151 terms

Biology Unit 2


Terms in this set (...)

Bilateral animal without a coelom
All animals with keratinized skin have Internal or external fertilization?
Central nervous system (CNS)
Bilateral animal with a ganglia or brain and spinal cord
formation of the head where sense organs and a mouth are clustered
Flagellate feeding cell in choanoflagellates and sponges
animal whose body develops with 2 embryonic tissues (ectoderm and endoderm)
Large lineage of protostomes that grow by shedding an exoskeleton. Includes arthropods, nematodes, and other
Animal tissues consisting of sheet like layers of tightly packed cells that line an organ, gland, duct, or body surface
Extracellular Matrix (EMC):
meshwork in which animal cells are embedded, consists of proteins and polysaccharides made by cells
Are a spore, gamete, sporophyte, and gametophyte haploid or diploid? What is their cycle?
Haploid: spore, gamete, gametophyte Diploid: zygote, sporophyte Sporophyte goes through meiosis to produce spores, which go through mitosis to become gametophytes, which go through mitosis to become gametes, which are then fertilized to become zygotes, which then go through mitosis to become sporophytes. Meiosis happens from 2n to 1n. Mitosis is from 1n to 1n. Fertilization is 1n to 2n.
Major lineage of protostomes that grow by extending size of skeletons. Many have a specialized feeding structure or ciliated larvae.

Include Mollusca, platyhelimenthes, and annelids
Nerve net:
neurons are diffused throughout body without a ganglion
Pseudo coelomate:
coelom only partially lined with mesoderm
Stiff spike of CaCo provides structural support in body of sponges
Body develops 3 embryonic tissue layers (ectoderm, mesoderm, endoderm)
Cells dividing and creating blastopores to create the embryonic tissue layers
An opening in the surface of early embryos through which cells move during gastrulation
Approximately how many different animal species are alive on Earth currently. Approximately what percentage of those species have been described and given scientific names?
Roughly 1.8 million species have been named and at least briefly described, there are 3-100 million species total
What four key traits do all animals share? What distinguishes animals from fungus?
a. Multicellular, heterotrophic, collagen, cells absorb the food (not engulfing)
b. Have notochord, post-anal tail, dorsal spinal chord, pharanygeal gill slits
c. store carbs as glycogen not starch
What data is used to study the evolution of animals? Are animals monophyletic or paraphyletic? What evidence supports this conclusion?
a. Know by fossils, comparative morphology (visible and skeletal shape), and comparative genomics, most reproduce sexually
b. Animals are monophyletic
What evidence is there that multicellularity originated in a sponge-like animal? What Protist is the closest relative to animals?
a. Sponges have specialized cells that share characteristics with the Protist choanoflagellas
b. Both sponges and this protist are sessile, filter feed, and are genetically closely related
c. Choanoflagellas
Compare and contrast choanoflagellates and sponges. How do these organisms feed? How do they move? What structure(s) are found in sponges, but not choanoflagellates?
a. Choanoflagellates: single celled protists
b. Both: sessile, filter feed, have nuclei, don't have tissue, use choanocytes to trap food
c. Sponges: animals. Once considered colonies of single celled protists, but sponges will reassociate, multicellular
What are the basic molecular processes in the "Tool kit" of developmental genes?
a. Cell specialization
b. Regulation of cell cycling and growth
c. Adhesion among cells, and between cells and ECM
d. Recognition of self and nonself
e. Innate immunity
f. Developmental signaling and gene regulation
g. Programmed cell death
What are the 3 embryonic tissue layers called? What adult tissues are formed from each of these 3 layers?
Ectoderm-Skin and nervous system
Endoderm-Lining of digestive tract
Mesoderm-Circulation system, muscle and internal structures
Compare and contrast bilateral and radial symmetry. Give examples of animals of each type of symmetry. Which type of symmetry is most common in sessile animals?
a. Bilateral: Divided into 2, 3 body layers, cephalization, better input of environment with all senses in one main location which then allows for better mobility for prey and predators
i. vertebrates
b. Radial: Same all the way around, only 2 body layers, most common in sessile animals, can't be snuck up on, can observe the environment all around it
i. Jellyfish
Compare the nervous system found in sponges, cnidarians and earthworms. Can you train a jellyfish? Why or why not?
a. Sponges: No nerves
b. Cnidarians: Nerve net, work on hormones
c. Earthworms: Central nervous system with a ganglion
d. Can't train a jellyfish because it doesn't have a ganglion
What is cephalization and why is cephalization an adaptation for movement?
