-
Provide a technical definition of an animal
- Multicellular heterotrophic eukaryotes that
- ingest food items, with tissues that develop from embryonic germ layers
-
How does the animal condition differ from that
found in fungi & plants (remember that plants & fungi are also multi-cellular)?
- They are mostly photoautotrophs who get energy from light or chemoherterotrophs who
- get energy from organic compounds
-
Characterize choanoflagellates (i.e., size,
morphology) and explain why choanoflagellates are thought to be closely-related
to animals?
Small aquatic with flagella
- Related because they are unicellular but often
- live as colonies
-
What are three primary apomorphies for Metazoa
(animals)
- ·
- 1000s of shared genomic changes in the genome,
- unique to animals
- ·
- HOX genes (highly-conserved developmental
- regulatory genes)
-
What are the primary molecules in and fractions
of the extracellular matrix?
- ·
- Glycoproteins (protein + carbo molecules =>
- proteoglycans) & collagen
-
What is a “body plan”
- ·
- Description of the overall system of body
- organization (e.g., symmetry, tissue complexity, appendages, segmentation,
- etc.)
-
What are the habitat characteristics of most
major Metazoan groups? Exceptions?
- ·
- Mostly aquatic with exception in vertebrates and
- arthropods
-
About how many species of invertebrate animals
have been described? What about vertebrate animals
- ·
- Only 50,000 of the known species 1.3 million
- species are vertebrates
-
Provide a brief timeline of life on earth,
including 1.) age of earth, 2.) fossil evidence for first life, 3.) fossil
evidence for first Metazoans?
- ·
- Earth: ~ 4.6 billion YA
- ·
- First fossil evidence for life: ~3.5 million YA
- ·
- Fossil evidence of first Metazoans: ~560 MYA
-
What is the Cambrian Explosion? When did this
occur? Why is this event called an “explosion”?
- ·
- All primary animal groups appears suddenly, lots
- of diversity over a very short period of time
-
Provide three explanations for the Cambrian
Explosion?
- ·
- Diversification in HOX gene cluster (major
- genomic changes, causing major morphological changes)
- ·
- Increased atomospheric oxygen => increased
- metabolic rates, larger sizes
- ·
- Escalation of predator-prey relationships
- (development of more complex food-webs)
-
Describe, in general terms, how a molecular
clock is applies
- ·
- Known divergence dates for subset of living
- species (from fossil or biogeographic constraints)
- ·
- Observed genetic distance from same subset of
- living species (e.g., 100 nucleotide differences in 1000 bp gene= 10%
- divergence) => convert this to the rate of genetic divergence per unit time
- (e.g., 1% divergence per million years)
- ·
- Estimate divergence dates for other living
- species based on genetic divergence values only
-
What are the three main groups of sponges, and
how are they distinguished?
- o
- Skeletons comprised of collagen or sponging
- protein
- o
- Skeletons of calcium carbonate spicules
- ·
- Hexactinellid Sponges (glass sponges)
- o
- Skeletons made of fused silica spicules
- o
- Typically live at great depths in oceans
-
What are two primary features that suggest a
relatively early phylogenetic divergence for Sponges?
- ·
- Cellular grade of organization (GoO)- lack true
- embryological germ cell layers, lack adult tissue layers (contrasts with tissue
- GoO all other animals )
- ·
- More cell individuality then typical cells in
- remaining animals (some cells mobile, and cell differentiation is reversible)
-
Discuss the general characteristics of Sponges
(e.g. habitats, symmetry, lifestyle, fossil record)
- ·
- ~8000 described species
- ·
- Fossil record to Cambrian
- ·
- Lack organized body symmetry (~asymmetrical)
-
How are sponge bodies supported?
- ·
- By a gelatinous matrix (mesohyl), supported by a
- skeleton of spicules (calcium carbonate; silica) and/or protein (collagen,
- sponging)
-
What are the three primary cell types found in
sponges, and what are their specific functions?
- ·
- Porocytes- cells surrounding pore (ostia)
- opening
- ·
- Amoebocytes- food transport, structural support
- (e.g., producing spicules)
- ·
- Choanocytes (collar cells)- create water
- currents and trap microscopic food particles/gametes; also involved in egg
- & sperm production
-
How do choanocytes work, and how are these cells
fundamental to the sponge design?
