Zoology Final

5 Essential Characteristics of Science. Define 1 (10 pt)

1. guided by natural law
2. explainable by reference to natural law
3. testable against the empirical world
4. falsifiable
5. the conclusions of science are tentative and not necessarily the final word.
-this means that scientific discoveries are not considered absolute truth because they can be disproven at a later date. It's important because it means that scientists must be flexible and willing to set aside biases and assumptions.

What is the Scientific Method? Include the 7 steps and the distinction between absolute and relative truth. (5pt)

The hypothetic-deductive (scientific) method is a process by which scientists make discoveries and expand the body of scientific knowledge.
1) Observation
2) Question
3) Hypothesis
4) Prediction
5) Empirical Test (which involves a test and control group)
6) Conclusion (which either confirms or rejects the hypothesis)
7) Publication (where results are shared with others).

Absolute V Relative truth in science (5 pt)

Absolute truth does not exist in science because its conclusions are tentative! The scientific method is conducted with the understanding that conclusions based on test results could be expanded on or disproven later. Therefore scientific conclusions are considered relative truths, and are accepted for now, but will be dropped in favor of better, more accurate conclusions.

Define both hypothesis and theory, as used in science. Explain what the relationship is between a hypothesis and a theory. (10 pt)

Hypothesis: an (educated) potential explanation for a natural phenomena based on prior knowledge and observations.
Theory: a scientific hypothesis or set of related hypothesis that is very powerful in explaining a wide variety of natural phenomena and guides scientific investigation of those phenomena.
A hypothesis that is supported by a lot of evidence and is well established may attain the status of a theory (or remain a hypothesis).

2 Assumptions of Uniformitarianism (5 pt)

1) The principles of physics and chemistry haven't changed throughout earth's history
2) Past geological events that formed natural features occured through similar natural processes that we can observe today.

What idea of Malthus' helped Darwin formulate his theory of natural selection? (5 pt)

Malthus observed that animal and plant populations could grow beyond their environments' ability to support them with natural resources (carrying capacity).
This, combined with his study of pigeons made Darwin realise that a) such population growth would lead to a struggle for survival b) when organisms are struggling to make best use of natural resources for survival , those with favorable traits that helped them would be able to survive longer and reproduce more than those without those traits.

5 evolutionary theories (10 pt)

Multiplication of species
Perpetual change
Gradualism
Common descent
Natural selection

Types of Symmetry and the Planes (10 pts)

Spherical, Radial, Bilateral
Sagittal separates left from right
Frontal (coronal) separates dorsal from ventral
Transverse separates anterior from posterior

The two body plans and their developmental characteristics. (10 pts)

Protostome (1st mouth):
Spiral cleavage, mosaic embryo, blastopore becomes mouth, blastocoel forms schizocoely (by splitting)
Detuterostome (2nd mouth):
Radial cleavage, regulative embryo, blastopore becomes anus, blastocoel forms enterocoely (by outpocketing) for invertebrates and by a modified form of schizocoely for vertebrates.

Three body plans in reference to cavities. (10 pts)

Acoelomate: the mesoderm fills the blastocoel so there is no cavity.
Eucoelomate: the mesoderm lines the inside of the blastocoel on both sides. The cavity can be formed schizocoely (by splitting) or enterocoely (by outpocketing).
Pseudocoelomate: the mesoderm lines the outside of the blastocoel.

What is the difference between systemization and classification and why is it important in taxonomy? (10 pts)

Classification is the grouping of organisms by shared characteristics. The groupings cannot change or evolve.
Systematization is the arrangement into hierarchies of organisms by patterns of evolutionary ancestry and descent.
This distinction is important because the possesion of similar characteristics does not necessarily indicate shared ancestry. Taxonomy only uses systematization now.

Linnaeus' taxa in order (7 pts)

Kingdom Phylum Class Order Family Genus Species

The system for naming species: What is it called and what are its rules? (4 pts)

Binomial nomenclature
The genus is the first word and the first letter is capitalized.
The species epithet is the second word, and is all lowercase.
Both words should be either underlined or italicised.
There must be a unique combination for each species.