Formation of brain and senses. Allows for more effective movement as all senses are located in one are to have a better observation of the environment around it
Describe the basic bilateral body shape. Which germ layer forms the inner tube? Which forms the outer tube?
A tube within a tube. The inner tube is the gut (endoderm), surrounded by a mesoderm, surrounded by the skin and nervous system (ectoderm)
What is a coelom? Why is a coelom a significant innovation?
a. Body cavity lined with mesoderm
b. Coelom is significant because provides a space for oxygen and nutrients to circulate. Enables the internal organs to move independently of each other.
Draw a cross section of an acoelomate, pseudocoelomate, and coelomate
Hydrostatic skeleton
coelom surrounded by muscles, no bones
Compare and contrast protostome and deuterostome development from zygote to gastrulation. Does the blastopore become the mouth or the anus in a protostome animal?
a. After gastrulation. If blastopore becomes a mouth, its protostome. If blastopore becomes an anus, it's a deuterostome. Before this everything is the same:
b. A zygote goes through cleavage until it's a morula, which then becomes a Blastula: hollow ball of cells that gets one end punched in through gastrulation
What is segmentation and why is it such a successful body form?
a. Rings in earthworms, sections of arthropods, hind quarters vs. front of tetripods. Data suggests that these arose early and are homologous, but vertebrates are not homologous
b. Successful because the small changes of appendages and segments result in various novel numbers, shapes, and sizes. Interesting because appendages are diverse, not all the same
What was the Cambrian explosion? Why do scientists think there was such a radical diversification of body plans approximately 500 million years ago?
a. Explosion of land plants, higher O2 meant more energy per fuel molecule, means you can build more complicated structures like aerobic respiration
b. Evolution of predation, selection pressure forced evolution and diversification. New niches beget new niches, diversification creates new niches
c. Evidence of a wide diversity of animal body plans in the fossil record
Describe three different sensory adaptations that are found in animals (beyond the basic 5 humans have).
a. Magnetic field: detect this and use it for navigation
b. Electric field: detect electrical activity in muscles of passing prey
c. Barometric pressure: Birds can avoid storms by sensing changes in air pressure
Compare and contrast detritivores, herbivores, carnivores, and omnivores. Give examples of each.
a. All heterotrophs, getting carbon not from CO2
b. Herbivores: eat plants (turtles)
c. Carnivores: eat meat (tigers)
d. Omnivores: eat meat and plants (humans)
e. Detritivores: eat dead organic matter (millipedes)
f. This is how we organize stuff into food chains
Describe 4 general feeding strategies used by animals. Give examples of each strategy.
a. Suspension: filter feeders
i. Sponge
b. Deposit: Ingest organic materials deposited on a substrate
i. Typically, in ocean feeding on detritus snow. Example is sea cucumbers
c. Fluid: Sucks or mops up liquids like nectar or sap
i. butterfly
d. Mass: take chunks of food into mouth
i. Lion
Why is locomotion important to an animal? Are animal appendages the result of convergent evolution or homology? What is the evidence for this?
a. Locomotion allows animals to feed and accomplish more complicated features than sessile animals
b. Legs are homologous
c. Evidence:
i. Legs have the same gene product, just different hox genes. These genes are ancestral, they just varied as species diverged
Do all animals fertilize eggs inside the female's body (During sexual reproduction)? How can you most effectively influence generations? Which habitats have a lot of animals that reproduce via external fertilization?
a. Most reproduce sexually via meiosis and fusion of gametes. However, some species reproduced only asexually because its more efficient but less diverse. But some can produce either way depending on the environment
b. A zygote goes through cleavage until it's a morula, which then becomes a Blastula: hollow ball of cells that gets one end punched in through gastrulation
c. Fitness means leaving the most offspring, so the most direct way to influence generations is to diversify traits through sexual reproduction
d. External fertilization is common in aquatic environments
Draw an animal life cycle that includes a juvenile, larval and adult stage. Direct vs. indirect development? Do all animals complete metamorphosis?
a. Figure 33.14
b. Direct development: new born look similar to adults
c. Indirect development: metamorphosis, larvae look completetly different
d. Only indirect animals go through metamorphosis
Compare and contrast Porifera and Cnidaria. How do each eat, reproduce and where do each live?