- ·
- They create a current which pulls water into the
- sponge where it gets its nutrients and disposes of waste
-
Why aren’t sponges typically eaten or
over-grown? (two reasons)
- ·
- Glass or calcite spicules
- ·
- Production of various bio-active compounds,
- often in association with symbiotic bacteria
-
Be able to discuss the biological properties of
the sponge molecule sceptrin
- ·
- Anit-cancer, anti-fungal, anti-inflammatory
- ·
- Inhibits cell mobility in various cancer cell
- lines
-
Define “DNA barcoding.” Why are sponges a good
candidate group for the applications of DNA barcoding?
- ·
- DNA Barcoding: use of rapidly-evolving sequences
- for species identification
-
What is the defining feature for Eumetazoan
animals?
- ·
- They have true tissues, derived from embryonic
- germ cell layers (EGCLs)
-
Define diploblastic. What are the two embryonic
germ cell layers in diploblasts, and which tissue layers do these give rise to
in Cnidaria?
- ·
- Diploblastic: have 2 EGCLs (ectoderm &
- endoderm)
- ·
- Endoderm -> gastrodermis
-
Define radial symmetry. Define filter-feeder.
- ·
- Radial symmetry: multiple planes resulting in
- equivalent halves
- ·
- Filter-feeder: pass food particles past a
- capturing organ
-
What is the function of the gastrovascular
cavity in Cnidarians? How does this function relate to basic cellular
requirements (i.e., nutrition, respierations, etc)?
- ·
- Gastrovascular cavity: simple transport system
- for exchange of food items, gases, wastes
-
What is the function of cnidocytes and
nematocysts?
-
What is the mechanism of nematocyst discharge in
Hydra cnidarians?
- ·
- Combination of osmotic pressure (calcium ions
- dumped from capsule into cytoplasm), plus energy stored in mini-collagen
- proteins of capsule wall
-
Contrast and draw the two diploid morphological
types found in Cnidaria polyp vs. medusa
- ·
- Polyp: oral side up, typically sessile, benthic
- habitats
- ·
- Medusa: oral side down, free-floating, pelagic
- habitats (open ocean)
-
Discuss the colonial body organization of
Physalia
- ·
- A colony of physiologically-connected 2N
- individuals (zoolids), derived from a single zooid by budding
-
1.)
What are the four major groups of Cnidaria, and
how do these groups differ in which morphological type (i.e., polyp or medusa)
is the dominant lifestage?
- o
- Both polyp and medusa stages
- o
- Polyp stage absent or reduced
- o
- Polyp stage short-lived, in most cases unknown
-
What are coral reefs? What are coral reefs economically
& ecologically valuable?
- ·
- Corals: some hydorzoans, mostly anthrozoans
-
What are the “localized” and “global” threats to
coral reefs?
- ·
- Localized: land-based pollution (chemicals &
- sedimentation), mining, “blast” fishing
- ·
- Global: waters too warm (photosynthetic
- dinoflagellates are expelled, corals “bleach”), declining pH associated with
- absorption of increased CO2 (coral calcification decreases with declining pH
-
What are three main innovations defining
Bilateria?
- ·
- Organ systems (primary four: digestive, respiratory,
- excretory, circulatory)
- ·
- Bilateral symmetry & cephalization
- ·
- Triploblastic-> 3 EGCLs
-
Define bilateral symmetry and cephalization
- ·
- Bilateral symmetry: single plane of symmetry
- divides body into mirror halves
- ·
- Cephalization: concentration of feeding organs,
- sensory & neural structures at the anterior end of body
-
What is the triploblastic condition? What are
the ultimate developmental fates of the three individual triploblastic germ
cell layers in bilaterians?
- ·
- # EGCLs: endoderm, ectoderm, mesoderm
- ·
- Ectoderm: outer body covering, nervous system
- ·
- Endoderm: gut lining, liver, lungs
- ·
- Mesoderm: true muscle tissue, bone, connective
- tissues, etc…
-
Give examples of protostome animals and Deuterstome animals
- ·
- Protostome: arthropods, mollusks, various worms,
- etc. (most invertebrates)
- ·
- Deuterostomes: star fish, hemichordates,
- chordates
-
What are the primary differences between
Deuterostomes vs. Protostomes? –remember the Table of differences
- ·
- Position of nervous system
- (ventral in protostomes, dorsal in deuterosomes)
- ·
- Gene duplication in HOX gene family
- (no duplication in protostomes, duplication of posterior HOX genes in deuterostomes)
- ·
- Fate of blastopre (earliest opening of future
- gut during embryonic development)
- (mouth in protostomes, anus in seuterostomes)
-
Three genomic processes have resulted in the HOX
gene differences observed between Protostomes and Deuterstomes- what are these
precesses?
