Unit 3 Test
Blastocoel
Hollow cavity of blastula
Placental Mammals
(The rest of Animals) - Complete their embryonic development within a uterus, joined to the mother by the placenta
Homeostasis: Regulator
(Warm-Blooded) An animal that uses internal control mechanisms to regulate internal changes due to the environment: Homeostasis = maintaining a constant internal environment (temperature, ion concentration, blood sugar levels, etc.)
Hominid Evolution
(fossil human-like apes more closely related us than chimps) Primary features that seperate humans from other African Apes: - We walk upright on two legs = BIPEDAL - Increased relative skull/brain size, particularly frontal lobe (Bipedalism evolved BEFORE increased relative brain size) Homo Sapiens indistinguishable from modern human skeletons first appear in the fossil record ~200,000 years ago
Vitamins
Vitamins are organic molecules required in the diet in small amounts 13 essential vitamins grouped into fat-soluble and water-soluble
Muscle: Skeletal Muscle Tissue
Voluntary muscle pulls on bones and causes body movements.
Endothermy
Warmed mostly by heat generated by metabolism Examples: Birds and Mammals (A few non-avian reptiles, fish, and many insects)
Neurotransmitter - Acetylcholine
released by nerves and causes skeletal muscles to contract, activates pain responses and regulates endocrine and REM sleep functions
Anthropoids
new world monkeys, old world monkeys, gibbons, orangutans, gorillas, chimpanzees and bonobos, humans
Erythrocytes (Red blood cells)
no nuclei, transport O2 and CO2
Fat-Soluble Vitamins
Vitamins A, D, E, K
Water-Soluble Vitamins
Vitamins B and C
Hierarchial Organization of Body Plans
Cells with common structure and function make up TISSUES Different tissues make up ORGANS which together make up ORGAN SYSTEMS Tissues are classified into four main categories 1) Epithelial 2) Connective 3) Muscle 4) Nervous
Nicotine
Directly stimulates the release of dopamine
Placental Animals: Xenarthra
(Armadillo, Sloths, Ant-eaters, NOT shrews) - Second farthest branching from all of the Placental mammals
Placental Mammals: Euarchontoglires
(Carnivores, Hooved mammals, bats, moles, shrews, whales) Most closely related group to Laurasiatheria
Homeostasis: Conformer
(Cold-blooded) An animal that allows internal conditions to conform to external environmental changes. Homeostasis = maintaining a constant internal environment (temperature, ion concentration, blood sugar levels, blood glucose, blood pH, etc.)
Placental Mammals: Afrotheria
(Elephants, Manatees, Shrews, Aardvarks, etc.) - Farthest branching from all of the Placental mammals
Radially Symmetric Animals...
(Jellyfish, etc.) - Diblastic animals have endoderm and ectoderm - Have two tissue layers (endoderm=gut lining and ectoderm= outer layer)
Marsupials
(Opossums, Wombat, Kangaroos, Koala, Marsupial Moles, Sugar Gliders, Tasmanian Devil, Tasmanian Wolf, etc.) - Embryo born early, finishes development within a maternal pouch called a MARSUPIUM - Extremely diverse in Australia - Marsupials fill all the mammal ecological roles that are filled by Placental Mammals on other continents. This has led to lots of convergent evolution between Placental Mammals and Marsupials
Monotremes
(Platypus, Echidna) - Retain the primitive egg-laying condition: echidnas and platypus-only in Australia. Also, no nipples!
Placental Mammals: Laurasiatheria
(Rodents, rabbits, shrews, primates, model mammal, humans) Primates (including humans) are related to rabbits and rodents
Nitrogenous Waste Forms - Mammals and Amphibians
+ Some Aquatic Animals, ex: sharks Urea is produced in the liver of some animals from ammonia (urea is much less toxic); urea is then carried to the kidneys where it is concentrated and excreted with minimal loss of water.
Bilateral Animals Have:
- A Dorsal (top) side and a Ventral (bottom) side - A right and left side that are approximately symmetrical - Anterior (head) and posterior tail (ends) - Having a distinct mouth often leads to CEPHALIZATION, development of a head
Amniotes
- Amniotes are tetrapods that have a terrestrially adapted egg - the amniotic egg - which contains specialized membranes that protect the embryo from drying out but allow for gas exchange - Two extant clades: Reptiles and Mammals - Produce projections of Keratin (protein in scales, feathers, hair, fingernails, etc.) from skin follicles and breath via rib cage ventilation (use muscles to expand and contract rib cage area for more efficient air movement in and out of lungs)
Intervertebrates
- Animals that lack a backbone - Defined by an ancestral characteristic, not a synapomorphy, so they would be a PARAPHYLETIC group, i.e. some invertebrates are much more closely related to vertebrates than they are to other vertebrates
Lab mice and Lab rats...