a. Porifera- Mostly suspension feeders, adults are sessile, asexual in a variety of ways, some sexual but rarely self fertilize, larvae swim using cilia

b. Cnidaria-Feed by cnidocyte-Tentacles, budding-new individuals grow outside the body or fission-body splits in half, live in ocean mostly anywhere from surface to the bottom. Sexual and asexual
i. Some in freshwater, most are marine, radically symmetrical, only 2 body layers (diploblast), have a mesoglea, have gastrovascular cavity, no mesoderm, incomplete digestive tract, have tissues, diploid
Draw a medusa and a polyp, labeling the endoderm, ectoderm, and gastrovascular cavity.
Is mesoglea a form of mesodermal tissue? Why or why not? What synapomorphy defines the group (Cnidarians)? Are polyps haploid or diploid? Are medusa haploid or diploid?
a. Mesoglea isn't a form of mesodermal tissue because its a largely noncellular layer composed of a jellylike material permeated by a complex network of supporting fibres that may be microscopically thin or very thick
b. Cnidarians are defined by mesoglea
c. Polyps are diploid
d. Medusa are diploid
e. Only haploids are eggs and sperm
Any heritable trait that increases the fitness of an individual with that trait
Annelida? Coelom? complete or incomplete digestion? Respiration? Closed or open circulation?Asexual or sexual reproduction? Symmetry?
Distinguished by a segmented body and a coelom that functions as a hydrostatic skeleton. Belong to lophotrochozoan branch
a. Details
i. Digestion: Complete
ii. Respiration: Breath through skin
iii. Reproduction: Sexual by copulation or hermaphroditic
iv. Circulation: closed
v. Coelom
vi. Symmetry: bilateral
Arthropoda? Digestion? Reproduction? Respiration? Circulation? Coelom? Symmetry?
Segmented body, hard jointed exoskeleton, paired jointed appendages, and a hemocoel. Belong to ecdysozoan branch
i. Digestion: Complete
ii. Reproduction: Sexual external fertilization
iii. Respiration: gills for aquatic and tracheal for terrestrial
iv. Circulation: open
v. Hemocoelom
vi. Symmetry: Bilateral
Mollusks that have shells made of two parts or valves (ex. Clams and mussels)
Lineage of mollusks including squids, octopuses, and nautiluses. Have large brains, excellent vision, tentacles, and reduced or no shell
Pair of claw like appendages found around the mouth of certain arthropods
Polysaccharide composed of N-acetyl-glucosamine monomers joined end to end by glycosidic linkages. Found in cell walls of fungi and algae and external skeletons
Lineage of arthropods (shrimp, lobster, crabs), have a carapace, and mandibles for biting and chewing
Lineage of mollusks, have a foot and a radula. (slugs and snails, nautilus)
hemimetabolous metamorphosis:
Animal increases in size from one stage to another, but doesn't dramatically change its body form. Incomplete metamorphosis
Body cavity in arthropods and some mollusks. Contains a pool of circulatory fluid surrounding the internal organs. Not lined in mesoderm
class of hermaphroditic aquatic, terrestrial, or parasitic annelid worms distinguished by a coelom reduced to a series of vascular sinuses, sucking disk, and absence of parapodia and setae (hairlike bristles). Example: Leeches
Holometabolous metamorphosis:
Animal completely changes its form, includes a larval stage. Complete metamorphosis
Used in suspension filter feeding
The thick outer tissue that protects the visceral mass and may secrete a calcium carbonate shell
Mollusca digestion? Respiration? Reproduction? Circulation? Coelom or nah? Symmetry?
a. Details
i. Digestion: Complete
ii. Respiration: gills
iii. Reproduction: Sexual
iv. Circulation: open
v. Coelom
vi. Symmetry: bilateral
Method of body growth used by ecdysozoans, involves shedding of an external protective cuticle or skeleton, expansion of the soft body and growth of the new external layer
Nematodes? Coelom? complete or incomplete digestion? Respiration? Closed or open circulation?Asexual or sexual reproduction? Symmetry?
Distinguished by an unsegmented body with a pseudocoelom and no appendages. Belong to the ecdysozoans, roundworms
Digestion: complete
Respiration: through the skin
No circulatory system
Reproduce: Sexually, some hermaphrodite
Symmetry: Bilateral
any hermaphroditic terrestrial or aquatic annelids (as an earthworm) that lack a specialized head
Platyhelminthes? Digestion? Respiration? Reproduction? Circulation? Coelom? Symmetry?