- ·
- Duplication of genes on a single chromosome->
- resulting in “family” of related genes
- ·
- Whole genome duplication (2X) in early-diverging
- deuterostomes
- ·
- Some genes lose functional redundancy
-
Define gastrulation, blastopore, and
archenteron.
- ·
- Gastrulation: invagination of endoderm to form
- archenteron (future gut)
- ·
- Blastopore: earliest opening of future gut
- ·
- Archenteron: future gut
-
What are the primary characters supporting the
Lophotrochozoans (molecular or morphological)? What are the two morphological
features found in some, but not all Lophotrochozoans?
- ·
- Some taxa with lophophore (ciliated feeding
- structure), some taxa with trochophore larvae
-
What are the primary phylogenetic groups of
Platyhelminthes, and the lifestyles of these primary taxa?
- ·
- Turbellaria- not parasites
- ·
- Monogenea- fish ectoperasites
- ·
- Trematoda- vertebrate endoparasites
- ·
- Cestoda- animal endoparasites
-
Summarize the morphological features found in a
“generalized platyhelminth” (e.g., symmetry, cell layers, placement of nervous
system, etc.)
- ·
- Expected bilaterian features: bilateral
- symmetry, cephalized, triploblastic
- ·
- Highly-branched blind, gut
-
Define parasitism. Your friend tells you that a
parasites are lowly animals, barely evolved. You respond, “no sir, “ parasites
are actually very successful, for the following reasons…
- ·
- Parasitism: benefit at expense of host
- ·
- Essentially all animal groups include some
- parasitic representatives, perhaps ½ of all animals species are parasites, and
- basically all animals serve as hosts for one or more parasites
-
Discribe and illustrate the complex lifecycle of
a Schistosoma fluke. What is the biological significance of larval stages that
use intermediate hosts?
- ·
- The larva uses the intermediate host as a
- mechanism for reaching the new primary host
-
Talk about the global distribution, prevalence,
and impact of Schistosomiasis in humans.
- ·
- Distributed in tropical countries around the
- world
- ·
- Causes chronic illness or liver/kidney damage
- (symptoms in response to egg deposition), ~20 million humans severely ill, with
- over 200 million people infected worldwide
-
Schistosoma flukes have three cellular/molecular
mechanisms that prevent detection by the host immune system- what are these
mechanisms?
- ·
- Mask surface with host proteins-> immune
- masking
- ·
- Syncytium is not a static layer, undergoes
- frequent transformation
- ·
- Very few parasite proteins expressed exclusively
- in wall of tegument (few targets for host immune response)
-
Why is the sequencing of the Schistosoma genome
potentially important in the control of Schistosomiasis.
- ·
- We can disable fluke genes that are necessary
- for metabolism/survival/reproduction in human host
-
What is the general bodyplan of a cestode
(tapeworm)? -function of scolex & proglottids? How do tapeworms gain
nutrients without a digestive tract?
- ·
- Scolex- attachment devices
- ·
- Proglottids- long chaing of reproductive
- segments
-
Symmarize the species and ecological diversity
of mollusks. What are the 3 major groups of mulluscs, with examples of each?
- ·
- Gastropoda (snails, slugs)
- ·
- Bivalvia (clams, mussels, scallops, oysters)
- ·
- Cephalopoda (squids, octopuses, cuttlefishes,
- chambered nautiluses)
-
Most (not all) mollusks share 3 primary features
in common. What are these? What are possible functions of these primary
features?
- ·
- Ventral muscular foot: used for locomotion, as
- holdfast, and feeding
- ·
- Visceral Mass: houses internal organs (primary
- four)
- ·
- Dorsal Mantle: cell layer that secretes shell
- for protection against predation, prevents mechanical damage, prevents
- dessication (when terrestrial)
-
Some opisthobranchs lack shells. How do they
protect themselves from the predators that abound in marine habitats?
-
What are conotoxins? How has conotoxin diversity
evolved?
- ·
- Conotoxins- bioactive peptides (small 10-40 AA
- protesting)
- ·
- 50,000-100,000 different peptides having evolved
- in genus
-
Provide details of one example of a conotoxin
that has been developed as a drug- e.g. how does the drug work? Why is the drug
a nice alternative to morphine?
- ·
- Prialt: non-addictive, anti-tolerance treatment
- for severe chronic pain
- ·
- Selectively blockes voltage-gated calcium
- channels (propagates action potentials)
-
Many cephalopods, like some snail groups, have
lost their shell, how are such animals protected from predation
Fast, well camouflaged, and cryptic
-
Cephalopods have a camera-lens type eye.
Illustrate this condition. This type of eye is said to have evolved
convergently in cephalopods and vertebrates- what is meant by this?