How does the biological species concept differ from earlier typological concepts? Why do evolutionary biologists prefer the biological species concept to the typological species concept? (5 points)

The typological concept dilineates species by morphology. It is fixed, and cannot change.
The biological species concept divides species by reproductive barriers, shared characteristics and common ancestry.
Evolutionary biologists prefer it because it accounts for evolutionary lineage, wheras the typological concept does not.

Explain the difference between homology and homoplasy. (5 pts)

Homology is the presence of similar characteristicswith similar embryonic origin that indicates a common ancestor.
Homoplasy/analogy is the presence of similar characteristics that does not indicate common ancestry.
This is important because similarity does not necessarily indicate common ancestry.

Three forms of relationship between taxonomic group and phylogenetic tree/ cladogram. (10 pts)

Monophyletic: includes the most recent common ancestor and all of its descendants. Accepted by both hypotheses.
Paraphyletic: includes most recent common ancestor and some of its descendants. Accepted by evolutionary taxonomy but not cladistics.
Polyphyletic: animals without recent common ancestor. Accepted by neither.

Three domains above the kingdom level.
Of the five traditional kingdoms, which 3 are accepted, and which two are not. (8 pts)

Eukarya, Bacteria, Archaebacteria
Accept: plantae, fungi, animalia
Reject: protista, monera

Define resolution as it is used in microscopy (5 pts)

Resolution is the smallest distance between two points on a specimen that can be distinguished. It dictates the limit of our ability to distinguish detail.

Explain excretion and osmoregulation in unicellular eukaryotes. (5 pts)

Excretion occurs via diffusion. Waste products diffuse through the membrane from a location with high concentration to one with low concentration.
Solutes suck water and if in freshwater unicellular eukaryotes have far more than the surrounding water. Water is continuously sucked in and it must be pumped out by contractile vacuoles to avoid swelling and bursting.

Cladorhizid feeding (5 pt)

Cladorhizids are predators. They are covered in hooked spicules which capture tiny crustaceans. The crustaceans are engulfed by cytoplasmic bacteria and digested by archaeocytes.

Explain the mechanism of nematocyst discharge. (10 pts)

Hydrostatic pressure is maintained but osmotic pressure is very high due to the concentration of solutes within the cnidocyst and the impermeablility of the membrane. When the cnidae is triggered, the permeability of the of the membrane changes, creating a hydrostatic pressure of 70 atmospheres which blows off the osculum and ejects the contents, discharging the nematocyst.

Classes of Phylum Platyhelminthes, 3 are always parasites, 1 are not (10 pt)

3: trematoda, monogenea, cestoda
1: turbellaria

Life cycle of *p. vivax* and malaria (8/10 pts)

The female mosquito ingests gametocytes which then burrow beneath the stomach lining. Male gametes fertilize female gametes, and the oocytes migrate to the salivary gland. The mosquito injects saliva into a human. The *plasmodium* migrate to the liver where they undergo schizogeny into sporozites which infect red blood cells and become gametocytes, which are then ingested by mosquitoes.

Name and briefly describe the three body types found in the sponges (porifera) (7/10 pts)

Asconoid: simplest forms.
have choanocytes lining spongocoel.
a single osculum
Syconoid: similar to modified asconoid.
choanocytes line canals.
Many oscula. Most belong to calcarea.
Leuconoid: most complex.
choanocytes line chambers.
No spongocoel.

Describe the lifecycle of the beef tapeworm *Taenia Saginata* including the means of infection. (8/10 pts)

Gravid proglottids are expelled in human feces and make their way into grass. The shelled larvae can survive for months without a host. Cows eat grass that houses larvae, which then enter the cow's muscles and encyst. Humans who eat beef that contains *Taenia saginata* and hasn't been properly cooked become infected, the tapeworm migrates to the intestines, where it can grow up to 7 feet and may release gravid proglottids for years, which are expelled in feces.

How does an entoproct differ from an ectoproct? (5 pts)

Both the mouth and anus are within the ring of tentacles in an entoproct. In an ectoproct the mouth is inside the tentacle ring, but the anus is elsewhere.

