Download LAB 1: Biology Tools and Techniques • Set up fungus culture

LAB 1: Biology Tools and Techniques
 Set up fungus culture: inoculate aspen wood shavings, wheat bran, gypsum, and
water mixture with fungal mycelium (network of fungal hyphae, tubular
filaments=basic growth form during vegetative phase) *Pleurotus sp. (PhylumBasidomycota)
 Set up fern spore culture: Using a serial dilution, *Ceratopteris sp. (PhylumPteridophyta)(C-fern) will later germinate and grown into reproductive structures
gametophytes.
 Set up Arabidopsis thaliana (Phylum-Angiosperm) seedlings in low phosphate or
control phosphate levels. Parafilm around plate to maintain sterile internal
environment and keep in moisture.
* Genus species or G. species or Genus sp. or multiple Genus spp.
1. Aseptic technique: used to ensure that organisms in the environment do not
contaminate cultures being studied, but also that the organisms studied are not released
into the environment (contaminating the lab).
 Use a Bunsen burner to sterilize the air
 Open bottles in a tilted position
 Hold the lid of petri plates at a 45° angle
 Don’t breathe directly onto cultures, solutions, or medium
2. Compound Light Microscope:
 3 lens system: condenser lens (focuses light on the specimen), objective lens
(magnifies the image), ocular lens (magnifies image and inverts it – contains ocular
micrometer)
 Body tube: contains prism that allows light to pass from objective lens to ocular
lens
 Stage: where slide is placed – moves so you can relocate specimen if you record
position of the rulers
 Revolving nosepiece: holds the objective lenses, attached to the bottom of the body
tube
 Iris diaphragm: adjust amount of light on specimen. Field iris diaphragm – focus
and center the light, adjust by turning ring. Aperture iris diaphragm – below the
condenser, adjust using lever.
 Condenser: lens under the stage that focuses light onto the specimen, move up or
down by turning knob.
 Coarse focus knob: raise/lower the stage to focus optics. Fine focus knob: finetune the focus.
 Parfocal: microscope should be closed to focus even when you change lenses. Just
fine tune using fine focus.
Magnification:
 Ocular micrometer gives measurement in eyepiece units.
1 epu at 10X = 10 micrometers
1 epu at 40X = 2.5 micrometers
 Magnification (M) = size of drawing/actual size of object (*convert micrometers to
millimeters!)
 We made wet mount of cyanobacteria then used dichotomous key (paired
statements, each statement is called a lead) to identify it = Gleocapsa.
Lab drawing:

Drawing on left side, details and labels to the right. Include caption and
magnification.
3. Dissecting Microscope: two eyepieces and two objectives – view material from slightly
different angles with each eye = 3D view. Uses lower magnification than compound
microscope.
 Ocular lenses, focus knob, body tube, arm, zoom adjustment knob, stage, and base.
Questions:
1. Was your microscope parfocal? YES – only needed to use the fine focus when
switched to a higher power objective.
2. Switching from low power to high power, change in brightness of the field of view?
YES – it goes darker because higher magnifications have thicker lenses (more light
gets reflected). Adjusting the iris diaphragm improves the contrast.
3. Advantages to using dissecting microscope: Gives a 3D view, you can manipulate
organisms with your hand rather than the toggle, you can view live organisms, and
you can view larger organisms.
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Aseptic (sterile) technique
Body tube
Compound light microscope
Condenser
Course focus
Dichotomous key
Dissecting microscope
Eye piece units
Eyepiece (ocular lens)
10.
11.
12.
13.
14.
15.
16.
17.
Fine focus
Iris diaphragm
Objective lens
Ocular micrometer
Parfocal
Serial dilution
Stage
Wet mount
LAB 2: Origin of Species
 Species: group of individuals that can interbreed, or have the potential to
interbreed, in nature.
 Speciation: a lineage splitting event that produces 2+ separate species. Caused by a
reduction of genes leading to a reproductively isolated population.
1. Allopatric speciation: geographic isolation
2. Sympatric speciation: reduction of gene flow
4 mechanisms of evolution: mutation, genetic drift, gene flow, and natural
selection.
 Phylogenies are used to depict species relatedness (genealogy – attempt to map the
relatedness/kinship among family members). Internal nodes represent speciation
events. Clade: shares common ancestor.

Constructed a phylogenetic tree for the Great Apes.