- ·
- Camera-lens eye: functionally very similar to
- vertebrate eye
- ·
- Convergent: came to the same conclusion (in this
- case independently)
-
What is primary morphological apomorphy for the
protostome group ecdysozoa? What is ecdysis?
- ·
- Primary morphological apomorphy
- o
- Protein based outer body covering (cuticle)
- which is periodically molted for growth
- ·
- Ecdysozoans= “molting animals”
-
Ecdysozoan phylogenetic groups fall into 2
general categories- what are these, and how do these groups differ?
- o
- Lack appendages, mostly marine, possess internal
- fluid-based skeleton (hydrostatic skeleton)
- o
- Cuticle with structural polysaccharide chitin
-
What are the arthropod relatives? What features
do they chare with arthropods (at least 3)?
- ·
- Tardigrada “Water Bears” & Onychopora
- “velvet worms”
- o
- Evolution of appendages
- o
- Cuticle with structural polysaccharide chiting
-
Many biologists claim that arthropods are the
most successful animal lineage. What are 3 measures of “evolutionary success”
for Arthropods.
- ·
- Species diversity- 2/3 of every known animal
- species is an arthropod
- ·
- Ecological diversity- live in all habitats
- ·
- Numerically dominant metazoans- some estimates
- suggest a billion, billion individuals
-
What are the four main groups of living
arthropods, and the habitats in which each group can be found?
- ·
- Crustacean- marine and freshwater (lobsters,
- crabs)
- ·
- Hexapoda- terrestrial, some have secondarily
- evolved back into freshwater (insects)
- ·
- Chelicerata- marine and terrestrial (scorpions,
- spiders, horseshoe crabs)
- ·
- Myriapoda- all terrestrial (centipedes and
- millipedes)
-
Outline the timeline of diversification for
arthropods, including 1) time of origin in the fossil record 2) general timing
of terrestrial invasions.
- ·
- First appearance duing the Cambrian explosion
- ·
- First animals to invade land ~400 MYA
-
What are 3 important functional characteristics
of the chitinous cuticular exoskeleton or arthropods?
- ·
- Strong, lightweight material for a supportive
- exoskeleton but allows mobility
- ·
- Varies from very hard to very flexible (flexible
- joints key to movement)
- ·
- Waxy outer layer provides waterproofing (key to
- terrestrial invasion)
-
Why is the arthropod exoskeleton important in
terrestrial environments?
- ·
- Provides support for the organism, which is not
- needed in water
- ·
- Provides waterproofing to prevent water loss
-
Chhitinois cuticle is used to build important
body structures in arthropods- give 3 examples.
- ·
- Respiratory structures (tracheal system), gills
- ·
- Thin cuticular membranes used to sense
- vibrations & sounds
- ·
- Cuticular structures used to produce sounds
-
What are 5 reasons for the success of insects?
- ·
- Important interactions with plants (pollination,
- plant-feeding)
- ·
- Most diverse groups (but not all insects) with
- complete metamorphosis
- ·
- Complex sensory organs (senses of vision,
- hearing, olfaction, touch all highly evolved
-
Insect wings are not appendages, explain. How
does this differ from the condition seen in other animals with powered flight?
- ·
- Wings are not appendages (cuticular extensions
- of dorsal thorax) which does not forfeit functionality of appendages
-
What are possible advantages of powered flight?
- ·
- Colonizing new regions/habitats
- ·
- Ability to effectively pollinate plants
-
Why are insects good pollinators? Which insect
are the most diverse pollinators? Pollination is a so-called +/+ ecological
interaction- what is benefit to insects from this interaction?
- ·
- They are good pollinators because they can
- easily fly from plant to plant
- ·
- Most diverse pollinators (the big four):
- coleopteran (beetles), hymenoptera (bees, wasps, ants), Lepidoptera
- (butterflies, moths), and dipteral (true flies)
- ·
- Plants receive fertilization while insects are
- rewarded with nutrient-rich nectars and pollen
-
What does complete metamorphosis mean? What are
the lifestages of an insect with complete metamorphosis? What is a primary
ecological implication of complete metamorphosis?
- ·
- Complete metamorphosis: involves a major
- morphological change during development (ex. Caterpillar -> butterfly)
- ·
- Egg-> larva-> pupa -> adult
- ·
- Promotes insect diversification
-
Do all insects have complete metamorphosis?
Explain this in phylogenetic terms
- ·
- Two other types or metamorphosis
- o
- Intermediate: immature “mini-adults” lacking
- wings
- o
- Simple: immature “mini-adults”
-
What are the different types of insect
parasites? Explain why parasitism might promote insect species diversification?