How does a typical bivalve feed and burrow into the sediment? (5 pt)

Bivalves are suspension feeders, so they draw in water through the mantle and over the gills. This filters out particles that the mollusc eats.
It burrows into the sediment by extending its foot and filling it with blood. It uses the foot to burrow deeper and when it is secure (with the posterior end above ground) it retracts the foot.

Why and how are annelid metamerism, hydrostatic skeleton, and muscles beneficial to locomotion? Why did we not see this before and why do we not see it in the nematoda or arthropoda? (10 pt)

The level of fluid in the coelemic cavity is constant, allowing segments to change shape. They have circular muscles that contract to make segments longer and thinner (stretching them forward), and longitudinal muscles that make segments thicker and shorter (anchoring them against the ground or burrow walls). T__**heir movement occurs by peristaltic contractions of these muscles.**__ No animals studied before annelids have hydrostatic skeletons. The nematodes are too highly pressurized and lack circular muscles and the arthropids cuticle is too thick and hard, preventing them from easily changing shape.

What characteristics of Annelids distinguish it from other phyla previously discussed? (5pts)

Metamerism (segmentation)
small and primitive brain
pair of nephridia in each segment
parapodia and gills for respiration
closed circulatory system

What is the economic importance of Annelids? (5 pts)

Act as food for organisms of interest to humans (fish).
Increase drainage and aeration of soils, help mix soil.
Leeches have medical uses.

Describe in detail earthworm mating. (10 pts)

At night, when it is dark and moist, earthworms stick their anterior ends out of their burrows and line up facing in opposite directions.
Mucus bands secreted by each worm's clitellum and ventral setae hold mating worms together.
Sperm are echanged and enter each worm's seminal receptacle.
The clitellim secretes a mucus tube and chitinous band that begins to slide down the worms' bodies.
Sperm eggs and albumin are released into the tube.
The tube slides off of the worms and the ends close. It is now a cocoon.
Fertilization and development occur inside the cocoons.
The offspring that emerges doesn't develop a clitellum until reproductive age.

Ascaris Lumbricoides. Large intestinal roundworm. (4/5 pts)

Female lives in intestine and releases eggs. Eggs exit host in fecal matter and contaminate soil/ water. __**Juveniles are resistant to direct sunlight, high temps.**__ *Enter hosts lungs, migrate to trachea, are coughed up into pharynx, are swallowed, enter esophagus, then mature in stomach and enter intestine where they feed on fecal matter and produce eggs.* __***Cause pneumonia, intestinal blockage, and intestinal perforation and coughing.***__

Hookworms (4/5 pts)

Have sharp, hooked mouthparts. Females can lay up to 200,000 eggs a day. __**Burrow thru skin to blood and enter intestine in a way similar to ascaris. Cause anemia, tiredness, and growth retardation in children.**__

Trichina worm (4/5 pts)

*Trichinella Spiralis* Cause trichinosis. Contracted from undercooked contaminated pork. Infect muscle cells and change gene expression so the cells lose their striations and become nurse cells that nourish the worm.

Pinworms (5 pts)

Cause little disease. Most common parasite in U.S. Live in the cecum of the sml intestine. Migrate to the anus at night, lay eggs, and cause itching. Y__**oung mature within 6 hrs at body temp.**__ Contaminate hands and bedclothes, are ingested adn migrate to intestine.

Filarial worms (5 pts)

*Wucheria Bancrofti* infect the lymphatic system, cause inflammation and obstruction of the immune system. Spread by mosquitos. Female worms release microfilariae into blood and lymph of host. Cause elephantiasis and river blindness.

Subphyla of Arthropoda.