1. Listed binary traits (only two possibilities) – eyebrow ridge, relative
size of fist incisors, diff. shape between 1st and 2nd incisures, relative size
of tarsal bones, hindlimb length.
2. Polarize characteristic relative to the outgroup (close relative that we
know doesn’t belong to group being studied)
3. Mark character states for each one. 0=outgroup, 1=derived
4. Eliminate uninformative characters (autapomorphies – only 1 lineage
is derived, synapomorphies – shared within all members)
5. Construct simplest tree = maximum parsimony

Used necklace with 4 diff. beads to represent 4 diff. amino acids. You can tell by the
end results which groups had common ancestors. Two important elements:
1. There is a source of change – mutation, single-base substitution
- Continuous accumulation of mutations can be used to estimate
how long ago the ancestors of currently living species split into
different lineages = molecular clock hypothesis.
- Mutations must be neutral – can’t have a +/- effect on survival
or reproductive output
- Genetic marker used is cytochrome b – encoded on
mitochondrial DNA (mtDNA) and acquires neutral mutations
quickly.
2. Populations split/branch once in a while

We can also compare genotypes to make phylogenies based on DNA bases. We took
a multiple sequence alignment for the cytochrome b protein in the 8 great apes
(downloaded from NCBI). Orangutans split off first, then gorillas, then humans and
chimpanzees split.
Questions:
1. Why must the mutations used to determine an evolutionary rate be neutral?
Because they cannot have a +/- effect on survival or reproduction that would change
how quickly the species changed.
2. Why is mtDNA used in phylogenetic studies? It only comes from the mother,
therefore only changes due to mutations. Nuclear DNA gets recombined every
generation.
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Branch
Character states
Clade
Consensus tree
Gene flow (due to migration)
Genetic drift (due to random
sampling)
Genotype
Molecular clock hypothesis
Most recent common ancestor
Multiple sequence alignment
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
Natural selection
Neutral mutation
Node
Outgroup
Phenotype
Phylogenetic tree
Phylogeny
Single-base substitution
Speciation
Species
Taxa
LAB 3: Plants Pt. 1 – Plant Form and Function
 Plants are dynamic organisms – influenced by the environment in which they reside.
o Acquire resources by the root and shoot systems connected by vascular
tissues (continuous network of veins).
o Shoot system: apical bud
axillary bud
node (point of attachment)


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
leaf (petiole, attaches blade to stem, and bud) – capture light energy
via photosynthesis. Arranged in alternate, opposite, or whorled (3 or
more) pattern. Shape can be simple or compound (divided into
leaflets).
stem – maintain plant structure and transport
o Root system: absorption of water and nutrients. Taproot vs. fibrous system.
Taproot (largest and most important)
lateral roots
o 3 types of tissue:
1. Dermal tissue – outer layer of cells, covers entire plant, composed of
epidermis and the cuticle, occasionally trichomes/hairs present
2. Vascular tissue – run throughout whole plant, composed of xylem
(carries water up) and phloem (carries photosynthesis products down)
3. Ground tissue – background tissue, fills space between epidermis and
vascular tissue, may contain specialized cells
Internal Tissues (examined Helianthus sp. Phylum-Angiosperm) aka sunflower.
o Epidermis – outermost layer. Include trichomes/hairs that project. Cuticle is
the waxy outside covering.
o Cortex – tissue just interior to epidermis. Contains specialized cells; starch
storage, add support, contain chloroplasts for photosynthesis.
o Pith – central part of stem composed of storage cells
o Vascular bundle (xylem and phloem) – conductive tissue, also includes fibers
that serve as support and protection.
Internal structure of a leaf (examined Syringa sp. Phylum Angiosperm) aka lilac.
o Upper epidermis – outer layer on upper surface of leaf, covered by noncellular cuticle
o Palisade mesophyll – dense layer composed of elongated cells. PRIMARY
SITE FOR PHOTOSYNTHESIS.
o Spongy mesophyll – next photosynthetic layer, fewer chloroplasts and large
air spaces
o Lower epidermis – outer layer of cells on underside of leaf, contains
stomatal apparatus
o Stomata – two guard cells and the aperture/pore = gas exchange
o Veins/vascular bundle – conducting and supporting tissue of the leaf, xylem
and phloem, and supportive cells.