- Are popular as EXPERIMENTAL animals because they are the closest living relatives of humans that are small, reproduce quickly (10 week generation time), and most people think of them as pests they don't mind killing them as much.
Lobe-Fins: Lungfish
- Are the closest relatives to land vertebrates (Tetrapods) and depend entirely on lungs, not gills for breathing! They also have the largest known genomes! (i.e. more DNA per nucleus than any other organism-including humans)
Lobe-Fins: Coelacanths
- Are well-represented in the fossil record but were a shocking discovery when living representatives were found at the bottom of the ocean. Swim bladders are filled with oil to keep them from floating far from the ocean floor.
Eutherian (Placental Mammal) Lineages
- Bats, carnivores, hooved mammals, shrews (smallest mammal) and whales (largest animals) all found in one clade - Life habits known as 'Moles and Shrews' are in multiple placental lineages as well as marsupials - Primates (include humans) are related to rabbits, rodents; lab rats and lab mice are popular as EXPERIMENTAL animals because they are the closest living relatives of humans that are small, reproduce quickly (10 week generation time), and most people think of them as pests they don't mind killing them as much.
Phylum Placozoa - Placozoans (Flat, Pancake-like thing of cells)
- Behave like a multicellular amoeba and move with cilia. Probably branched off after Porifera and Ctenophora and are a result of simplification/reduction of an ancestor with tissues.
Why can bird lungs function at much higher elevations than human lungs?
- Birds have as many as 9 air sacs that function as small "bellows" that keep air flowing through the lungs continuously in one direction - no inefficient mixing of gases at the inhale/exhale boundary like mammals - Increased efficiency allows them to survive better at lower oxygen pressures (higher altitudes) than mammals (e.g. birds can fly over the highest peaks of the Himalayas, while people need oxygen tanks to survive the climb to the top of Mount Everest). - No Inefficient Mixing of gases!
Reptiles: Turtles
- Boxlike shell: Upper and lower shields made of fused vertebrae and ribs, covered with modified scales - Some live in deserts, others have returned to the sea (still must lay eggs on land) - No teeth
Phylum Cnidaria - CORALS
- Corals have endosymbiotic, photosynthetic chromalveolates from the SAR clade (zooxanthellae) living between their endoderm and ectoderm tissue layers; provide and environment with more inorganic nutrients and carbon dioxide for the endosymbiont in exchange for sugar (similar to lichens and mycorrhizal fungi)
An adequate diet must satisfy three nutritional needs:
- Fuel for cellular work - Organic raw materials for biosynthesis (carbon skeletons) - Essential Nutrients, substances the animal cannot make for itself
Lobe-Fins
- Have muscular pectoral and pelvic fins surrounding rod-shaped bones - Includes Coelacanths, Lungfishes, and Tetrapods
Ray-Finned Fish
- Includes nearly all the familiar aquatic fish, ~ half of all vertebrates - Fins are supported mainly by long, flexible rays, not bone or muscle - Possess SWIM BLADDERS (Gas Bladders) homologous to lungs-mostly control buoyancy, but many fish can absorb some oxygen through them - Most diverse group of vertebrates; lots of saltwater species, but much of the diversity lies in geographically-separated freshwater drainage (lots of allopatric speciation). Southeast USA is particularly diverse, with the Etowah in Northwest Georgia containing many more species than the two largest rivers in the western USA, the Columbia and Colorado rivers, combined - Zebrafish (Danio rerio) is a model organism often used in research; small genome (one the first vertebrate genomes to be sequenced) and a very short generation time (3 months from egg to adults laying eggs) make it useful for experiments
Characteristics of Animals
- Ingest Food and Digest it internally with enzymes - Multi-cellular with no cell walls - held together by proteins (collagen, cadherins, etc.) - Formation of a blastula/gastrula (hollow ball of cells that indents to form a cavity)
Lepidosaurs: Snakes
- Legless lepidosaurs that evolved from a lizard-like ancestor (lizards are probably PARAPHYLETIC unless you include snakes); multiple evolutionary origins of highly venomous species
Bony "Fish"
- Most living vertebrates (including humans and other land vertebrates) belong to a clade of jawed vertebrates called Osterichthyes (means bony fish) - Some Bony "Fish" are not fish as we normally think of them! (land vertebrates!) - There are two living groups of Bony Vertebrates: Ray-finned Fish and Lobe-fins
Lepidosaurs: Lizards