Chelicerata, Myriapoda, Crustacea, Hexapoda

Chelicerata (3 pts)

6 pair appendages,
liquify food before consumption
simple eyes
no antennae or mandibles
One pair chelicerae, one pair pedipalps, 4 pair walking legs
Spiders, scorpions, mites, etc

Myriapoda (3 pts)

They have only one pair of antennae, mandibles, and maxillae. Legs are always uniramous
Each tagmata (except head) has at least 1 pair uniramous legs
Millipedes and centipedes

Crustacea (3 pts)

two pairs of antennae,
1 pair of mandibles, chelipeds
2 pairs of maxillae and antennae
3 pairs walking legs
All appendages except first pairs of antennae is biramous.
crabs, lobsters, etc

Hexapoda (3 pts)

six uniramous legs
distinct head, thorax, and abdomen
pair of antennae
mouthparts are modified for different food habits.
either have wings or had them in ancestral state
insects, butterflies, ants, etc

Arthropods in a hardened box. 2 import qs and how their answered (5 pts)

The exoskeleton.
1. How do they move.
Uniramous legs and segmentation.
Joints between segments and between legs.
2. How can they grow?
Molting. Arthropods molt the too small cuticle and grow a larger one that they can grow into.

Explain insect flight (10 pts)

Insects are the only invertebrates that can fly.
They have two pairs of membranous, scaled, or hairy wings which are either present, modified, or absent.
Direct muscles attached to the wings directly, change the angle of the wing during flight, allow the wings to twist in a figure 8 movement in order to adjust the thrust.
indirect muscles alter the shape of the thorax to power up and down strokes.
indirect muscles pull thoracic tergum down for upstroke.
downstroke is direct in some, indirect in others that arch the tergum
Neural control may be synchronous or asynchronous.

Three types of metamorphosis (10 pts)

Holometabolous (88% of insects):
separate stages for growth (larva), differentiation (pupa), and reproduction (adult)
Stages aren't in competition with each other.
Larva are usually wormlike ie caterpillars and maggots
They don't molt after reaching adulthood
Hemimetabolous:
Egg to nymph to adult.
Nymphs are usually small adults without wings or with non functional wings.
Some nymphs are aquatic and have acquatic adaptations (gills) ie dragonflies)
Direct Development:
Essentially egg to (small) adult.

Crustacean Molting (5 pt) +1 ec insect molting

Ecdysis occurs when molt-inhibiting hormone (produced by y organs in the eyestalks) stops being released, and molting hormone (produced in x-organs in eyestalks) is released. During pre-molt, inorganic salts and minerals are reabsorbed by the animal and the cuticle becomes thin and weak.
A new exoskeleton is grown underneath the old one, which is shed and eaten.
The animal expands with water or air to stretch out the new exosceleton and it grows until it fills the new one and needs to molt again.


Insects cease molting once they reach adulthood. Wings usually develop over successive instars.

5 classes of echinodermata and 1 other phylum, and two groups (8 pt)

Asteroidea, crinoidea, ophiuroidea, holothuroidea, echinoidea.
Hemichordata- pterobronchia and enteropneusta.

Pedicellaria (2 pt)

pincerlike protrusions on the surface of the skin of echinoderms

Madreporite (2 pt)

hard, stonelike opening to the water vascular system, located on the aboral side.

Cuverian Tubules (2 pts)

spaghtetti like internal organs of sea cucumbers, can be expelled to drive off or entangle predators.

Aristotle's lantern (2 pts)

masticating apparatus of sea urchins.

List and describe the 5 chordate hallmarks (15 pts)

1) Notochord: long hydrostatic organ that provides support
2)Endostyle (or analogous thyroid gland): secretes iodinated proteins in mucous that traps food.
3)Postanal tail: for locomotion in water
4) Dorsal tubular nerve chord: enlarges at anterior end to form brain, the basis of the nervous system.
5) Pharyngeal slits or pouches: initially for filter feeding, also for more efficient respiration.

2 living groups of jawless fish.
Living groups of fish with jaws:
Without bone (2 subgroups)
With bone ( 2 subgroups)
(8 pts)

hagfish and lampreys

Chondrichthyes- Elasmobranchii and aolocephali
Osteichtheys- Sarcopterygii and Actinopterygii

Countercurrent flow (6/10 pts) (more on paper study guide)

water flow ->
blood flow

3 living orders of modern amphibians (6 pts)

Caudata- salamanders and newts
Anura- Frogs and Toads
Apoda- Caecilians

Explain the shell layers of a mollusk. (10 pts)

Periostracum- outer layer. Made of conchiolin ( a protein). Protects inner layers from acid.
Prismatic/ intermediate layer- made of calcium carbonate
Nacreous layer- innermost. Gets thicker over time. As it is irritated by small particles like sand that are trapped inside, it builds layers of shell material around the particle, which becomes a pearl.