Role of essential nutrients on plant growth – Phosphate’s role on root structure in
Arabidopsis sp. (Angiosperm)
o Macronutrients needed: Carbon, Oxygen, Hydrogen, Nitrogen, Phosphorus,
Sulfur, Calcium, Potassium and Magnesium.
o Low phosphate gave shorter roots, darker green leaves, and less branching.
All hypotheses are testable, falsifiable, applicable to multiple cases, and based on
existing knowledge. Prediction is what you expect outcome to look like.
We use stats to demonstrate results are meaningful and not due to chance.
o Mean – average. Variability – how much values differ from mean.
o Use two-sample t-test – used because of continuous data. Null hypothesis
– pattern is due to chance alone. P-value is the probability of Ho being true
(we used p<0.05), if t-value is less, differences are not due to chance. Alphalevel is that cut-off (0.05). Degrees of freedom, relates the number of
different categories being studied.
o
o
The larger the difference between means, the higher the value of the tstatistic. The larger the variance within samples, the smaller the t-statistic.
Df=(n1-1)+(n2-1)…
Questions:
1. Is leaf shape important for photosynthesis? Yes, flat leaves would be better to
capture sunlight.
2. What do the veins on the leaves represent? They represent vascular tissues.
3. How to germination of Arabidopsis compare? No appreciable difference.
Vocab:
1. Compound leaf (divided into
leaflets)
2. Continuous data
3. Cortex (tissue just interior of
epidermis – specialized cells incl.
chloroplasts)
4. Count data
5. Critical value
6. Cross section
7. Cuticle (waxy, covers epidermis)
8. Degrees of freedom
9. Dermal tissues (outer layer:
epidermis, cuticle, trichomes)
10. Epidermis (outer layer)
11. Ground tissues (background tissue
that fills up space, may contain
specialized cells)
12. Lateral roots
13. Leaf
14. Leaf buds (apical vs. axillary)
15. Mean
16. Null hypothesis
17. Palisade mesophyll (layer below
upper epidermis, primary site of
photosynthesis)
18. Petiole (attaches blade of leaf to
stem of plant)
19. Phloem
20. Pith (central part of stem, storage
cells)
21. P-value
22. Qualitative
23. Quantitative
24. Root
25. Simple leaf
26. Spongy mesophyll (layer below
palisade mesophyll, less
chloroplasts, lots of space)
27. Statistical null hypothesis
28. Stem
29. Stomata/stomatal apparatus
30. Taproot (primary root is largest
and most important, as opposed to
fibrous root)
31. Trichome
32. T-statistic
33. T-test
34. Variance
35. Vascular bundle
36. Vascular tissues
37. Veins
38. Xylem
39. Alpha-level
LAB 4: Plants Pt. 2 – Plant Development and C-Fern Life Cycle
Four major groups of land plants derived from green algae:
1. Non-vascular plants (liverworts, mosses, hornwarts)
2. Seedless vascular plants (lycophytes, pterophytes)
3. Vascular seed plants (gymnosperms)
4. Vascular seed plants (angiosperms)
 Alternation of generations: Underlying pattern between all variations of land plants.
MEIOSIS -> haploid spores -> MITOSIS -> multicellular gametes (gametophyte (n)) ->
FERTILIZATION -> formation of zygote = diploid (sporophyte (2n))
 Sporophyte = visibly dominant. Gametophyte develops independently of sporophyte in
ferns.
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Homospory – one spore develops into sporangia and are bisexual (ex. mosses, ferns)
Heterospory – two types of spores (male and female) (ex. seed plants)
In Ceratopteris sp. = homosporous, simple haploid gametophyte -> diploid sporophyte
o Antheridia produce sperm that need water to swim and archegonia produce
eggs (water causes neck to open and release chemical).
o Two types of gametophytes: hermaphroditic (have archegonia and antheridia)
and male (have only antheridia). Sexual differentiation is controlled by
pheromone antheridiogen Ace.
o Hermaphrodites – absence of ACe, meristematic region, indeterminate growth –
releases ACe, so if on a plate with other spores, it inhibits growth of other
hermaphrodites.
o Males – presence of ACe, smaller, determinate, lack a meristem
To observe impact of population density on sexual expression, calculated density of
gametophytes on the plate and then quantified amount of hermaphrodite vs. male.
o Graphed average density of gametophytes (x) vs. percentage of sexual type (y)
Questions:
1. Why do some spores not germinate? Some just die, local contamination, some die
during spreader flaming.