- ·
- Parasites for other insects
- ·
- Parasites for other parasites
-
What are the 3 primary groups of chelicerate
arthropods, and the habitat characteristics of each group?
- ·
- Horseshoe crabs (marine)
- ·
- Pycnogonids (sea-spiders)
- ·
- Arachnids (terrestrial)
-
What are 3 key adaptations for predation seen in
spiders
-
Spider webs are made from silk proteins. Where
are these proteins produced, and what are some of the biological properties of
these proteins?
- ·
- Abdominal glands (feet of tarantulas)
- ·
- Very strong, extensible, and tough material
-
Why is the mass production of spider silks (for
human use) difficult? How are researchers overcoming this hurdle?
- ·
- Very small amount is produced but researchers
- are using other animals (ex. Goats) to produce these proteins
-
Spider venoms evolved in the context of what
type of prey items? What percentage of spiders are medically dangerous to
humans? What are some other potential applied beneficial uses of spider venoms?
- ·
- Out of 40,000 spider species only 40 are
- medically dangerous to humans
- ·
- Inhibits atrial fibrillation (abnormal heart
- rhythm)
-
The brown recluse causes necrotic arachnidism-
what is this? What is the range of the brown recluse in North America? What is
the nature of the medical misdiagnosis problem in western North America?
- ·
- necrotic arachnidism = kills cells
- ·
- brown recluse lives in eastern-central of the US
- ·
- misdiagnosis comes from other diseases (ex. Lyme
- disease) that causes the death of cells
-
There are 3 over-arching goals to research in
the Hedin lab- what are these general goals?
- ·
- Seek to discover & describe new arachnid
- species, and understand where these species are found (the who and where of
- biodiversity)
- ·
- Conduct molecular systematic studies to
- understand “how evolution works”
- ·
- Use knowledge gained to inform conservation
- efforts
-
What are the important findings for the
mygalomorph species Atypodies riversi? How do these specific findings relate to
the more general goals of the Hedin lab?
- ·
- How spread out they are in California and the
- different species living in different areas shows how they have spread out over
- time
-
Review the primary differences between
protostomes and deuterostomes.
- ·
- Protostomes: no HOX gene duplication, blastopore
- becomes mouth, ventral NS
- ·
- Deuterostomes: HOX gene duplication, blasstopore
- becomes anus, dorsal NS
-
Why do echinoderms fossilize well, how old are
these fossils, and what is somewhat special about extant versus extinct
echinoderm diversity?
- ·
- Endoskeleton helps echinoderms fossilize well
- ·
- Fossils dating back to the Cambrian explosion
-
How do we know that echinoderms were derived
from an ancestor with bilateral symmetry? What does echinoderm phylogeny
suggest about the evolution of body symmetry in echinoderms?
- ·
- Larvae of echinoderm show bilateral symmetry
- suggesting secondarily evolved radial symmetry
-
Why do mostly radial echinoderms “break the
rules” regarding the radial/sessile expectations?
- ·
- Radial animals tend to be sessile but
- echinoderms are fairly active animals
-
What are the unique characteristics of
echinoderms found in no other animal groups?
- ·
- Calcareous endoskeleton
- ·
- Water vascular system connected to tube feet
-
Endoskeletons are not developed to the same
extent in echinoderm groups- provide 2 examples of conditions at opposite ends
of the spectrum.
- ·
- Sand dollar (very hard with more calcareous
- ossicles) vs sea cucumber (very soft with fewer calcareous ossicles)
-
Describe the water vascular system; describe how
tube feet work and their functions.
- ·
- Echinoderms
- move by alternately contracting muscles that force water into the tube feet,
- causing them to extend and push against the ground, then relaxing to allow the
- feet to retract
- ·
- Tube
- feet used for: locomotion, food capture, and respiration
-
Describe digestion, excretion, respiration, and
circulation in a starfish.
- ·
- Digestive system is sometimes incomplete
- ·
- Respiration trough dermal gills and tube feet
- ·
- Direst excretion (osmoconformers)
- ·
- Bisexual, typically separate sexes
-
How do starfish differ from brittle stars?
- o
- Arms distinct from central disc which are used
- directly for locomotion and not tube feet
-
Define asexual reproduction. Why do we call offspring formed via asexual reproduction
clones?
- ·
- Single parent (no gametes)
- ·
- Offspring is genetically identical to one
- another and parent
-
What are the “pros & cons” of asexual reproduction?