- Most numerous and diverse reptiles, apart from birds; a couple venomous species; some have independently lost their legs - convergent evolution with snakes; 2 venomous species (also convergence with multiple snake lineages)
Primates
- Most of the basal primates (Bush Babies, Lorises, Tarsiers) are nocturnal, tree-dwelling, insect-eaters; this indicates that the ancestor of all primates shared these characteristics and likely evolved the better binocular vision and gripping hands/thumbs shared by all modern primates due to selection for this lifestyle. - Primates are originally an Old World group (Africa, southern Europe, and Asia), but one lineage did colonize the New World from Africa before humans (New World Monkeys) - Old World Monkeys are more closely related to apes (including humans) than they are to the monkeys of Central and South America
Lepidosaurs: Tuataras
- Old, unique lineage now isolated to a few Pacific Islands
Insects: Good Stuff
- Pollinators: honey, beeswax, silk, forensics, invasive species control, research (Fruit Flies used for genetics/chromosome research), aesthetics (butterflies, fireflies), food for many animals
Deuterostomes - Phylum Enchinodermata
- Slow-moving marine animals: include sea stars, brittle stars, sea urchins, sea cucumbers - Molecular and embryological data support a shared common ancestor for Echinoderms and Chordates - Sea Urchin sperm/eggs in studies of fertilization and early embryonic development - Radial-like anatomy evolved secondarily from the bilateral symmetry of ancestors (not actually radially symmetric) - Spiny skin covers a skeleton of hard calcium carbonate plates
Vertebrates
- Subphylum of Chordata - ~64,000 extant species - Name derived from vertebrae, the series of dorsal bony segments - Possess a Cranium (skull) and "Backbone" (made of cartilage, not bone, in many)
Homo neanderthalensis
- Subspecies of Homo sapiens - Interbred with homo sapiens for 20,000 years ago - our genome is 1-2% of them
Phylum Ctenophora - Comb Jellies
- Superficially similar to true 'jellyfish' (Phylum Cnidaria) and used to be grouped with them, but differ in locomotion by rows of cilia and lack of tinging cells. - Similar to a big gastrula - Recent sequence of a Ctenophore genome indicates they may actually be the basal branch of animals (i.e. outside of sponges), but exact placement relative to Profiera (sponges) and Cnidaria (jellyfish) is still debated
Bilaterally Symmetric Animals...
- Triploblastic (generally bilaterally symmetric) form a third mesoderm layer in between endoderm and ectoderm - Have all 3 tissue layers (endoderm, medoderm, and ectoderm)
Insects: Bad Stuff
- Vectors for Disease: Malaria, Yellow Fever, Dengue, West Nile (mosquitoes), Chagas (kissing bugs), African Sleeping Sickness (Tsetse Fly), etc. - Biting/stinging; mosquitoes, deer flies, black flies (gnats, noseeums), stinging wasps, fire ants, bedbugs, etc. -Economic/agricultural damage
Tetrapods: Amphibians
- ~4800 species of frogs, salamanders, caecilians (legless amphibians that look like snakes or legless lizards: convergent evolution) - Remain closely tied to water, especially for reproduction - aquatic eggs unprotected from desiccation, aquatic juvenile stages with gills and (usually) terrestrial adults - Delayed development of arms/legs in tadpoles is a derived characteristic of amphibians, not ancestral to tetrapods - Most breathe through skin and legs at maturity (using throats muscles to pull and push air in and out of lungs), although many salamanders breathe entirely through their skin
"Fish"...
...are not MONOPHYLETIC unless land vertebrates are considered land fish; i.e. Fish refers to almost any cold-blooded aquatic vertebrate lineage, but some lineages of aquatic fish are more closely related to land vertebrates than they are to other aquatic fish lineages
Resting Potential
1. Sodium/Potassium pump ships Sodium ions out of the axon and Potassium ions into the axon (exchange of one positive ion for another positive ion). 2. Some Potassium channels are open for Potassium ions to diffuse back out of the axon; fewer Sodium channels are open to allow Sodium to diffuse back into the axon, resulting in more positive ions outside the axon than inside; inside of the axon is now negatively charged. 3. An equilibrium known as the RESTING POTENTIAL is reached between charge and concentration (lower Potassium concentration outside the axon promotes diffusion of Potassium to the outside, but negative charge inside the axon attracts Potassium and limits how much leaves). The net result is that the inside of the axon has a slight negative charge and the outside of the axon has a slight positive charge at resting potential.