2. Relationship between gametophyte density and sex expression? Higher density
gives more males. If few gametophytes, it is advantageous to self-fertilize; if lots of
gametophytes, hermaphrodites would want more males to breed with and it
promotes genetic variability.
3. How does sex expression occur? Thanks to pheromone-like ACe. In presence – males
develop.
4. Dilution experiment – control? Undiluted plate. Treatment? Diluted plates.
5. What happens when you add water to fern gametophytes? Mature antheridia will
release sperm that swim and congregate at the archegonia. Some will swim down
the neck of archegonium.
6. Where in the fern life cycle is organism most vulnerable? At fertilization. Sperm is
motile – it needs continuous and still water.
7. Life cycle:
Spore (n) -> MITOSIS -> male/female gametophyte (n) -> MITOSIS ->
FERTILIZATION -> zygote (2n) -> MITOSIS -> sporophyte (2n) -> MEIOSIS -> spore (n)
Vocab:
1. Alternation of generations
2. Antheridium
3. Archegonium
4. Determinate growth
5. Diploid
6. Egg
7. Embryo
8. Fertilization
9. Meristematic region (cells grow,
are indeterminate)
10. Mitosis
11. Pheromone
LAB 5: Kingdom Fungi
12.
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14.
15.
16.
17.
18.
19.
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21.
22.
23.
Sperm
Gametophyte
Haploid
Hermaphroditic
Heterospory
Homospory
Indeterminate growth
Meiosis
Meristem
Spore
Sporophyte
Zygote
Fungi include multicellular and unicellular forms. More closely related to ANIMALS than
plants. 5 major groups:
1. Chytrids
2. Zygomycota
3. Glomeromycota
4. Ascomycota
5. Basidiomycota
 All fungal cells have a rigid wall external to plasma membrane, the ability to absorb
compounds for metabolism, and the ability to reproduce by forming spores.
 Composed of tubular filaments (hyphae, nucleus=haploid), which form a network
(mycelium). Some mycelium differentiate into fruiting bodies =
mushrooms/puffballs/etc that we see. Purpose= provide protection, a durable
enclosure, and a dispersal device for haploid spores.
 Sexual reproduction:
1. Plasmogamy: fusion of cytoplasm from two opposing haploid hyphae (haploid
nuclei from each parent into 1 cell). Nuclei pair up => dikaryon (n+n)
2. Karyogamy: fusion of nuclei, forming a diploid zygote nucleus (2n)
3. Meiosis: produces four haploid (n) nuclei, which continue to germinate
(mitosis) until plasmogamy or asexual reproduction.
 Life cycle of Basidiomycota (Pleurotus sp. = Phylum Basidiomycota)
o Basidiocarp = mushroom = fruiting body
o Basidia line the gills, where spores are produced through meiosis.
 Asexual reproduction in Ascomycota (Penicillium sp. = Phylum Ascomycota)
o Mycelia can produce asexual spores = conidia that are on the tips of modified
hyphae (conidiophores).
o Fungus found in blue cheese – part of fungi imperfecti (multicellular, but only
found in asexual state). Conidiophore looks like a broom, spores are found at the
tip and grow in strings.
o Yeast is a unicellular fungus that reproduces asexually by budding – outgrowth
of parent cell, grows and forms a new cell.
 Mycorrhizae – mutualistic symbiotic associations between fungi & roots of vascular
plants, allow plants to survive in competitive communities by increasing the
physiologically active area of the root system (increases ability to capture water and
nutrients, increases tolerance to environmental extremes, and provides protection from
disease and pests). Fungus benefits because they receive photosynthetic products and
vitamins from the plants.
o Arbuscular: penetrate roots cells and form structures inside the cells.
o Ectomycorrhizal: do not penetrate, wraps around the root cells.
 Lichen - mutualistic association between fungal partner and algae/cyanobacterial cells
(fungal=Ascomycota, photosynthetic partner=unicellular Chlorphyta or Cyanobacteria)
o It is the algal layer that does photosynthesis, allows lichen to live. Lichen gets
organic C from algae, and N from cyanobacteria.
o Growth is super slow and dominate in mountain and arctic regions.
o 3 common growth forms:
1. Crustose – thallus forms a thin crust that grows right on top and is entirely
stuck to the surface (cannot be removed).