- ·
- Pro- allows rapid increase in numbers of
- individuals
- ·
- Cons- lack of genetic variation in populations
-
Discuss 2 main types of asexual reproduction found in invertebrate animals, with
examples.
- ·
- Budding- new individuals arise as outgrowth
- (bud) of parent, develops then detaches from parent (ex. Budding of medusa from
- polyp in cnidarians)
- ·
- Fragmentation- adult breaks into 2 or more
- parts, each fragment capable of becoming a complete individual via regeneration
- (ex. Planarians (platyhelminthes), and satfish (echinoderm))
-
Be able to illustrate a “standard” bisexual, sexually-reproducing life cycle.
- ·
- Haploid gametes (fertilization)-> diploid egg
- (mitosis)-> adults (meiosis)-> gametes
-
How are sexual gametes formed, and what is the genetic significance of this
process?
- ·
- 1.) independent assortment of chromosomes 2.)
- recombination during meiosis results in genetically unique gametes
- ·
- Entire population of individuals are genetically
- variable
-
What is the evolutionary significance of meiosis?
- ·
- Creates offspring that are genetically different
- from parents and each other
-
Contrast the dioecious condition to the monoecious condition?
- ·
- Monoecious- single individuals with bother M
- & F sex organs
- ·
- Dioecious- 2 different individuals with only one
- sex organ (M or F)
-
How does haplodiploidy in hymenopteran insects work?
- ·
- Haplodiploidy- qeen bees produce haploid eggs
- with become drones but if fertilized it becomes a diploid queen or worker bee
-
Define external fertilization, and explain why such fertilization is expected to be
less common in terrestrial habitats?
- ·
- External fertilization- haploid eggs fertilized
- outside the F body
- ·
- Uses water as a median for gametes to travel to
- each other
-
Gametes of marine invertebrates that are external fertilizers face 2 problems- what are
these?
- ·
- How do gametes find each other in the huge ocean
- ·
- How do gametes recognize conspecific gametes
-
Define chemotaxis, and give a specific example of a chemical that causes chemotaxis.
- ·
- Chemotaxis- gradient of chemicals secreted by
- egg that “guides” sperm toward it
-
What is the acrosomal reaction, and how do species-specific proteins come into play
at this stage?
- ·
- Break-down of acrosomal membrane, release of
- enzymes that digest through egg jelly to egg surface
- ·
- Extension of acrosomal process, with
- species-specific bindin proteins recognized by species-specific egg receptor
- proteins
-
Define internal fertilization; explain why such fertilization requires complex adult
interactions, and why internal fertilization often results in the evolution of
intromittent organs?
- ·
- Internal fertilization- eggs fertilized inside F
- body
- ·
- Involved male-female courtship
- ·
- Male intromittent organs used to transfer sperm
- into female
-
Define courtship. What are some examples of courtship in insects?
- ·
- Courtship- intersexual information exchange –
- via visual, chemical, and/or mechanical signaling
-
Be able to define and distinguish oviparous, ovoviviparous, and viviparous
- ·
- Oviparous- F lays fertilized eggs into
- environment
- ·
- Ovoviviparous- eggs retained in body during development,
- embryos deriving nourishment from egg yolk
- ·
- Viviparous- fertilized egg retained in body,
- embryos deriving nourishment directly from mother
-
Define development. What are some major “landmarks” during animals development?
- ·
- Development: continuous process involving
- progressive changes in an individual from fertilization to maturity
- ·
- Zygote subdivides determinants partitioned in
- blastomeres (cleavage)
- ·
- Germ layers form (gastrulation)
- ·
- Body organs form, cells interact, differentiate
- (organogenesis)
-
Distinguish spiral, determinate from radial, indeterminate cleavage. Which major clades of
animals have these corresponding types of development
- ·
- Radial and indeterminate cleavage is ancestral
- in bilaterians – found in all seuterostomes, some protosomes
- ·
- Spiral and determinate for protostome
- development
-
Define gastrulation. What are the characteristics of embryos at the end of
gastrulation?
- ·
- Gastrulation- blastomeres differentiating into
- specific types of germ cells (forming embryonic germ cell layers)
- ·
- At end of gastrulation, embryonic body plan in
- place:
- o
- Cells have specific positions & cell
- neighbors
-
What is the “paradox of nuclear equivalence”?
- ·
- Blastomere nuclei are genetically equivalent,
- but ultimately develop into very different types of cells
-
What are 2 main factors that influence differential gene expression during animal
development? Be able to explain these.