Explain the differences between cytoplasmic specification, conditional specification, and synctial specification. (10 pts)

Cytoplasmic specification: the single cells outside the embryo continue to grow differently. This leads to the mosaic embryo development.
Conditional specification: the cells wait for their positronal information from their neighbors.
Synctial specification: similar to conditional specification in that it diffuses within cytoplasm in single cells and not among other cells.

Name and distinguish the classes in phylum cnidaria. (10 pts)

Hydrozoa: Hydroids. Have both a polyp and medusa stage. Have a tubular shape with mouth inside the circle of tentacles facing upward. ex. hydra
Anthozoa: Sea anemones and corals. Have no medusa stage. Sessile lifestyle.
Staurozoa: Stalked jellyfish. Sessile and sedentary. Have adhesive discs to attach to seaweed. Medusa like resin on top of polyp.
Scyphozoa: True jellyfish. Medusa is dominant and free swimming.
Cubozoa: box jellyfish. Cube shaped. Medusa is dominant. Some species can kill humans in minutes.

Distinguish amoung Polyplacophora, Gastropoda, Pelecypoda (bivalves), Cephalopoda. (12 pts)

Polyplacophora: Chitins. Flattened dorsoventrally with 8 dorsal plates. Prefer rocky intertidal surface. Radula scrapes algae from rocks. Mantle extends around margin of plates.
Gastropoda: Most diverse class. Sluggish and sedentary lifestyles. Marine and terrestrial lifestyles ie snails.
Pelecypoda: Suspension feeders. 2 shells held together by hinge ligament, Large range in size (1-2 mm to giant south pacific clam), Clams, mussels, etc.
Cephalopoda: Active predators with circulatory systems. Have lost all or most of their shells. The foot is in the head region. Range from 2 cm to colossal squid.

Two other subphyla in chordata (10 pts)

Urochordata: tunicates. Have 5 chordate halmarks in larval stage. Divided into ascidacea, thaliacea, appendicularia
Cephalochordata: traditionally amphioxus, now under genus branchiostoma. Has all 5 chordate hallmarks as adults. Closed circulatory system but no heart.

Osmotic situation and osmoregulation of freshwater and marine bony fishes. (5 pts)

Freshwater: take in water and lose salt. lots of diluted urine to expell excess water due to lower solute concentration in water. Absorb salts thru special cells in epidermis and thru food. Need more salt, and need to get rid of excess water.
Marine: take in water and gain salt. Must expell excess solutes to osmoregulate due to high solute concentration in water. Need more water and less salt. Produce small amount of concentrated urine.

How do the three orders within amphibia differ from each other? (8/9 pts)

Anura: frogs and toads- tail is reabsorbed in adulthood. No scales. Unequal paired limbs. Jump as adults. Fused head and body.
Apoda: Caecilians- head, body, trunk. Scales present in some species. No tails or limbs. Burrowers, stay with their eggs.
Caudata: Salamanders and newts- no scales, elongated limbs, paired limbs are equal. Have a long tail.

4 differences btwn water and land, and the adaptations needed to survive the transition. (10 pts)

land has more terrestrial environments: rainforests, deserts, etc. Animals must adapt to them to survive.
Temperature regulation: water buffers the temp. On land, animals must adapt- skin creates less mucous- to retain water
Oxygen levels: 20x oxygen in air than in water. Animals developed lungs
Fluid density: 1000x air. 50x viscosity. Animals must adapt to bear their own weight.