Action Potential
1. When a nerve is stimulated, more Sodium channels are allowed to open. 2. If enough Sodium channels are activated to open, Sodium ions rush into the cell because of the negative charge and low Sodium concentration there. The rush of Sodium ions into the cell cause a sudden reverse in charge, so that during the ACTION POTENTIAL phase a portion of the axon becomes briefly positively charged on the inside of the membrane and negatively charged on the outside of the membrane (reverse of resting potential). This stimulates more sodium channels to open further down the axon. 3. The action potential is quickly restored to the resting potential by closing sodium channels, opening potassium channels, and using the sodium/potassium pump to restore the resting potential concentrations of each ion inside and outside the cell. The action potential travels down the length of the axon like electricity is conducted down a metal wire. Action potentials last only a few thousandths of a second, so a neuron can 'fire' hundreds of times per second. Neurons either fire or they don't (no such thing as weakly or strongly firing, only firing more often or less often).
Amphibians and Non-Bird Reptiles...
3 chambers: 2 atriums and 1 ventricle
Single Circulation
A circulatory system consisting of a single pump and circuit, in which blood passes from the sites of gas exchange to the rest of the body before returning to the heart. - Fish, 2-Chambered Hearts, where gills then to body then to heart
Double Circulation
A circulatory system consisting of separate pulmonary and systemic circuits, in which blood passes through the heart after completing each circuit. Examples: - Amphibians and Non-Bird reptiles: 2 atriums and 1 ventricle with separation between circulation for oxygenation and for pumping oxygenated blood to body. - Mammals (&Birds): 2 atriums and 2 ventricles with complete separation into 4 chambers.
Binary Fission
A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size Examples: Bacteria and Hydra
Budding
A form of asexual reproduction of yeast in which a new cell grows out of the body of a parent.
Fragmentation
A means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals. Examples: Starfish, Cnidarians (Jellies, Corals, Hydra, and Anemones), Sponges, Segmented Worms, and Sea Squirts
Immune System: Acquired Immunity
Acquired Immunity: A specific response to pathogen - B-Cell Lymphocytes are made in the bone marrow and produce antibodies - T-Cell Lymphocytes are made in the thymus gland and identify foreigners to target. - MHC proteins then bind to antigens and present them to T-cells on the cell surface - Cytotoxic T-cells directly kill the cell - Helper T-cells bring antigens to B-cells for antibody synthesis (Helper T-cells are targeted by HIV and lead to rare infections and cancers in people with AIDS)
Deuterostomes - Phylum Chordata
All chordates share a set of 4 derived characters: - Notochord - Dorsal hollow nerve cord - Muscular post-anal tail - Pharyngeal gill slits - Some of these traits are only apparent during embryonic development in many chordates (human lose gill slits early in embryonic development, notochord becomes cartilage disks between vertebrae, muscular tail stops growing early on as the rest of the embryo develops)
Essential Amino Acids
Animals require 20 amino acids (can synthesize about half as long as diet contains some nitrogen: adult humans need 8 from our diet) Essential Amino Acids: Methionine Valine Threonine Phenylalaline Leucine Isoleucine Tryptophan Lysine - The essential amino acids must be obtained from food in preassembled form - A diet insufficient in essential amino acids causes a form of malnutrition called PROTEIN DEFICIENCY - Most plant protein are incomplete in amino acid makeup
Lophotrochozoa: Phylum Annelida
Annelida = Segmented Worms - Segmented Bodies - convergent evolution with arthropods - Includes Earthworms, Leeches, many intertidal saltwater species and tubeworms - Tubeworms have chemoautotrophic bacteria living in their tissues; help form the base of the food chain in some places at the bottom of the ocean even where there is no light
closed circulatory system
Annelids Squid Octopi Vertebrates
Apes - Generalization
Apes = Gibbons, Orangutans, Gorillas, Chimpanzees & Bonobos, and Humans) have vestigial tail that stops growing early in development. * Gibbons are fast tree-swingers and live in Asia, Orangutans also live in trees in Asia but are larger, slower, and more closely related to African Apes (Orangutans + African Apes = Great Apes) Gorillas + Chimpanzees & Bonobos + Humans = African Apes Chimpanzees & Bonobos are derived from a common ancestral population with humans ~7+ million years ago and are our closest living nonhuman relatives
Apes
Apes = Gibbons, Orangutans, Gorillas, Chimpanzees & Bonobos, and Humans) have vestigial tail that stops growing early in development.
Schwann Cells
Are flat cells that produce myelin (myelin = a lipid-rich medium that doesn't conduct electricity) that wrap around the axon to form many layers. Insulate and prevent leakage of electrical current between sections of the axon with Sodium/Potassium channels. The current moves very quickly between these nodes thanks to the insulation provided by Schwann Cells, which greatly improves neuron efficiency.
