virginiana
basic properties of living systems (definition of life)
order, energy processing, evolutionary adaptation, regulation, reproduction, response to environment, growth and development
model organism
organism that's studied in order to learn general principles in biology
Characteristics of Class Trematoda (flukes) example?
parasitic example: Schistosomia mansoni (Schistosomes) - causes Schistosomiasis in humans
parts of an ovule
parent sporophyte (cells on outside of the sporangium = "integument") gametophyte (egg and other haploid cells) ADD A PICTURE TO THIS?
biological species concept
populations of individuals capable of interbreeding freely in nature to produce viable, fertile offspring, but which cannot reproduce successfully with other species viable = can sexually mature fertile = can reproduce reproductive isolation from other species
types of symbiosis
predation (kills organism, including killing a plant) -, + parasitism (feeds on living organism) -, + competition -, - mutualism +, + commensalism +, 0
types of consumers
predators (kill an entire other organism) parasites (feed on a living organism) saprobes/decomposers/detrivores (feed on dead organism)
biogeochemical cycle
process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another
first molecules for life (early earth)? where did life originate?
proteins and RNA probably, spontaneous formation of organic molecules from atmosphere (Miller-Urey experiment)
Choanoflagellates
protists that are the closest living relatives of animals -unicellular organisms that live as colonies -single cells aren't considered parts of an animal because they can live on their own -similar to choanocytes of sponges
Phylum Rotifera characteristics -status of coelom -habitat
pseudocoelomate, found in pond water more info on these in the lab manual, I think
Name the two techniques snakes use to swallow large prey.
pterygoid walk, concertina swallowing
ray-finned fishes vs. lobed-finned fishes: differences in fin anatomy
ray-finned fishes: fins are made up of fin rays (skeleton and musculature do not extend into fin) lobe-finned fishes: skeleton and musculature extend into fin; precursor of legs This picture isn't great, but the powerpoint has a good comparative diagram.
How do flowers attract pollinators?
scent (olfaction) produced mostly by petals, but also by pollen color (vision) size (vision) small flowers --> inflorescence (cluster of flowers) large flowers usually single or in open inflorescence Often, flowers have specific characteristics that target certain pollinators. For example, flowers that attract birds are often red because birds can see red well, and are not scented because birds can't smell.
corn smut
scientific name: Ustilago maydis edible for humans! Considered a pathogen in the US but a delicacy in Mexico!
examples of Anthozoa
sea anemones and corals brain coral
Christmas tree worm and Feather duster worm
sedentary Polychaetes -tube worms -worm is made of sand and mucus -setae concentrated at one end and used for gas exchange (the picture is of a Christmas tree worm)
How are fruits and their seeds dispersed?
see lab materials
define and locate sporophylls (=scales) and bracts in cones
see lab materials Sporophylls = spore-producing leaves. Each has 2 sporangia above or below it (depending on sex of strobilus): above in females, below in males Sporophylls become "scales" when they become woody Bracts = leaves associated with sexual reproduction. In female cones, they're the small leaves below the sporophylls (sporophylls actually grow out of axillary buds, and the bracts are the associated leaves). Hard to spot in most cones.
Which animals have which type of skull fenestration?
see phylogeny in May 6 lecture handout - please actually quiz yourself on this
Explain how each organ of the flower consists of modified leaves
see previous slide MORE?
describe and draw the different parts of a seed and their functions
seed coat: protection endosperm: food store embryonic plant: including root axis, shoot axis, cotyledons (leaves) In many seeds the endosperm is moved into the embryo's leaves: there's no "free" endosperm tissue
metamerism (metameres)
segmented body (segments = metameres)
What characteristics do Ascomycota and Basidiomycota share?
septate hyphae, macroscopic sexual bodies
How do nematodes reproduce?
sexually by internal fertilization each worm is either male or female (dioecious)
ecosystem ecology
sum of biotic and abiotic interactions involving all species that live in the same location (eg interplay btwn abiotic and biotic in succession)
ecological niche
sum total of abiotic and biotic components of an organism's environment abiotic includes climate (temperature, precipitation, sunlight, wind) and soil (rock and minerals) biotic is all other organisms (symbiosis)
radial symmetry
symmetry around a central axis (can draw as many planes of symmetry as you want)
pentaradial symmetry
symmetry around a central axis with 5 planes of symmetry, as in Echinodermata
examples of selective pressures that can --> natural selection and adaptive evolution
temperature change, food scarcity, disease
Know pre-zygotic and post-zygotic reproductive barriers. What kinds of barriers maintain reproductive isolation between different species?
test yourself on the handout I guess barriers that happen before mating are the ones that maintain isolation between species?
features of Eukaryotic kingdoms?
test yourself using the handout
distinguishing characteristics of the three domains?
test yourself with the handout: cell type (prokaryotic or eukaryotic) cell number mode of feeding cell wall sexual life cycle also test yourself with class notes (this part focuses on Bacteria vs Archaea, the two prokaryotic domains): peptidoglycan in cell wall RNA polymerase initiator AA for protein synthesis introns in genes histones associated with DNA
What is the top soil and why is it such an important resource to soil life (including plants)?
top layer of the soil that contains the most organic matter (organisms need oxygen). Soil health really depends on the nutrients that these organisms produce - plants need those nutrients too
diploblastic
two tissue layers: outer is epidermis, inner is gastrodermis
phylogenetic/molecular species concept
use computers to build phylogenetic trees based on DNA, proteins molecular data clarifies fuzziness in morphology-based phylogenies
ecological species concept (how does it relate to conservation biology?)
used when populations of the same species have particularly distinctive habitats --> evolve different (unique) adaptations. common in conservation biology when scientists/activists want to preserve a species in a specific area (defining the species based on the area)
In what kinds of habitats would you expect to find lichens?
various: ground, tree trunks (often north-facing sides), moist areas some are very sensitive to air pollution, esp. metals/sulfur Lichen bio-accumulate metals: chemical analysis can indicate environmental levels - useful for monitoring pollution levels near large cities
synapomorphies for vertebrates
vertebrae
Skin of Osteichthyes (bony fishes): What does it feel like to touch? Why? (structure)
what it feels like: slimy with hard scales why: -layers of skin = epidermis and dermis (epidermis is outer layer) -scales = discs of bones in the dermis ("dermal scales") -epidermis is soft and produces slime See the powerpoint for a good illustration of these layers.
pre-adaptation
when a feature evolves in an organism for one purpose, then later becomes useful for something else
gametangium(a)
where gametes are produced
sporangium(a)
where spores are produced