How are the forelimbs of frogs diff from other vertebrates (2 pts)

They have 4 digits and are webbed- increases swimming efficiency

Three groups of adaptations that guided vertebrate evolution and how they contributed to the success of vertebrates (9 pts)

Musculoskeletal modifications
•Endoskeleton permits almost unlimited body size with much greater economy of building materials
•Segmented body muscles (myomeres) changed from V-shaped muscles of ancestral chordates to W-shaped muscles of vertebrates
Endoskeleton was composed initially of cartilage but later of bone
Phsiology:
•systems modified to meet increased metabolic demand
•With the origin of highly vascularized gills, function of pharynx shifted to primarily gas exchange
-Gut shifted from movement of food by ciliary action to muscular action
-Accessory digestive glands, the liver and pancreas, produced secretions that aided digestion
•Transportation of nutrients gases, and other substances was enhanced by Ventral 3-chambered heart, Erythrocytes containing hemoglobin
•Vertebrates possess paired, glomerular kidneys to remove metabolic waste products and regulated body fluid composition
New Head, Brain, and Sensory Systems
•Shift from filter feeding to active predation:
new sensory, motor, and integrative controls for locating and capturing prey
•Anterior end of nerve cord enlarged as a tripartite brain protected by cranium
•Paired special sense organs for vision, equilibrium, and sound evolved
•Other receptors that evolved chemical receptors, including taste and exquisitely sensitive olfactory organs,: lateral line receptors for detecting water vibrations: and electroreceptors for detecting electrical currents that signal prey

Respiratory tree (2 pts)

structures of sea urchins that serve for both respiration and excretion. empties into cloaca.

Papulae (2 pts)

aka dermal branchiae. Respiratory processes of sea stars.

Describe sea star development and metamorphosis (8 pts)

In most cases, embryonating eggs are dispersed in water and hatch to free-swimming larvae
Embryogenesis shows typical primitive deuterostome pattern
Main coelomic compartments, called somatocoels, arise from posterior blastocoel, Left hydrocoel becomes water-vascular system, Left axocoel becomes stone canal and perihemal channels
Free-swimming larva, bipinnaria, has cilia arranged in bands
-Ciliated tracts become larval arms
-Larva grows three adhesive arms and a sucker at the anterior
•Now called a brachiolaria
-Brachiolaria attaches to substrate and undergoes metamorphosis into a radial juvenile
Arms and tube feet appear, animal detaches from stalk and becomes a young sea star

4 types of fish scales (5 pts)

Placoid- cartilaginous fishes. Basal plate of dentine embedded in the skin and a backward pointing spine tipped with enamel.
Ganoid- nonteleost bony fishes. Thick bony rhombic scales. Not overlapping
Cycloid- teleost fishes. Thin, overlapping dermal scales. Smooth posterior margins.
Ctenoid- teleost fishes. Thin, overlapping scales. Exposed posterior margines have fine spines.

The liver fluke. Lifecycle, distribution, and means of infection. (10 pts)

Spreads via contaminated water sources.
Human excretes egg containing miracidium.
Snail eats egg. Miracidium hatches and mature into redia. Redia are expelled.
Matures to cercaria. Fish ingests cercaria.
Carcaria migrate to fish muscles. Form metacercarial cysts.
Human ingests undercooked contaminated fish. Migrate to liver and mature.

Frog v Tadpole

Frog: Jumps and swims
breathes with lungs and skin, no spiracle
carnivorous
tympanic membrane
terminal mouth placement
spinal column
3 heart chambers
urea waste
Tadpole: Unduatory mvmt
breathes with gills, skin, and spiracle
herbivorous
lateral line
ventral mouth placement
notochord
2 heart chambers
ammonia waste

The remaining chapters, those on this exam, compose the amniotes. They are divided into three lineages based upon their skull structure, namely the ___________________________, _________________________, and the _________________________. Of course one of the things that amniotes are known for is having an amniotic egg. Amniotic eggs contain four extraembryonic membranes which are the _________________________, _________________________, _________________________, and _________________________. (1 point each).

anaspid, diaspid, synapsid
amnion, allontois, chorion, yolk sac

There are a number of other adaptations or characters that are seen in the amniotes besides the amniotic egg that enables them successfully live on land. Discuss those attributes. (10 points

Rib ventilation of the lungs
-Thicker and more waterproof skin
Better-developed lungs than do amphibians:
more surface area, draw air into lungs by expanding the thoracic cavity
-Stronger Jaws
Fish jaws are designed for suction, which is not possible for terrestrial vertebrates. Expansion of the jaw musculature provided better mechanical advantage
-Efficient and versatile circulatory system and higher blood pressure than amphibians.
-Efficient strategies for Water-conservation: excrete their nitrogenous wastes as uric acid.
-Complex nervous system than amphibians.
Enlarged cerebrum- integration of sensory information. Good Vision, Olfactory highly developed, Vomeronasal organs