Ecdysozoa: Phylum Arthropoda
Arthropoda = Jointed animals with exoskeletons Arthropods are segmented invertebrates with jointed appendages: Include: CRUSTACEANS, CHELICERATES, MYRIAPODS, HEXAPODS, also TRILOBITES (extinct) - Arthropoda includes two thirds of all described species of animals; Crustaceans and, especially, Insects are huge subgroups - Found in nearly all Earth habitats (Crustaceans especially in saltwater and freshwater habitats, Insects in terrestrial and freshwater habitats) - Body covered by an external skeleton (exoskeleton) composed of the polysaccharide chitin (same as fungal cell walls!), infused with calcium
Crustaceans
Arthropods - Crabs, lobsters, shrimp, barnacle
Chelicerates
Arthropods - Horseshoe crab, scorpions, spiders, ticks, mites, etc.
Myriapods
Arthropods - Millipedes and Centipedes
Insects (Hexapods)
Arthropods (subgroup of Arthropoda) - Most order of insects go through successive nymph stages that more or less look like smaller versions of the adult (sometimes without wings in winged species) - However, the four most diverse order of insects: - Beetles - Moths and Butterflies - Flies - Ants and Wasps ...go through a distinct complete metamorphosis from juvenile to adult stages. - EARLY stages are for feeding (caterpillars, grubs, maggots), PUPAL stage is a protective outer skin while the insect undergoes drastic morphological changes, ADULT stage is primarily for reproduction. - Any feeding by adult stages, if they feed at all, is strictly for maintaining energy for reproductive activities
Parthenogenesis
Asexual reproduction in which females produce offspring from unfertilized eggs. Examples: WHIPTAIL LIZARDS - Bees, Aphids, Fish, Frogs, Lizards like Komodo Dragons, and Hammerhead sharks
Acoela
Basal Lineage of Bilateria: bilaterally symmetric flattened 'worms'. - Are reminiscent of what the ancestral bilateral animals may have looked like.
Digestion - Liver
Bile Salts produced in the liver and stored in the gall bladder act as EMULSIFIERS to digest lipids.
Cocaine and Methamphetamine
Block the removal of dopamine from synapses
Blood Filtration
Blood is filtered into the tubes of the NEPHRON, where they traverse the osmolarity gradient of the cortex and medulla. Secretion and reabsorption substantially alter the volume and composition of filtrate - more water avilable allows more urea to be removed: a lot of energy is spent to actively transport nutrients in and out of the nephron tubule at various points.
Bilaterial symmetry
Body parts arranged in a similar way on both side of the image of the other half. Evolved after sponges and Cnidarians (Jelly fish) had already diverged from other animals; bilaterally symmetric animals all have 3 tissue layers with a mesoderm layer filling in space between the endoderm and ectoderm.
Dendrites
Branched extensions receive signals from other neurons.
Platelets
Cell fragments involved in blood clotting during wound healing.
Blood Compositon
Cellular Elements = 45% of volume, Plasma is 55% of volume Suspended in liquid matrix called PLASMA made of: - Water - Plasma proteins - Blood electrolytes (dissolved ions) - Transported substances (nutrients, gases, wastes, hormones) 45% of Volume is made of three classes of cellular elements: 1) Erthrocytes (Red blood cells) 2) Leukocytes (White blood cells) 3) Platelets
Hormone
Chemical signal secreted into the circulatory system that communicates regulator messages - may reach all parts of the body, but only target cells with proper receptors for the hormone can respond - Frequently occur in antagonistic pairs (e.g.g. Insulin and Glucagon to regulate blood sugar, PTH and Calcitonin to regulate blood Calcium)
Closed Circulatory Systems
Closed systems: annelids, squids and octopuses (cephalopod molluscs), and ALL vertebrates - Circulatory fluid (blood) is confined to vessels, distinct from the interstitial fluid - More efficient at transporting fluids to cells - Can work at higher pressure (and speed) - Faster diffusion
Epithelial tissue
Closely packed sheets of cells that cover the outside of body and line organs and cavities within Includes: Skin and Organ Linings
Protostomes - Ecdysozoa
Ecdysis: Molting skin/exoskeleton Include the Phylums: - Nematoda - Arthropoda
Opiates (including heroin)
Decrease activity of neurons that normally would be inhibiting dopamine release.
Nitrogenous Waste Forms - Aquatic Animals
Diffuse ammonia into the water to prevent toxic ammonia from building up in their bodies.
Archosaurs: Dinosaurs
Dinosaur diversity is also lower than in the past: today only birds remain, but they are still the most diverse tetrapod lineage with ~10,000 species, about twice as many extant species as mammals - Warm-blooded,- many features of their reptilian anatomy underwent modification during adaptation to flight: hollow bones, no teeth, no bladder - Descended from a group of small, feathered carnivorous theropod dinosaurs ~ 170 MYA (velociraptors had feather! Their feathers were no insulation, not flight) - Some are primarily oceanic, coming to land only to lay eggs similarly to sea turtles (e.g. penguins, albatrosses) - Diversified into sizes from 20+ ft (extinct moas) & 2000 lbs (extinct elephant birds, terror birds), to as small as a hummingbird (largest extant birds are ostriches at ~8ft, ~200+ lbs) - Fastest animal on earth is the Peregrine Falcon (over 200 MPH in dives on prey) - Falcons, hawks, shrikes, and owls are unrelated, independently evolved lineages that have reverted back to being carnivores.