2. Foliose – thallus is flat and has leaf-like loves, attached with rhizines or is
circular and attached by a single cord (can be peeled off)

3. Fruticose – thallus is only attached at the base and grows outward, either
shrub-like or strand-like.
o Asexual reproduction =fragmentation of the thallus.
o Sexual reproduction = formation of ascocarps (confined to fungal partner)
o Used dichotomous key to identify different lichens.
Types of fungi:
1. Saprophytic: derive energy from the breakdown of organic material. Hyphae
produce enzymes that are secreted through plasma membrane.
2. Symbiotic: (with plants=mycorrhizae, with algae/cyanobacteria=lichen)
3. Parasitic: growing on foods – secrete deadly/toxic carcinogens.
Questions:
1. By what process do hyphae give rise to dikaryotic phase? Plasmogamy (fusion of
cytoplasm)
2. From observations of Penicillium sp. conidia, why do these fungi disperse so well
and are successful at contaminating food? They produce lots of spores.
3. How do plants benefit from mycorrhizal associations? Increase physiologically
active area of root system, increase plant’s ability to capture water and nutrients,
increase plant’s tolerance to extremes, and provides protection from disease and
root pests.
4. Where does the fungus get its nutrients? From the plant – photosynthetic products
and vitamins.
5. In which kingdom would you classify lichens? Fungae.
6. Two types of cells that make up lichen tissue? Algal/cyanobacterial cells and fungal
hyphae (predominant).
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
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Ascocarp
Cortex
Crustose
Foliose
Fruticose
Isidia
Pendulous
Propagule
Prostrate
Rhizines
Soredia
Thallus
Arbuscular mycorrhyizal fungi
Basidiocarp
Basidium
Conidiophore
Conidium
18.
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25.
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27.
28.
29.
30.
31.
32.
33.
Dikaryon
Diploid
Ectomycorrhizal fungi
Haploid
Hyphae
Karyogamy
Lichen
Meiosis
Mycelium
Mycorrhizae
Plasmogamy
Saprophytic
Spore
Symbiosis
Thallus
Yeast
LAB 6: Selection of Abiotic Environmental Factors in A. franciscana
 Ecology: study of interaction of individuals and their environment. Habitat selection:
preference for a certain habitat/condition, usually reflects most favorable conditions for
survival/reproduction.

Artemia franciscana = brine shrimp (Phylum – Arthropoda). Small aquatic
crustaceans, live in high salinity environments, and feeds on photosynthetic
photoplankton.
o Deal with extreme environments by producing resting eggs/cysts. Reproduce
asexually by parthenogenesis in stable conditions. Resort to sexual reproduction
in extreme factors, females produce thick-shelled, fertilized eggs that do not
hatch. Once immersed in saltwater, they then develop into nauplii (larvae). We
worked with first stage nauplii.
o We investigated whether Artemia occupy different conditions because they are
specialized or because they are tolerant for a wide range of conditions. Are they
specialists or generalists? (exposed them to gradients of ph, temperature, and
light) Counted living Artemia found in each section of gradient.
o Used chi-squared analysis – prove that difference from expected count is
because of treatment and not due to chance. Use this because it is frequency
data/count data (not continuous). Compares observed data with expected.
Either done by goodness of fit test (how well observed data fits expected
distribution) or contingency table analysis/test of independence (compares
observed distributions to see if they are different than expected by chance).
o Expected frequency is what you would expect if results are evenly distributed
due to chance (Ho is correct).
o Greater difference between data = larger chi square = lower probability that
they are due to chance.
o Df = number of categories – 1
o Calculated chi square > critical chi square, reject Ho (treatment has effect,
results are significant).
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
Alpha-value
Contingency table analysis
Chi square
Critical value
Degrees of freedom
Ecology
Expected frequency
Goodness of fit
9.
10.
11.
12.
13.
14.
15.
Habitat
Habitat selection/preference
Null hypothesis
Observed frequency
Procedural control
P-value
Scientific hypothesis
LAB 7, 8, 9: Biology of Invertebrates
Animalia are divided into two groups:
1. Basal animals – no true tissues (ie. sponges, phylum Porifera)
2. Eumetazoa – true animals, true tissues
o Divided into vertebrates (animals with backbones, subphylum of Chordata) and
invertebrates (animals without backbones, rest of phyla)
 Cnidaria – Hydra sp. = radial, dipoblastic, acoelomate, no segmentation.