Flatworms, distinguished by a broad, flat, unsegmented body that lacks a coelom. Belong to lophotrochozoan branch
a. Digestion: Parasitic, incomplete
b. Respiration: Breath through the skin
c. Reproduction: sexually reproduce or asexually reproduce. It can either fertilize it's own egg and give birth to those eggs later, or detach a piece of itself from its body and let adult stem cells do the work of creating a new planeria
d. Circulation: None
e. Acoelomate
f. Symmetry: bilatral
chiefly marine annelid worms (as clam worms) usually with paired segmental appendages, separate sexes, and a free-swimming trochophore larva
Include about 600 extant species. Entirely marine, they inhabit hard bottoms and rocky coasts in all of the world's oceans
Rasping feeding appendage in mollusks such as gastropods
Prominent body regions in arthropods like the head, thorax, and abdomen in insects
water-dwelling, eight-legged, segmented micro-animals
class within the phylum Platyhelminthes. It includes two groups of parasitic flatworms, known as flukes. They are internal parasites of mollusks and vertebrates
Larvae with a ring of cilia around its middle that is found in some lophotrochozoans
most primitive group within the phylum Platyhelminthes
bilateral symmetry
solid because all the space around their digestive cavity is filled with muscle and other tissue.
No respiratory or circulatory system, exchange gases by diffusion through all their cells.
Have a muscular mouth, called a pharynx, as well as a saclike digestive cavity.
Osmoregulatory system, the protonephridium, made up of tubules, and flame cells.
Visceral mass:
Contains most of the internal organs and external gill
In your own words, define protostome. Are protostomes monophyletic or paraphyletic? Are all protostomes coelomate? Do they all have bilateral symmetry? Explain.
a. Coelomates, mouth forms first, blastopore becomes mouth
b. Monophyletic
c. Not all are bilateral
d. Nearly ubiquitous
Compare and contrast Lophotrochozoa and Ecdysozoa.
a. Lophotrochozoan: mollusks, annelids; larvae are trochophore
b. Ecdysozoa: arthropods and nematodes; all undergo ecdysis, molting exoskeleton
Are most animal's protostomes or deuterostomes? What 2 groups make most protostomes?
a. Most animals are protostomes
b. Ecdysozoa and Lophotrochozoa
How do protostomes affect humans? Describe the ecosystem services provided by protostomes? What two model organisms are protostomes?
a. Can be carnivores, detrivores, herbivores
b. Pollinate our world
c. In soil preparation worms put nutrients in the soil
d. Provide valuable materials like silk, honey, pearls
e. Model organisms: fruit flies and cielegans
f. Are common parasites and transmit human disease
How did the transition to land open a new adaptive zone? What three challenges did the early land protostomes have to overcome? Give specific examples of adaptations used to meet these challenges?
a. Important because opened up new habitats and resources to exploit, adaptive zone with new traits to survive

b. Challenges:
i. Effective gas exchange in the air, not in water
1. Example: lungs instead of gills
2. Roundworms have high surface to volume ratio

ii. Resist drying out
1. Example: mucus on snails
2. Insects evolved a waxy layer (cuticle)
3. Environment resistant eggs

iii. Support body weight out of water
1. Example: legs
The developmental "tool-kit" genes are found in most mammals. How do we have such diverse body plans in animals?
a. Well conserved, means if bilaterally symmetrical the animal will have a head and tail, similar to others with same symmetry
b. Hox genes, while similar, aren't identical
c. May only use certain genes, may not be expressed in same location or not expressed at all while others are, turned on if in a certain environment
d. Genes may be different due to adaptation
Do flatworms (Platyhelminthes) have a coelom? Was there coelom lost or are they a phylum that branched off before coeloms formed in other groups?