Axons
Elongate processes, the ends of which divide into multiple synaptic terminals to communicate with other cells at synapses (junction of neuron with another neuron or other cell)
Hormones - Example
Epinephrine/ Adrenaline has different functions between liver and smooth muscle cells surrounding blood vessels leading to skeletal muscles even though it uses the same receptor, and it has opposite function in smooth muscle cells surrounding blood vessels in the intestines with a different receptor
Neurotransmitter - Nitric Oxide
Erections Function most manipulated by humans is inducing vasodilation during sexual arousal. Erectile disfunction drugs help maintain levels of Nitric Oxide in the necessary synapses.
Homo sapiens
Evolved in Africa and migrated into Asia/Europe ~70,000 years ago, became second primate lineage (after New World Monkeys) to colonize North and South America ~15,000 years ago via the Bering Land Bridge (Asia to Alaska)
Internal Exchange Surfaces
Exchange surfaces in complex, multicellular organisms connect to the environment via body surface openings Highly folded or branched for increased SURFACE AREA Other cells of body are connected to exchange surfaces by circulatory fluids and interstitial fluids
Nitrogenous Waste Forms - Reptiles, Birds, insects, land mollusks
Form uric acid which is largely insoluble in water, can be secreted as a paste with very little water loss.
Mammalian Respiratory Systems
From NOSTRILS, air passes through the PHARYNX into the TRACHEA, BRONCHI, BRONCHIOLES, and ALVEOLI, where gas exchange occurs. Humans have about 600+ miles of capillaries and 100 square meters of surface area exposed for gas exchange in alveoli
Gills in Aquatic Animals
Gills = outfoldings of tissue specialized for gas exchange. - Effectiveness of gas exchange is increased by VENTILATION (is the movement of water across gills) and COUNTER-CURRENT FLOW of blood and water; blood passes the most oxygenated water last before continuing to the body to maximize efficiency and bring the blood as close as possible to the oxygenation level of the water
Mammals and Birdas...
Have complete separation into 4 chambers: 2 atriums and 2 ventricles.
Nervous System
High-speed electrical signals along specialized cells (neurons)
Blastula
Hollow ball of cells in early embryonic development
Endocrine System
Hormones (secreted by endocrine glands) coordinate slower but longer-acting responses to stimuli
Know how hormones work with regards to receptors and cell types.
Hormones (secreted from endocrine system) - Slower but longer acting responses - chemical signal, to the circulatory system, that communicates regulatory messages - Target cells respond to hormones Target cell Responses differ when... - different receptors are on the same type of cell - same receptors are on a different type of cell
Leukocytes (White Blood Cells)
Immune system and immune response to viruses.
Neurotransmitter - Serotonin
Important in calming and feelings of well-being - SSRIs (Selective Seratonin Reuptake Inhibitors) slow the rate at which serotonin is reabsorbed by the signaling neuron, keeping serotonin levels in the synapses at higher levels. SSRIs are the most commonly prescribed type of drug it in the world
Neurotransmitter - Dopamine
Important in reward response - involved in pleasure and addiction
Protostomes - Lophotrochozoa
Include the Phylums: - Platyhelminthes - Mollusca - Annelida
Amniotes: Reptiles
Includes three extant clades: turtle, lepidosaurs (tuataras, lizards, snakes) and archosaurs (crocodilians and dinosaurs - including birds!) - Possess scales (or feathers!) that create a waterproof barrier - Lay shelled eggs on land
Simple Chordates
Invertebrates - Lancelets (first branched lineage of chordates) retain the characteristics of the ancestral chordate body plan as adults - Sea Squirts (Tunicates) start out as a 'tadpole' larva with all 4 chordate characteristics, develop into permanently anchored filter feeders like sponges: notochord, tail, and dorsal nerve chord lost at maturity
Muscle: Cardiac Muscle Tissue
Involuntary muscle tissue found only in the heart.
Muscle: Smooth Muscle Tissue
Involuntary muscle tissue that is found in the intestines where it pushes food along the digestive tract. Also found in arteries and veins.