 Platyhelminthes (flatworm) – Planaria = bilateral, triploblastic, acoelomate, no
segmentation
 Mollusca – pond snails = bilateral, triploblastic, schizocoelomate, no
segmentation
 Annelida – earthworms = bilateral, triploblastic, eucoelomate, metameric

Nematoda – vinegar eels = bilateral, triploblastic, pseudocoelomate, no
segmentation
 Arthropoda (class-insecta): bilateral, triploblastic, eucoelomate, tagmatized
– mealworms/darkling beetles
- Bean beetles
 Arthropoda (class-crustacea): bilateral, triploblastic, eucoelomate, tagmatized
- brine shrimp (artemia)
- daphnia
Body plan: set of morphological/developmental traits that characterize anatomical
organization. Includes:
 Body symmetry: bilateral or radial
 Tissues: dipoblastic (endoderm, exoderm) or tripoblastic (incl. mesoderm)
 Body cavities: Aceolomate, coelomate, or pseudopcoelomate
 Mode of development: (protostome or deuterostome).
Segmentation: repeated units (metameres)
 Tagmosis: when segments fuse/develop into specialized regions that carry out
different functions (ex. head, thorax, abdomen, cephalothorax).
 No segmentation, metameric, or tagmatized.
Appendages: found in bilateral animals, eventually specialized into legs, flaps, mating
structures, or lost.
We performed experiments on:
1. Feeding behavior – What do they eat and how? Requires production of sensory cues
by the prey, detection of the prey, attack by the predator, escape/defense by the
prey, and feeding.
2. Locomotion – How it moves? Impacts food gathering and predatory techniques.
3. Reaction to stimuli (taxes) – may be positive (organism moves towards stimulus) or
negative (moves away from stimulus).
 Chemotaxis, Gravitaxis/Geotaxis, Phototaxis, Rheotaxis (water current),
Thermotaxis, or Thigmotaxis (touch/pressure)
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
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Abdomen
Acoelomate
Bilateral symmetry
Body cavity
Body plan
Cephalization
Cephalothorax
Chemotaxis
Coelom
Diploblastic
Ectoderm
Thorax
Endoderm
Eumetazoa
Germ layer
Gravitaxis/geotaxis
Mesoderm
18.
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23.
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30.
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32.
33.
Metamerism
Phototaxis
Phylum Annelida
Phylum Cnidaria
Phylum Arthropoda
Triploblastic
Phylum Mollusca
Phylum Nematoda
Phylum Platyhelminthes
Pseudocoelom
Radial symmetry
Rheotaxis
Tagmatization
Taxes
Thermotaxis
Thigmotaxis
LAB 10: Intro to Deuterostomes
 Deuterostomes: include Echinoderms and Chordates – mesodermal endoskeleton,
enterocoelous formation (coelom from out-pockets of the embryonic gut tube),
deuterostome condition (formation of anus from embryonic blastospore), and radial
indeterminate cleavage.
 Phylum Echinodermata – marine invertebrates (sea stars, sea urchins, sand dollars,
sea cucumbers, brittle stars, and sea lilies)
o 5 part radial symmetry
o Calcareous endoskeleton
o Slow moving/sedimentary
o Initially bilateral symmetry -> shift to radial symmetry because of sedimentary
lifestyle = secondary radial symmetry (Note, some sea cucumbers have shifted
AGAIN to bilateral symmetry).
o Evolved water vascular system for feeding and locomotion (allows for
equivalent movement in all lateral direction).
o Sea stars – radial symmetry, crawl using tube feet (water vascular system)
o Sea urchins – radial symmetry, moveable spines of endoskeletal system
o Sea cucumbers – bilateral symmetry, elongated aboral axis, tube feet on one side
of axis, tentacles to trap food
 Phylum Chordata – Urochordata, Cephalochordata, and Vertebrata **All vertebrates
are chordates, but NOT all chordates are vertebrates.
o Notochord: longitudinal, endoskeletal rod gives strength and elasticity to the
body. Eventually replaced by vertebral column in most adults.
o Dorsal hollow nerve cord: longitudinal, fluid-filled nerve cord runs dorsally
just above notochord. (called spinal cord in vertebraes)
o Pharyngeal gill slits: lateral openings in the pharynx of chordates. Originally
used for filter feeding, as stream of water entered through the mouth and exited
through the slits.