- ·
- Cytoplasmic determinants
- ·
- Cell induction (cell-cell interactions)
- ·
- Serve to activate different combinations of
- genes in different cells
-
HOX genes are important in animal evolution. As an example, know how the Ubx HOX
gene impacts wing development (and ultimately wing evolution) in flies.
- ·
- HOX genes- transcription factors with 180-bp
- homeobox binding domain
- ·
- Different HOX genes expressedin different cells
- of developing embryo, regulate the expression (+/-) of many other genes
- (developmental regulatory genes)
- ·
- Ubx expressed in third thoracic segment (T3) of
- flies, represses expression of a gene which generates wing tissue
-
What are the basic requirements of all animal cells?
- ·
- Input- sugars, amino acids, oxygen
- ·
- Output- carbon dioxide, nitrogenous wastes
- ·
- Maintain- water, salt balance
-
How does surface area to volume ratio vary with cell size? Why are animals made up
of many small cells, versus fewer, large cells?
- ·
- The larger a cell the smaller the surface to
- volume ratio
- ·
- The smaller the cells the larger surface area to
- volume they occupy, large SV ratio necessary for effective materials transport
- (input & output)
-
3 primary factors interact to influence how animals get materials to and from all
cells in the body- what are these?
- ·
- Body organization (cell layer complexity ) ->
- reflects phylogeny
- ·
- Environment (aquatic vs. terrestrial)
-
How do sponges get materials to cells? What about Cnidaria (examples of a
diploblastic animal)? Platyhelminthes?
- ·
- Sponges are aquatic with porous bodyplan which
- allows water to flow thru body
- ·
- Cnidarians- aquatic with GV cavity sometimes
- greatly subdivided (ex. Extends into tesntacles) all cells of body in contact
- with GV fluids or external fluid medium
- ·
- Platyhelminthes- branched gut in aquatic or
- moist terrestrial habitats
-
What are the constraints of the Sponge/cnidaria “materials exchange” design?
- ·
- Must be aquatic, or if terrestrial restricted to
- moist habitats
- ·
- No party of the body can be more than few cell
- layers thick
- ·
- Limited “complexity” with these solutions
-
What is internalization?
- ·
- Internalization- cells exist in internal
- environments that is different from external environment
-
What are the 4 major organ systems that most bilaterians possess, and the functions
of these systems?
- ·
- Digestive system- food, salts, water in
- ·
- Respiratory system- oxygen in, carbon dioxide
- out
- ·
- Excretory system- nitrogenous wastes out,
- maintains salt & water balance
- ·
- Circulatory system- transport system
-
Provide an example of an animal with absorptive nutrition. How does such an animal gain
nutrients?
- ·
- Cestodes (platyhelminthes)- lack digestive
- system
- ·
- Absorb organic molecules digested by host
- digestive system
-
What are the 3 main modes of ingestive feeding in animals?
-
What does it mean to feed on particulate matter, what are the 2 primary ways of such
feeding? What is plankton?
- ·
- Particulates- (microscopic organinc “stuff”)
- suspended in water column
- ·
- Suspension feeders and deposit feeders
-
Suspension feeders use several means to feed- provide an invertebrate animal example.
Provide an invertebrate animal example for a deposit feeder.
- ·
- Suspension- marine annelids (use of flagella or
- cilia to produce current), barnacles (sweep feeing organ), foragers
- ·
- Deposit- marine polychaetes (pass sediment
- through body removing nutrients)
-
What are 4 categories of animal “macroscopic feeders”?
- ·
- Detritivores- eat “dead stuff” (and feces)
-
Why are detritivores ecologically important on land? What are 3 “services” provided
by dung beetles that are valuable in the cattle industry?
- ·
- Free up chemicals & minderals for future use
-
Invertebrate animals have evolved many special adaptations for predation- provide 2 specific
examples.
- ·
- Sticky aerial nets- spider webs
- ·
- Venoms- for stunning, paralyzing, killing prey
- (and defense)
-
Bilaterian digestive systems are regionally-specialized- what are 2 different process that
occur in different regions of the alimentary canal?
- ·
- Mechanical digestion (crushing food, chewing)
- ·
- Extravellular chemical digestion
-
What are the specific functions of animal circulatory (= transport) systems? What
are the 3 major types of circulatory systems seen in animals?
- ·
- Function: to transport respiratory gases,
- nutrients, excretory products, hormones to/from interstitial fluids
- o
- Lacking (ex. Sponges, cnidarians,
- platyhelminthes) cells in approximate contact w/ external medium, GV cavity, or
- branched gut
- o
- “closed” circulatory system
-
Some animals (including some triploblasts) actually lack a circulatory system – give
an example. How is “materials exchange” accomplished in such an animal?