No, had one, didn't use it, so they lost it
How do the mouth parts of suspension feeders differ from those of deposit or mass feeders?
a. Suspension: feathery and capture
b. Deposit: long sticky tentacles
c. Mass: sharp fangs to impale prey
Draw a mollusk body plan
Compare and contrast open and closed circulatory systems. Which animals have open circulatory systems (2)? Which have closed (2)? What is a hemocoel?
a. Open: heart that serves as a pump with vessels that go out, hemolymph gets squeezed out to bathe tissues. Vessels are not enclosed, just let the blood run over tissues without veins to enclose it. Don't have blood and lymph, only hemolymph (clear with a hint of red)
i. Mollusca, arthropods
b. Closed: blood is not bathing the tissue, capillaries weave through tissues, enclosed in veins to deliver oxygen and nutrients. Closed system with tubes connected to the heart. Actually get blood and lymph (tissue fluid)
i. Vertebrates, annelids
c. Hemocoel: a body cavity (as in arthropods or some mollusks) that contains blood or hemolymph and functions as part of the circulatory system
What is the function of a radula? Which phylum of animals has a radula?
a. Unique tongue like organ, animals in phylum Mollusca have this
b. Function: like a piece of sand paper rubbed over food to break it down to then slurp it up
What are the four classes of Mollusca? Give an example of each. In what way are cephalopods unusual mollusks?
a. Bivalvia
i. Clam
b. Polyplacophora
i. chiton
c. Gastropoda
i. Slug
d. Cephalopoda
i. Octopus
ii. Unusual because it's the only class without a shell, carnivorous, fast moving, closed circulation, some color change, some change shape with color, some are toxic
Draw a planarian and label its gastrovascular cavity, eyespots, and pharynx. What function do flame cells perform?
a. Flame cells: line the surface of their skin, how they get rid of nitrogen waste, like a kidney
b. http://bio1152.nicerweb.com/Locked/media/ch33/33_10PlanarianAnatomy.jpg
Name the 3 classes of Platyhelminthes. Which are free-living and which are parasitic? Give examples of each.
a. Turbellarians: free living/nonparasitic
i. Typically, hermaphrodites
b. Cestodes: parasitic
i. Use scolex to attach to intestinal lining
c. Trematodes: parasitic
What are the 3 subgroups in annelids?
Polychaeates, oligochaetes, and Hirudinea
Leeches are annelids with a two-part bite. What do the chemicals in leech saliva do to the host? How are leeches used in modern medicine?
a. Hirudinea
b. Chemicals numb the skin so the prey doesn't notice the attachment and keeps the blood flowing
c. Used when reattaching an amputation
What traits do all ecdysozoans share? How do these influence the growth/life cycle of these animals? What two phyla are Ecdysozoans?
a. Cuticle and exoskeleton for protection and structure for muscle attachment, molts which is how these animals grow
b. Arthropoda and nematoda
What 3 characteristics do all arthropods share? Do arthropods have an open or closed circulatory system? What are the exoskeletons of arthropods made of?
a. Segmented bodies, chitinous exoskeleton, jointed limbs, hemocoel
b. Have an open circulatory system
c. Exoskeletons made of chitin
Compare and contrast hemimetabolous and Holometabolous metamorphosis. Would you expect a lophotrochozoan to undergo metamorphosis? Why or why not?
a. Lophotrophozoans don't undergo metamorphosis
b. Hemimetabolous: larvae are just small version of adult. incomplete
c. Holometabolous: larvae don't look like adult. complete
Why is complete metamorphosis more common than incomplete metamorphosis? What are the advantages of complete metabolism?
Complete is more common because being able to have multiple food sources doubles the range and amount of food the organism can get in each stage.
Advantages of functional specialization
What is the common name of Tardigrades? Why are they being studied in research labs?
a. Water bears, microscopic animals. Live in diverse marine, freshwater, and terrestrial environments. Hemocoel, lobe shaped legs, suck fluid from animals and plants, detrivores
b. Studied because they are extremophiles, trying to make sense of how animals developed
Why are nematodes considered pseudocoelomate instead of coelomate? What diseases do pinworms, Onchocerca, Wurchereria and Trichenella species cause?
a. Nematodes are unsegmented worms, tube within a tube body plan, no appendages, have cuticle that is molted during growth
b. Considered pseudocoelomate
c. Onchocerca: eye worm disease
Wurchereria bancrofti: elephantiasis
Trichenella: trichinosis
Pinworms: intestinal disease that cause itchy butt
Compare and contrast Insecta, Crustacea, and Chelicera. Give examples of each. Draw the basic body plan and label the tagmata found in each. What specialized structures are found in each group? What groups have antennae? Which undergo metamorphosis?
a. Insecta: extremely diverse in habitat, have head, thorax and abdomen, generally sexually reproduction w/ different sexes, but many are asexual with parthenogenesis, most undergo complete metamorphosis

b. Crustacea: have 2 sets of antennae, live mostly in marine +freshwater environments, 2 tagmata cephalothorax and abdomen, have a carapace, many pairs of specialized appendages, sexual reproduction with internal fertilization but eggs released when hatched, many species include a larval stage called a nauplius.