 Aquatic – gill tissue is associated with slits, specialized for gas exchange
 Terrestrial – lung breathing, gill slits are transitory structure only found
in early embryonic stages.
o Segmentation of MUSCLES
o Ventral heart
o Post-anal muscular tail
o We observed Branchiostoma sp (Phylum-chordata) – swims, burrows, and
filter feeds. Shows three imp. characteristics (notochord, dorsal hollow nerve
chord, and pharyngeal slits), as well as myomeres (muscle segments), oral
hood (surrounded by tentacles, sort incoming particles), atrium (common
chamber where filtered water collects), water exits from atrium through the
atripore.
 It is the presence of an endoskeleton (cartilage, or cartilage+bone) that has allowed
vertebrates to reach large body size. Allowed us to use variety of food source and modes
of locomotion.
o Bony fish:
1. Vertebral column – (mostly axial skeleton, incl. skull) divided into two:
the trunk and the tail. Vertebrae show different processes, but little
specialization. Myomeres act directly on vertebral column to generate
lateral swimming movements. Axial does most of the work for
locomotion.

2. Appendages – unpaired fins (dorsal, anal and caudal fins) and paired fins
(pectoral and pelvic fins). These make up the appendicular skeleton.
o Tetrapods
1. Vertebral column – much more complex because it must counteract the
force of gravity. Also, axial interacts with appendicular skeleton for
locomotion. Specialized vertebrae:
 Cervical vertebrae – neck vertebrae behind skull (7). First = atlas,
allows skull to nod up and down. Second = axis, skull rotates left and
right.
 Thoracic vertebrae – bear ribs (protect heart, lungs, and help
breathing)
 Lumbar vertebrae – between rib cage and pelvic region, robust and
rigid, strengthen the back
 Sacral vertebrae – fused to pelvic girdle
 Caudal vertebrae – tail vertebrae behind sacral region. In humans,
very reduced.
2. Girdles – pectoral girdle (not attached to vertebral column, maintained
by muscles and connective tissues, shoulder blades and collar bones).
Pelvic girdle (anchored to vertebral column in sacral region where
ilium is fused, anchored to anterior pubis and posterior ischium ->
socket where hind limb inserts into girdle).
3. Limbs and appendages – Share a suite of homologous bones inherited
from fish ancestor, but have been greatly modified depending on
locomotion. Fore limbs and hind limbs all articulate with pectoral or
pelvic girdle. All consist of single long bone and two parallel bones.
Smaller bones make up wrists/ankles, longer bones for hand/foot and
end in digits.
Dissected a yellow perch (Perca flavescens, Phylum – Chordata).
o External features: head, trunk, tail regions, anus, operculum (gill cover), gill
slits, dorsal, anal, caudal, pectoral, and pelvic fins. Nares (nostrils) are not
used for respiration, but are lined with olfactory cells. Lateral line across
the fish extends from operculum to caudal fin, is the sensory system that
detects vibrations and changes in water pressure (currents and movements
of other organisms)
o Respiratory system: Composed of bony gill arches, that have gill
filaments that consist of tiny lamellae which contain capillary beds (gas
exchange). Gills ventilated with a unidirectional flow of water, maintained
by action of muscular pumps in mouth/opercular cavities (mouth ->
pharynx -> gill lamellae -> gill chamber -> opercular opening)
o Circulatory system: The heart has two chambers: atrium (collects deoxygenetad blood) and ventricle (pumps blood through the ventral aorta to
gills).
o Swim bladder: runs along the top of the body cavity, filled with oxygen,
nitrogen, and CO2, and functions as hydrostatic organ (adjust specific
gravity so the fish is neutrally buoyant, neither rising or sinking by adjusting
concentration of gases).
o Digestive system: the liver is associated with gall bladder to store bile.
The stomach joins the intestine at the pylorus. Also contains masses of fat
and the pancreas.
Lumbar, sacral,
and gidle =
anchorage
points for major
muscles that
operate the hind
limbs.
Urogenital system: excretory and reproductive tracts are associated.
Excretory collects/disposes nitrogenous wastes from protein metabolism
and regulates ionic and water balance. Reproductive system produces
gametes (eggs or sperm) and releases them – external fertilization and
oviparity. (More complex for species with internal fertilization and internal
development). Share common sets of ducts and openings because
convenient routes. Kidneys are joined to urinary ducts and empty into
urinary bladder. Gonad lies beneath bladder – ovary or testes. Female have
a single urogenital pore for urine and eggs, males have separate urinary and
genital pores.