- ·
- Ex. Sponges, cnidarians, playhelminthes
- ·
- Material exchange from GV cavity or directly
- into external medium
-
How does a “closed” circulatory system differ from an “open” circulatory system?
Which system provides more efficient blood flow?
- ·
- Closed- blood plasma circulates in narrow vessels
- & ultimately to capillaries propelled by heart (blood plasma remains
- largely separate from interstitial fluid)
- ·
- Open- no distinction between blodd &
- interstitial fluids (together called hemolymph)
-
Define external respiration. What are 2 primary characteristic of all metazoan
reparatory surfaces?
- ·
- Exchange of oxygen/carbon dioxide between whole
- organism & environment
- o
- Respiratory surfaces characterized by large
- surface areas
- o
- Respiratory surfaces are moist (respiratory
- gases must diffuse across aqueous boundary)
-
How does aerial breathing differ from aquatic breathing?
- ·
- More oxygen molecules in air (20-40 X more)
- ·
- Oxygen molecules diffuse about 10,000 times more
- rapidly in air than in water
- ·
- Aquatic breathers must be efficient at removing
- oxygen from water, expend more energy doing so
-
What are the 4 different types of animal respiratory systems discussed in class? Be
able to discuss how these work, and give specific animal examples for each.
- ·
- Cutaneous respiration- gas exchange by direct
- diffusion across body surface
- o
- Ex. Flatworms, earthworms, other very small
- animals
- o
- Only works in aquatic or moist terrestrial
- habitats
- o
- Often used in combination with other types of
- respiration
- ·
- Gills- thin walled extensions (evaginations) of
- the surface of aquatic animals
- o
- Typically highly branched or folded (increases
- surface area)
- o
- Gills either external (facilitates ventilation)
- or internal (greater protection)
- ·
- Lungs- internal air filled sacs with large
- surface areas, often ventilates
- o
- Evolved for respiration on land-> lung
- internalization related to water conservation in terrestrial habitats
- ·
- Tracheal systems- air filled cuticular tubes
- that branch throughout body of terrestrial arthropods (ex. Insects and some
- spiders)
- o
- Largely supplants gas transport role or
- circulatory system
-
Why is lung internalization so important?
- ·
- Water conservation for terrestrial living
-
What are 2 primary functions of excretory systems?
- ·
- Maintain salt & water balance (~constant
- intracellular environment)
- ·
- Rid cells & body of toxic nitrogenous wastes
- resulting from cellular metabloism
-
Define osmosis. Why does osmosis affect the salt and water balance of intracellular
environments?
- ·
- Osmosis: passive diffusion of water molecules
- across selectively permeable membrane in response to differing solute
- concentrations
-
Be able to distinguish the different osmolarities of extracellular fluid
enviornments (i.e., hypotonic, isotonic, hypertonic).
- ·
- Hypotonic- relatively low solute outside (water
- enters cell = cell burst)
- ·
- Isotonic- equal solute concentration inside
- & outside
- ·
- Hypertonic- relatively high solute outside
- (water leaves cell = cell shrivel)
-
How do excretory systems control the osmolarity of extracellular fluids?
- ·
- Filtering interstitial fluids
- ·
- Active secretion and resorption of specific ions
- (“solutes”)
-
What does it mean to say that most marine invertebrates are osmoconformers?
- ·
- Osmoconformers- osmolarity of interstitial
- fluids match that of external aquatic environment
-
When we talked about invertebrate animals, we discussed several “useful
biomolecules” (i.e. molecules with potential positive impacts on human
well-being)/ provide 2 examples of such molecules.
- ·
- Sceotrin- (marine natural compound in sponges)
- inhibits cell motility in a variety of cancer cell lines
- ·
- Prialt- (comes from slugs) primary alternative
- to morphines is non-addictive & anti-tolerant
-
Why is species “value” best considered “unpredictable”?
- ·
- Because no one can guess what we may discover
- from and organism and the beifits they may hold for us
- ·
- Ex. Patent of stable DNA polymerase from
- thermophilic bacterium is now wothr $200 million per year
-
What are current and projected levels of species extinction?
- ·
- Currently 1,000 times the avg and expected to
- raise to 10,000
-
What are the 5 primary causes of species extinction?
- o
- Invasive species & diseases
-
How large is the human population currently (approximately)? Predicted size in the
year 2050?
-
Define “ecological footprint”.
- ·
- Amount of land/shallow sea needed for food,
- water, housing, energy, transportation, commerce (measure of how consumptive
- people are…)
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