c. Chelicera: Arachnida, 2 tagmata (cephalothorax and abdomen), appendages include 4 pairs of legs, 1 pair of chelicerae (for feeding, defense, copulation, movement, or sensory), 1 pair of pedipalps (used in sexual reproduction), some are predators, some are parasites, some are detritus, digestion begins externally in spiders, reproduction is sexual with internal fertilization, extensive courtship displays, metamorphosis does not occur, no larval forms

i. Include sea spiders, horseshoe crabs, daddy longlegs, scorpions, mites, ticks, spiders
solution of water and protein found in amniotic eggs that nourishes the growing embryo
sac-like structure that forms part of a developing amniotes conceptus It helps the embryo exchange gases and handle liquid waste.
Amniotic egg:
Egg that has a water tight shell or case enclosing the membrane bound water supply, food supply, and waste sac
Innermost part of the membranes surrounding the embryo in an amniotic egg
Lineage of vertebrates, many of which breath through their skin and feed on land but lay their eggs in water. Represent the earliest tetrapod's (frogs, salamanders, caecilians)
group of limbless, serpentine amphibians. They mostly live hidden in the ground
1 of 3 lineages of chordates, small mobile organisms that live in marine sands and suspension feed (lancelets or amphioxus)
contains the cartilaginous fishes: they are jawed vertebrates with paired fins, paired nares, scales, a heart with its chambers in series, and skeletons made of cartilage rather than bone.
one of the membranes that exist during pregnancy between the developing fetus and mother (the fetal membranes). The chorion and the amnion together form the amniotic sac.
protects the brain of vertebrates, forms part of the skull
Dorsal hollow nerve cord:
hollow bundle of nerves extending from brain along the dorsal aide, cerebrospinal fluid inside a central channel. Defining structure of chordates
Lineage of deuterostomes distinguished by adult bodies with five sided radial symmetries, water vascular system, tube feet. (sea urchins, sea stars)
Chemical reaction that absorbs heat
lineage of mammals whose young develop in the uterus and not housed in an abdominal pouch (placental animals)
lost vertebrate characteristics
family of molecules, cells that make up our skin and inner structures are composed of 20 different types of keratin. Provide mechanical strength for cells to resist pressure and abrasion. Form fingernails, toenails and hair
Ancestor of the fist land dwelling vertebrate. Have limb like fins, have lungs to breath air, can walk short distances in shallow waters, can survive on land for short periods of time and believed to have evolved into the first land dwelling vertebrate with limbs
lineage of mammals that nourish young in a pouch after short development in uterus
lineage of mammals that lay eggs and nourish the young with milk (platypus and 4 echidna)
supportive but flexible rod in the back of a chordate embryo, ventral to spinal cord. Replaced by vertebrate in adults
stiff flap of tissue that covers the gills of teleost fish
Pharyngeal gill slits:
set of parallel openings from throat to the outside that function for feeding and gas exchange. In chordates
forms in pregnant uterus from maternal and fetal tissues. Delivers oxygen to fetus, nutrients and wastes between mother and fetus, anchors fetus to uterus wall, produces some hormones. In most mammals
Swim bladder:
gas filled organ of many ray finned fishes that regulates buoyancy
any member of vertebrates that have two pairs of limbs (birds, reptiles, amphibians, mammals)
one of the three chordate lineages
sessile or floating
filter feeders with a polysaccharide covering and 2 siphons.
Includes tunicates and salps.
Have pharyngeal gills
Water vascular system:
in echinoderms, a system of fluid filled tubes and chambers that functions as a hydrostatic skeleton
Yolk sac:
nutrient rich cytoplasm in an egg cell, used as food for the embryo
Are deuterostomes monophyletic or paraphyletic? Are echinoderms monophyletic?
What synapomorphies separate echinoderms from other groups of animals?