Compared this to the rat.
o Respiratory: two lungs, trachea, bronchi, muscular diaphragm
(ribs+muscular diaphragm = contract to inflate/dilate the lungs). Two
circuits (systemic and pulmonary)
o Digestive: NO gall bladder, large caecum, large intestine, liver, spleen,
stomach, pancreas, colon, and anus.
o Urogenital system: kidney, internal fertilization and viviparity (embryo
development inside of female).
o

Questions:
1. Why is the radial symmetry found in echinoderms considered to be secondary?
They started out bilateral, but developed radial because of sedentary lifestyle.
2. What is the function of the water vascular system in echinoderms? Locomotion and
feeding.
3. What are the characteristics that echinoderms and chordates share? Mesodermal
skeleton, enterocoelous formation, deuterostome condition, and radial,
indeterminate cleavage.
4. How does Branchiostoma sp. feed? Filter feeds – tentacles sort particles as water
enters, mucus on pharyngeal slits traps edible particles.
5. What part of Branchiostoma sp. shows segmentation? Muscles = myomeres.
6. What types of features are required to filter feed? Tentacles create water current,
water exits through atripore, and pharyngeal slits filter the water.
7. Does the pelvic girdle belong to the axial or appendicular skeleton? Appendicular.
8. Basic difference between locomotion in fish and tetrapods? Fish use mostly axial for
lateral swimming motions, tetrapods use mostly appendicular (acts with axial to
counteract weight).
9. Why are there these differences? Fish are supported by water; they can use simple
movement and specialize in other things. Tetrapods must counteract gravity, so they
need a complex skeleton.
10. Why does the pigeon have a large breastbone associated with the thoracic vertebrae
and ribs? It’s a large muscle – supports its pectoral muscles used to fly.
11. Why is the human’s pelvic girdle so strong and robust? It supports the torso and acts
as attachment point for the legs.
12. What adaptations to a bipedal upright lifestyle are evident in the human skeleton?
Strong, more rigid vertebral column, and the attachment of vertebral column is on
the BOTTOM of the head (not the back!)
13. How does the fish get its oxygen? Gills have blood flow that runs against water flow,
oxygen diffuses from SOLUTION (suffocate in air).
14. What structure other than the kidneys plays a role in metabolite balance in the
perch? The gills – they regulate osmotic balance.
15. Why are the gonads of the perch so large? They are able to have a lot of offspring
thanks to external fertilization.
16. Differences between the heart and circulatory system of perch and mammals? Perch
has single circulation, only oxygen-poor blood is pumped through the heart.
Mammals have double circulation, the heart is divited into two sides (oxygen poor
and rich).
17. Advantage of having separate systemic and pulmonary flows? More control.
18. Function of the liver? A digestive organ. Captures excess glucose as glycogen –
regulates sugar levels.
19. Testes of male mammals are located outside the body cavity vs. testes of a perch are
inside? Depends how they regulate their body temperature – mammals regulate
their own temperature internally.
Vocab:
1.
2.
3.
4.
5.
6.
7.
8.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
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43.
Appendicular skeleton
Artery and vein
Atripore
Atrium
Axial skeleton
Bronchus
Caecum
Chordata
Esophagus
External fertilization
Gamete
Gill
Gonad
Heart
Homologous
Hydrostatic organ
Internal fertilization
Intestine
Kidney
Lamella
Lateral line
Liver
Lung
Muscular diaphragm
Myomere
Nares
Notochord
Operculum
Oral hood
Oviparity
Pancreas
Pectoral and pelvic girdle
Pharyngeal gill slits
Phylum Echinodermata
Pulmonary and systemic flow
Respiratory system
9. Circulatory system
10. Colon
11. Deoxygenated vs. oxygenated
blood
12. Deuterostome
13. Digestive system
14. Dorsal hollow nerve cord
15. Endoskeleton
44. Secondary radial symmetry
45. Segmentation
46. Spleen
47. Stomach
48. Swim bladder
49. Tetrapod
50. Trachea
51. Urinary bladder
52. Urogenital system
53. Ventricle
54. Vertebrae
55. Viviparity
56. Water vascular system