First branch of vertebrates
Jaw Fish: lineage with no jaws, no paired fins
Lampreys
Jawless Fish - Cartilaginous segments surrounding notochord (cartilage for structural support) and arching partly over the nerve cord (simple vertebrae!) - Lampreys and hagfish both also have much simpler eyes than other vertebrates, with hagfish eyes reduced to almost nothing
Hagfish
Jawless Fish - Have a head (cranium) - No vertebrae (probably a SECONDARY LOSS to help them knot up to escape predators) - Slimy!
Vertebrate Kidneys
Kidneys, the excretory organs of vertebrates, function in water balance, salt regulation, and excretion Kidneys produce urine by refining a filtrate derived from body fluids NEPHRONS and associated blood vessels are the function unit of the mammalian paired kidneys Each kidney supplied with blood by a RENAL ARTERY and drained by a RENAL VEIN Two distinct regions - Outer RENAL CORTEX, inner RENAL MEDULLA
Cartilaginous Fish (Sharks, Rays, etc.)
Lack fully hardened bones, but share the following characteristics with bony vertebrates: •Mineralized internal skeleton of calcium-infused cartilage •Jaws •Two sets of paired appendages (Pectoral fins and pelvic fins in locations homologous to our arms and legs)
Osmoregulation in Land Animals
Land animals manage their water budgets by: - Drinking and eating moist foods - Using water generated by aerobic respiration (metabolic water)
Digestion - Large Intestine (Colon)
Large Intestine mostly reabsorbs water, but also holds bacteria that produce Vitamin K and biotin (Lactose intolerance caused by further digestion).
Mammal - Shrews
Life habits known as 'Moles and Shrews' are in multiple placental lineages as well as marsupials Things called "shrews" (=small, mouse-like insectivorous mammals with a pointy snout) exist in all of the lineages except Monotremes and Xenarthra Ancestral mammal was probably shrew-like based on the fossil record. 'Shrews' are mousey, with a long pointy snout for eating insects. All other mammal body forms, from whales to humans, have evolved from a shrew-like body plan.
Reptiles: Lepidosaurs
Lizards, Snakes, Tuataras
Muscle Tissues
Long cells called muscle fibers are capable of contracting in response to nerve signals Three Types in Vertebrates: 1) Skeletal Muscle Tissue 2) Cardiac Muscle Tissue 3) Smooth Muscle Tissue
Thermoregulation
Maintenance of an internal temperature within a tolerable range - can involve adaptations of anatomy, physiology, behavior. Endothermy and Ectothermy In general, ECTOTHERMS tolerate greater variation in internal temperature than endotherms. ENDOTHERMY is more energetically expensive than ECTOTHERMY, and the larger an endothermic animal is, the more efficient it is at maintaining temperature.
Deuterostomes
Means "Second mouth"; initial indentation during gastrulation becomes the ANUS, MOUTH forms after the gastrointestinal tract has grown through to the other side.
Protostomes
Means "first mouth"; initial indentation during gastrulation becomes the MOUTH, ANUS forms SECOND, after the gastrointestinal tract has grown through to the opposite end of the embryo 2 major groups of Protostomes: - Lophotrochozoa - Ecdysozoa
Minerals
Minerals are necessary inorganic nutrients usually required in small amounts Humans need greatest amounts of Ca, P, S, K, Cl, Na, and Mg *More than 200 mg a day for the essential minerals
Lophotrochozoa: Phylum Mollusca
Mollusca = Snails and Slugs, Oysters and Clams, Octopi and Squid - Largest marine phylum by species - although inhabit fresh water, some are terrestrial (some snails and slugs) - All are anatomically separated into HEAD, FOOT, and MANTLE Bivalves, Gastropods, and Cephalopods - Soft-bodied animals, generally protected by a hard shell (may be reduced or lost as in slugs, octupi) - Includes lots of food (clams, oysters, calamari, escargo), range of eye complexity (octopi are particularly complex with lenses and retinas convergently evolved in a similar structure as vertebrate eyes), larges invertebrates (Giant Squid), high venomous Cone Snails and Blue-ringed Octopus can cause human death in minutes - 40% of recorded animal extinctions have been molluscs (mostly freshwater mussels and snails which are very sensitive to pollution and siltation of rivers)
3 Major Mammal Lineages
Monotremes Marsupials Placental Mammals
Know the relationship between volume and surface area and why it it important in limiting cell size.
More surface area = more absorption of nutrients More surface area = but more volume = less nutrients for center cells
Ectothermy
Most heat gained from external sources. Examples: Most fish, most non-avian reptiles, most invertebrates.