-radial symmetry
-water vascular system
Which group of animals has a water vascular system? How do sea stars (starfish) feed on bivalves? How does this differ from sand dollars and sea urchins?
a. Echinoderms
b. clamping onto each half of the shell with tube feet making endoskeleton rigid
-pulls shell apart and extrudes stomach from body
-discretes digestive enzymes inside shell
-absorbs small molecules released by enzyme
c. Sea urchins don't have tube feet, so just use jaw-like structure to scrape over surfaces to eat things that way
Four features found in ALL chordates? Do ALL chordates have these 4 traits throughout their lifetime? Explain.
a. -pharyngeal gill slits
-dorsal hollow nerve cord
-post anal tail
b. Not all chordates have these
What are the 3 major groups of chordates? Do all chordates have a backbone (vertebral column)? Explain.
a. -cephalochordates (lancelet)
-urochordates (tunicate; sea squirts)
b. Not all have a back bone, only vertebrates
What traits are unique to vertebrates? Are vertebrates a monophyletic group?
a. Monopheletic
b. Vertebrate jaw
c. Tetrapod limb
d. Amniotic egg
e. Placenta
f. Parental care
g. Wings and flight
Describe how the vertebrate jaw is an innovation that lead to the evolutionary success and diversity of vertebrates. How did the modern vertebrate jaw evolve? What evidence is there for this hypothesis?
a. Vertebrates couldn't harvest food by biting until jaws evolved, so brought new food sources
b. Jaws formed from the gill arches (curved regions of tissues between gills), animals with thicker gill arches were naturally selected until it was naturally selected to form into a jaw
c. Evidence:
i. Jaws and gill arches look a lot like each other, similar bony or cartilaginous morphology
ii. Muscles move both structures have same embryonic origin
iii. Both derived from neural crest cells
iv. Regulatory gene expression patterns are similar in both structures
Why are lungfish thought to be the closest living relative to amphibians? What evidence supports the hypothesis that tetrapod limbs evolved from fish fins?
a. Because they live in shallow, oxygen poor water. Have lungs instead of gills, some have fleshy fins supported by bones and are capable of walking short distances
b. The fleshy fins have muscles, tetrapod fossils provides trong links between limbs of ancestors of lungfish and earliest land vertebrate.
i. Supported by fossil record and molecular genetic evidence
1. hox genes produce proteins found in same times in development in the same location in both fleshy fins and tetrapod limbs
Draw an amniotic egg, label and describe the function of the chorion, albumen, allantois, yolk sac and amnion. Differentiate between the amniotic eggs found in birds and non-bird reptiles. Which vertebrates are considered amniotes? Is fertilization internal or external in amniotes? Why?
a. Non bird reptiles have a thicker shell, leathery, stiffened by calcium carbonate deposits
b. Birds have ones stiffened by extensive calcium carbonate deposits, more watertight and laid in nests exposed to air
c. Vertebrates that are able to lay amniotic eggs outside of water are considered amniotes
d. Fertilization is internal in amniotes
e. Draw: http://ksuweb.kennesaw.edu/~jdirnber/Bio2108/Lecture/LecBiodiversity/34_25AmnioticEgg-L.jpg
i. Chorion: allows gas exchange
ii. Allantois: contains waste
iii. Yolk sac: contains nutrients
iv. Amnion: contains embryo
v. Albumen: provides water and mechanical support
What other features of amniotes enable them to break their close ties to water and live on land?
a. Placenta
b. can keep eggs from drying out with a protective covering
Are animals with a placenta viviparous or oviparous? What is the function of the placenta? Which group of amniotes (mammals or reptiles or both) have a placenta? What are the advantages of having a placenta?
a. Viviparous
b. Facilitates o2 and nutrients to embryo, also removes wastes
c. Advantages:
i. Offspring have more constant temperature
ii. Offspring protected
iii. Offspring are portable, mothers aren't tied to a nest
What are the advantages and disadvantages of providing parental care? Which animals are known to provide parental care?
a. Mammals and birds are known to give further parental care
b. Advantage:
i. Extended care to make sure Social skills, hunting skills, feeding skills are all developed properly
c. Disadvantage:
i. Less offspring
What is the current hypothesis explaining the origin of feathers? What adaptations are found in birds that enable flight?
a. Began with simple projections from the skin and culminated into complex structures seen today.
b. Birds are from dinosaurs based on fossil evidence, living examples of dinosaurs
c. Feather fossils discovered early 2000s,
d. Adaptations:
i. Pretty colors in males to woo females in mating rituals
ii. Females have bland colors in order to be camouflaged enough to guard the nest without being spotted by predators
iii. Keel breast bone on sternum for attachment of flight muscles
iv. Produce heat in their tissues, endothermic
v. Hollow bones to provide a lighter weight and strengthened by struts
How are hagfish and lampreys different from most vertebrates? Which are scavengers and which are parasites?