Why are "reptiles" as traditionally defined, a paraphyletic group? How has cladistics taxonomy revised Reptilia to make it monophyletic? (10 points)

Traditional Reptilia excludes birds but includes snakes lizards, tuataras, crocodilians, and turtles, plus some extinct groups of dinosaurs.
But birds and reptiles share common ancestors, skull characteristics, and beta keratin in the skin, making them a monophyletic group.
Crocodilians and birds are sister groups, more closely related than the crocodilians are to other
members of the reptilian lineages, they form a monophyletic group.
So cladistics includes the birds in the Reptilia because it makes it monophyletic rather than
paraphyletic.

Gender Determination in Reptiles

Some families of Turtles – low temperatures = males
high temperatures = females

All Crocodilians – low temperature = females, high temperatures = males

Lizards -high temps = females, low temps= males

Tell me about the rather unique senses that at least some snakes use. (5 points)

~Jacobson's organs
-Pair of pits in the roof of the mouth
-Lined with olfactory epithelium
-Forked tongue collects scent particles and conveys them to this organ
~Have pit organs with nerve endings sensitive to heat emitted by warm-bodied birds and mammals 0.003⁰ C

Flight of course is what we know birds for. What are the structural and functional adaptations that we discussed that are related to flight? (10 points)

•Wings are present
\-for lift and propulsion
•Respiratory system can take in oxygen when inhaling and exhaling
\-Must meet intense metabolic demands of flight
•Bones are hollow
\-Must provide a light but rigid airframe
•rapid and efficient Digestion and circulation

* digest and excrete food very quickly
•Nervous system
\-Complex sensory systems for headfirst, high-velocity flight
Feathers
* Toe locking mechanism
* Large kidneys, efficient filtration
* well developed brain, optic lobes, good hearing, fantastic sight (eye differences – fovea, more cones, or more rods, pectin)

How do marine birds rid themselves of excess salt?

Because the kidneys have a weak solute-concentrating ability, marine birds especially use extrarenal mechanisms to excrete the salts they gain from the food they eat and the seawater they drink. Salt glands located above each eye excrete a highly concentrated salt solution that runs out of internal or external nostrils giving them a perpetual runny nose.

How is flight accomplished?

Must generate lift in excess of their mass and to move forward.

Generate thrust to move against the resistive forces of drag

\-Wing is streamlined with a concave lower surface (cambered)

\-Leading edge of the wing has small tight-fitting feathers

\-Over two-thirds of the total lift comes from negative pressure from the airstream (flows longer distance over the top of the wing)

\-Lift-to-drag ratio determined by angle of attack and airspeed

What adaptations do some wings have to prevent stalling?

\-Stalling is delayed or prevented by a wing slot along the leading edge to direct rapidly moving air across the leading surface

\-In some birds the alula, or group of small feathers on the "thumb," provides a midwing slot

What are the four types of wings found in birds and how do they differ from each other? ( 4 pt)

\+Elliptical Wings

\-low-aspect ratio

\-alula and slotting between primary feathers to prevent stalling at low speeds, etc.

+High-Aspect Ratio = High-Speed Wings

\-sweep back and taper to a tip

\-Reduces "tip vortex" turbulence

\+Dynamic Soaring Wings = Active Soaring

\-long, narrow wings

\-lack wing slots and allow high speed

\-high lift and dynamic soaring

\+High-Lift Wings = Passive Soaring

\-slotting, alulas and pronounced camber

\-high lift at slow speed

\-broad, slotted wings allow sensitive response for static soaring

Mammalian Integumentary Glands (10pts)

Sweat glands

– only in mammals tubular, highly coiled

\
Eccrine Sweat Glands

– watery fluid that draws away heat, hairless regions like footpads, all over in some (man, horse)

