exam four

vertebrates possess the folllowing characteristsics

Four-chambered heart, Endothermic and homeothermic, Hair. Mammary glands, Heterodont teeth, Three inner ear bones

Endothermy

the ability to generate metabolic heat independent of the outside environment

Homeothermy

refers to the ability to maintain a constant body temperature

mammary glands

produce milk to feed young offspring

hair is used for

insulation, protection, comouflage, communication

what group is thought to be the ancestors of mammals

cynodonts

monotremes (prototheria)

platypus and echidnas, egg-laying mammals, lack teeth, spurs on hind limbs

marsupials (metatheria)

opposums, kangaroos, koalas, wombats, etc., short gestation; fetal birth, development within pouch, yolk-sac placenta

placental mammals (eutheria)

wide range of adaptations for burrowing, flying, swimming, hunting, running, and climbing, long gestation; development within complex placenta, gestation inside of uterus

Monotreme Reproduction

leathery egg shells, platypuses lay 1-3 eggs, echidnas lay a single egg, retain eggs about two-thirds of developmental perod and then lay them in nests, babies hatch in fetal stage and complete development in nest

Monotremes: Platypus

leathery “duck bill”, paddle-like tail, webbed feet, auatice, constructs nest burrows in banks of rivers, males with venemous spur on hind limb, used in mle-male combat over mates

Monotremes: Echidnas

covered with coarse hair and keratinized spines, long slender snout with small mouth, eats earthworms, ants, termites, etc.

Chorioallantoic placenta

a large chorion tissue fused with a large allantois; interfaces maternal and embryonic tissues

evolutonary advantages of a Chorioallantoic placenta

increases size and development of young at birthm reduces “helpless period”, reduces dependence on natal sites such as dens and burrows

Proboscidea - Elephants

largest land mammals ever, three living species, most of this diverse group is extinct, ecosystem engineers

Sirenia

manatees, dugongs, sea cows, fully aquatic (both freshwater and marine, herbivorous, four living species

Xenathra

ateaters, sloths, and armadillos, unique limb and vetevral joints, bone structure, and teeth, extinct ground sloths

Lagomorpha

rabbits, hares, and pikas, 109 living species, four incisors in upper jaw

Rodentia

rodents, 40% of all mammal species, single pair of continuously growing incisors in each of the upper and lower jaw

Odd-toed ungulates

rhinoceroses, tapirs, horses, larger herbivores that hav reduced weight-bearing toes to 3 or 1

Even-toed ungulates

pigs, peccaries, hippopotamuses, antelopes, deer, giraffes, camels, llamas, alpacas, sheep, goats, cattle, Large herbivores that have reduced weight-bearing toes to 2 (hooves)

Even-toed ungulates - Cetaceans

whales and dolphins, evolved from common ancestor with hippos, fully aquatic, large streamlined bodies, includes the largest animal ever known to have existed (blue whale)

Carnivora

dogs, cats, bears, seals, otters, skunks, etc., diverse group specialized for eating other animals, carnasial teeth

Chiroptera

Bats, forelimbs adapted for sustained flight, highly developed echolocation system used for hunting and navigation

Primate Characteristics

large brains, increased reliance on sight, color vision, decreased reliance on smell, use of tools, highly developed social behaviors

prosimians

lemurs, lorises, bush babies, pottos, mostly nocturnal, large olfactory centers in the brain than anthropoids, smaller size and smaller brain than anthropoids

monkeys

mostly diurnal, rely on vision more than smell, new world monkeys: broad noses, prehnsile tails, old world monkeys: narrow downward-pointed noses, no prehensile tails

apes

tailess, large-bodied, high brain-body size ratio

Australopithecus afarensis

longest existing and best known fossil hominids, bipedal footprint trails, small canine teeth, long strong arms, apelike face

Paranthropus

cousins, short stout bodies, skulls adapted for chewing, large chewing muscles, large molars

Homo habilis

first early homo species to use stone tools, walk on the ground on two legs, had arched feet, elongate arms

Homo erectus

“upright man”, oldest known early humans to have modern human-like body proportions, first species to widely expand its range out of africa, use of tools, hearths for cooking, evidence of care for old/weak

Archaic Humans

recent human evolution very complex, multiple closely related species that inbred repeatedly

Modern Humans

Genetic evidence indicates that modern
humans shared a single common ancestor in
east Africa

biosphere

all of the parts of Earth inhabited by life

biomes

large areas of habitat with similar climate, flora, and fauna

Temperate Forests

Deciduous trees are those that lose their leaves in Fall and Winter, Cool, moist winters, Warm, moist summers, Dominant habitat of eastern USA, Pennsylvania = “Penn’s Forest Land”

Boreal Forest/Taiga

World’s largest terrestrial biome, Mostly evergreen forest, dominated by spruce, fir, and pines, 29% of all forest cover on earth, Short, cool, wet summers, Long, cold, wet winters, short growing season

Tropical Rainforests

Evergreen wet forests between the Tropics of Cancer and Capricorn, highest biodiversity of any terrestrial biome, 21% of all forest cover on earth, Warm all year, Wet all year, Low soil fertility