a. Lack jaws
i. Lampreys are parasites
ii. Hagfish are predators
How do chondrichthyes differ from ray finned fish? How are they similar? How do sharks stay buoyant? How is this different from bony fish? Does this organism have a cloaca?
a. Ray finned fish have operculum, swim bladder, and bony skelton, have strongly flattened dorsal ventral body plane
b. Sharks: cartilaginous skeleton, no operculum or swim bladder, torpedo bodies. No swim bladder allows it to go up and down a lot faster than bony fish
c. Sharks have to swim to breath and to not sink, bony fish don't need to do this because they have a swim bladder. Don't have an operculum so have to move to filter in air, bony fish have an operculum that can do this for them. 2 chambered heart with closed circulatory system. Good smell, lateral line for pressure wave detection to "hear" prey. Only animal with a cloaca
Which group of fish have an operculum? Why is this structure an innovation?
a. Operculum: Covering over the gills. Bony fish have these, not sharks
b. Chondricthyes have an operculum, bony skeleton, and swim bladder for buoyancy
c. Makes breathing in water easy to do without moving
What are the 3 distinct clades of amphibian? What are the "2 lives" of an amphibian? Why are amphibians tied to water?
a. Monophyletic
b. Clades:
i. Frogs and toads
ii. Salamanders
iii. Caecilians, lack limbs and resemble worms or snakes
c. 2 lives: refers to the metamorphosis of amphibians (larval and adult forms)
i. Change of diet, breathing, and habitat
Are amniotes a monophyletic or paraphyletic group? What adaptations are found in amniotes that are not found in amphibians?
a. Amphibians need water to reproduce and to breath
b. Amniotes have a dry egg that doesn't need water
i. Keratin in skin and hair and nails/claws, waterproof protein
ii. Breath with better developed lungs, not through the skin like amphibians
iii. Embryo is in middle of embryonic egg, so fertilization is internal
Describe the 3 major groups of mammals. How do monotremes differ from marsupials? How do marsupials differ from placental mammals? What are the 3 characteristics that are found in ALL mammals?
a. Groups:
i. Monotremes: Platypus + echidnas
1. Lay eggs
ii. Marsupials: Marsupials
1. Have poorly developed placenta but well developed pouch for rearing offspring
iii. Eutherians: Placental mammals
1. Eutherians have well developed placenta and extended pregnancy

b. Characteristics:
i. Hair/fur
ii. Endothermy: regulate body temp with internally generated heat
iii. Mammary glands: gave mammals ability to provide young with extensive parental care (lactation, modified sweat glands)
1. Doesn't mean they have nipples. Platypi lactate through their fur so babies sucle on hair
How are turtles different from snakes? Which group has a kinetic skull? Why is this significant? What adaptations are found in crocodiles that allow them to wait for prey?
a. Turtles have hard protective shell, sharp beak but no teeth, shell is its spine so can't live without it
b. Snakes: vestigial leg and hip bones (lost their legs), kinetic skull
c. Kinetic skull: extremely mobile joints (detach jaw to eat large prey)
d. Crocodiles: have eyes on top of the head and nostrils on top of large snouts to be able to sit semi-submerged under water for extended periods of time. Way to stay hidden and sneak up on prey
Why were feathers an innovation for the first feathered dinosaurs?
a. Provide insulation
b. Are used for display for sexual selection and then camouflage when protecting young
c. Furnish the lift, power and steering needed for flight
d. Beaks determine what a bird can eat
What is sexual dimorphism? Which group of vertebrates has a significant variety of sexual dimorphism and complex mating rituals?
a. Dimorphism: Male and female look different
i. condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.
b. Birds have a variety of sexual dimorphisms
If you were to sequence the rRNA gene found in the DNA from a chloroplast from a plant cell and compare it to several different sources of DNA that are listed below, which would provide the closest match, based on your knowledge of the endosymbiosis theory?
RNA from cyanobacteria
Cephalization is an adaptation for...
Viviparous? Oviparous? Ovoviviparous?
e. Viviparous: live bearing
f. Oviparous: egg bearing
g. Ovoviviparous: egg-live bearing. Egg hatches inside the mom and then the mom gives a live birth
What is not a trait shared by all chordates at some point in their lives?