Apocrine Sweat Glands

– larger, ducts more convoluted, open in hair follicle, at puberty in humans, armpits, ear canals, form a film on the skin, correlated with reproductive cycles

\
Scent Glands

– most mammals, vary in location and function, communication, mark territory, warning, defense, skinks, minks, weasels open in anus, very odoriferous, many give off strong scents during mating season to attract mates

Sebaceous Glands

– associated with hair follicles, cells accumulate fats, then die and expel oily sebum, does not turn rancid, keeps skin and hair pliable and glossy

Mammary Glands

– rudimentary on males, occur in all females, most evident only during pregnancy or lactation, humans fat accumulation at puberty, monotremes no nipples secrete milk into depression in mother’s belly

Teeth and Feeding Specialties

Unlike the uniform homodont teeth of the first synapsids, mammalian teeth have become heterodont, differentiating into different types for different functions: incisors for cutting, canines for piercing and holding on to food, premolars and molars for shearing, slicing, crushing, or grinding.

They also have diphyodont teeth, this means they have one set of primary teeth which are later replaced by a single permanent set, when the mammal is large enough to handle a full set of adult teeth.

In some of the mammals, some of these erect teeth (incisors) continue to grow, to replace material lost due to grazing (rodents).

Feeding specializations (carnivore, herbivore, piscivore, omnivore, insectivore, frugivore) lead to different combinations of teeth, so the teeth tell us a lot about the mammal that has or had them.

Mammalian Reproductive Patterns

Egg-Laying Monotremes

– oviparous, one breeding season per year, eggs fertilized in oviduct, albumin and thin leathery shell added, 12 days later lay eggs in nest they burrow, incubate another 12 days, suck milk after hatching from mother’s fur near mammary glands

Pouched Marsupials

– viviparous, not a “true” placenta, but do have a yolk sac placenta “choriovitteline”, embryo floats free a few days in shell membranes, hatch and embryo settles in a depression in uterine wall absorbing nutrients via yolk sac, gestation brief giving birth to young that are still embryos, birth followed by very long period of lactation and parental care

Placental Mammals

– viviparous, investment in a prolonged gestation for maximum development as opposed to marsupials who invest more in lactation, nourished through a chorioallantoic placenta “true” placenta, gestation longer than marsupials, much longer for large mammals (highest elephants at 22 months), gestation and body size loosely correlated as it depends upon how much maturity at birth there is. Humans slowest developing of all mammals

All apes, except for gibbons, belong to the family Hominidae and are hominids. Apes first appear in 23 million year old fossils, became terrestrial, and stood upright. The lineage that is more closely related to us than to other hominids are termed human, or hominins (genetically closer to living humans than to chimpanzees and bonobos), by the textbook. Describe those “first humans” and the groups that that lead up to modern Homo sapiens.

Genetic evidence suggests that humans diverged from chimpanzees about 10-7 MYA.

Sahelanthropus tchadensis 7 MYA

brain similar to chimp in size, brain size, small canines, massive brow ridges place in hominids earlier than previous

Ardipithecus ramidus 4.4 MYA

Australopithicus anamensis an intermediate 4.2 – 3.9 MYA.

Australopithicus afarensis “Lucy” short, bipedal, 3-7 – 3 MYA

brain at 380-470 cm3 chimp size The australopithecines that are more gracile with lighter builds are considered more closely related to early Homo species

Various extinct branches Paranthropus and Kenyanthropus

Homo habilis earliest Homo fully erect, used stone tools, larger brain 2.3 – 1.6 MYA

H. ergaster 2 – 1.4 MYA and H. erectus 1.8 MYA – 30 KYA larger brain, culture, controlled and used fire, buried their dead

H. floresiensis shorter

H. heidelbergensis 600-300 KYA

brain bigger 1100-1300 cm3

H. neanderthalensis 200 – 30 KYA,

brain 1400-1650 cm3 , proficient hunters and tool users

replaced by H. sapiens also 200 KYA,

brain 1100-1700 cm3 , reduced brow ridge, incorporate some “Neandertal” genes but outcompeted took about 10,000 years after overlapped in Europe to wipe out others, aesthetics, artistry, sophisticated language, better technology, superior culture.