Grasslands

Grasslands and prairies in temperate zones, Warm, wet summers, Cold, dry winters

Savannas

Tropical grasslands with sparse trees, Hot, wet summers, Warm, dry winters

Deserts

Cool to mild winters, Warm to hot summers, Dry all year, Often extreme day-night temperature variation

Tundra

Arctic grasslands with permafrost layer, Permafrost – Permanently

frozen soils, Cold all year, Short, wet summers, Long, dry winters

Aquatic Biomes

Oceans make up 71% of the entire surface area of the Earth, Aquatic Biomes are separated into marine (salt-water, ocean-associated) and freshwater (associated with lakes and streams)

Abiotic Factors Influencing Aquatic Biomes

energy sources, temperature, type and changes in water, nutrients and inorganic materials

Estuaries

the areas where rivers meet the ocean, Mangroves are salt-tolerant trees that line estuaries and tidal areas in the tropics, Nutrient-rich and highly productive, Physiologically challenging for inhabitants, Critical habitat for coastal flood protection (ecosystem service value)

Coral Reefs

Ridges in photic zone created by Cnidarians (corals) and Molluscs, High biodiversity- “Rainforests of the ocean”, Provide critical habitat for thousands of species, Nursery areas for larger ocean-going species

Pelagic Realm

Largest of earth’s biomes, due to volume, The entire ocean other than the coast and the ocean floor (the benthic zone), The average depth of the ocean is ~2.5 miles

Freshwater Biomes

Includes lentic (standing water) and lotic (flowing water) ecosystems, Lakes, ponds, rivers, streams, wetlands

Freshwater Lotic Systems

Flowing freshwater systems – streams, creeks, rivers, Uni-directional flow, Constant physical change, Variety of microhabitats (pools, riffles, large rocks, gravel beds, etc)

Freshwater Lentic Systems

Standing water systems (ponds, lakes, wetlands), Can be permanent or seasonal/temporary (vernal pools and ephemeral ponds)

What are the six characteristics that distinguish mammals from other vertebrates. Provide a description of each characteristic and include details of each.

• Four-chambered heart: allowing for high metabolic rates by ensuring oxygenated blood is effectively delivered to the body

• Endothermic and homeothermic: create and store their own heat

• Hair: used for insulation, protection, camouflage, and communication

• Mammary glands: produce milk to feed young offspring

• Heterodont teeth: speciealized teeth with varying shapes for different functions

• Three inner ear bones: Malleus, incus, stapes, Derived from two small jaw bones

Compare and contrast reproduction in the three major groups of mammals (monotremes, marsupials, and eutherians). Include details of the young at birth, development, and type of placenta in each group.

• Monotremes: egg-laying mammals, leathery egg shells, yolk-sac placenta, hatch in fetal state and complete development in nest

• Marsupials: short gestation; fetal birth, development within pouch, yolk-sac placenta but no egg shell

• Placental mammals: long gestation; development inside of uterus within complex placenta that connects fetus to mother

Which group of mammals contains some of the largest land animals ever to live?

Proboscidea

What group of animals includes the largest animals to have ever lived (and is alive today)?

Even-toed ungulates - cetaceans

_____________ is the group that includes the only species of venomous mammal.

Monotremes

Which group of mammals has a single pair of continuously growing incisors in each of the upper and lower jaws, which it has to constantly chew and gnaw with to keep from overgrowing?

Rodentia

Which group of mammals has four incisors in their upper jaw, with the second pair growing behind the first and referred to as "peg teeth"?

Lagomorpha

What are six shared characteristics of primates that differentiate them from other mammals?

rotating shoulder joint, big toe and thumbs widely separated from other toes and fingers, stereoscopic vision, brains larger than most other mammals, claws modified into flattened nails, typically only one offspring per pregnancy

What are Prosimians? What are three ways they differ from Anthropoid primates?

they are Lemurs, lorises, bush babies, pottos

1) Mostly nocturnal

2) larger olfactory centers in the brain than anthropoids

3) smaller size and smaller brain than anthropoids

List the four genera of living great apes.

Genus Pan, Genus Gorilla, Genus Pongo, Genus Homo

In your own concise words, describe the evolutionary history of our species (Homo sapiens) since our lineage diverged from the last common ancestor with the Pan lineage ~6 million years ago. Include mention of Australopithecus afarensis, Paranthropus, Homo habilis, Homo erectus, and archaic humans.

6 million years ago, the human lineage split from the ancestors of chimpanzees. Early hominins like Australopithecus afarensis were bipedal with small brains; later, Paranthropus evolved specialized chewing traits and went extinct. Homo habilis showed early tool use, followed by Homo erectus, which had human-like body proportions and spread out of Africa. Archaic humans evolved from these populations, interbred repeatedly, leading to modern Homo sapiens.

What two abiotic factors shape the distribution and extent of terrestrial biomes on Earth?

annual mean temperature and annual mean precipitation

Label and briefly define each of the six oceanic biomes in the above diagram.

• A: Pelagic Realm - the open ocean

• B: Neritic Zone – From intertidal zone to edge of continental shelf, where waters are <200 m deep

• C: Intertidal Zone – zone between low and high tide

• D: Photic zone – part of pelagic zone where light penetrates (to about 200 m)

• E: Aphotic zone – part of pelagic zone where no light penetrates (below about 200 m)

• F: Abyssal zone – deepest ocean (>4000 m deep), extreme pressure and cold