Phylum Porifera - Sponges
Multicellular organisms without tissues, organs, or body cavity - No specialized tissues (some cells are indvidiually specialized but can shift and change function rather than being part of a permanent tissue type), no symmetry - Filter gallons of water a day through their body cavities to catch food particles - Often have added structural support and predator defense from Silica or Calcium Carbonate SPICULES - Internal cells (choanocytes) of many species nearly identical in form to Chaonoflagellates
Ecdysozoa: Phylum Nematoda
Nematoda = Roundworms - Many parasites of plants and animals (including humans!) - Caenorhabditis elgans (C. elegans) is an important research organism: 1st animal genome to be completely sequenced, only 1000 cells
Nervous Tissue - Nerve Tissue
Nerve tissue enables rapid cell-to-cell communication over long distances.
Nitrogenous Wastes
Nitrogenous breakdown products of proteins and nucleic acids must be removed from the body, here are the steps: 1 - Nitrogenous waste forms 2 - Ammonia is toxic, even at low concentrations; require access to lots of water; common in aquatic animals (most fish 'pee' constantly) 3 - Urea produced in liver of some animals from ammonia, much less toxic; carried to kidneys where concentrated and excreted with minimal loss of water; some aquatic animals (sharks), amphibians, mammals 4 - Uric Acid is largely insoluble in water, can be secreted as a paste with very little water loss; reptiles (including birds), insects, land mollusks Disclaimer: Urea and uric acid require spending energy and carbon to produce but allow elimination of nitrogenous waste with far less water loss and toxicity than ammonia
Sponges...
Only have specialized cells with no tissue and no symmetry - ancestral animals may have had symmetry and tissue more like comb jellies than sponges
Open Circulatory Systems
Open systems: invertebrates - insects and other arthropods, most molluscs - Circulatory fluid (hemolymph) bathes the organs directly with no separation from the interstitial fluid - tubular hearts
KSU Owl - Anatomically Incorrect
Owls have huge eyes and feathery facial discs to funnel sound into their ear holes (beneath eyes). Asymmetric placement of earholes means sound reaches one ear a split second before it hits the second, allows an owl to perceive depth perception from sound and hunt in complete darkness if necessary. Owls also differ from other bird of prey lineages in having 2 toes forwards and 2 toes backwards when gripping instead of 3 toes forward and one backward - KSU SPORTS LOGO IS ANATOMICALLY INCORRECT - Curved wings instead of pointy wings! - 2 toes forward and 2 toes backward, not 3 toes forward and 1 toe backward - Owl have tiny eyes (ksu has huge eyes) - feathery facial discs to funnel sound - Asymmetric placement of ear holes
How does Hemoglobin Function?
Respiratory Pigments: Proteins that transport oxygen in the blood. In vertebrates, the respiratory pigment is HEMOGLOBIN, where it is contained on erythrocytes (red blood cells). - Hemoglobin reversibly binds O2: loads O2 in lungs, unloads it in other tissues where CO2 concentration is high and leads to slightly higher acidity. - Hemoglobin binding of O2 to one hemoglobin subunit induces other subunits to bind O2 with more affinity: 4 total molecules of O2 per hemoglobin. - Hemoglobin also helps transport CO2; Carbon monoxide (CO) binds irreversibly, prevents O2 & CO2 transport leading to suffocation.
Archosaurs: Crocodilians
Retain many of the primitive archosaur characters (body like a lizard) - Low diversity today: remaining crocodilians are all semi-aquatic predators: Alligators, Crocodiles, Caimans, Gharial, and False Gharial
Digestion - Pancreas
Pancreas produces protein-digesting enzymes (proteases) activated once they enter the duodenum
Lophotrochozoa: Phylum Platyhelminthes
Platyhelminthes = Flatworms - Simple body plan is probably similar to Acoela and ancestral bilateral animals - Most cells are in close contact with external environment facilitating diffusion of nutrients and wastes - Includes some human parasites (tapeworms, liver flukes)
Immune System: Innate Immunity
Present BEFORE any exposure to pathogens, nonspecific - Barrier Defenses: Mucus, skin (acidic), exoskeleton in insects - Internal Defenses: White Blood cells like MACROPHAGES (eat foreign organisms in response to histamine), Natural Killer (NK) cells (kill abnormal cells), insects produce antimicrobial peptides
Earliest Animals were..
Probably Grastula-like with specialized cells for reproduction (gamete production).
Protostomes vs. Deuterostomes
Protostomes: 1st indentation develops into the mouth, anus develops from 2nd opening Deuterostomes: 1st indentation becomes the anus, mouth develops from second opening
Marsupials and Placental mammals
Share a common ancestor that didn't lay eggs (eggs hatch internally)
Phylum Cnidaria - Jellyfish, Anemones, Corals, and Hydras
Share a common ancestor with other animals that have tissue, but only have 2 tissue layers (endoderm and ectoderm) that can differentiate into muscle, nerves, etc. More closely related to bilaterally symmetric animals than Comb Jellies (Ctenophora) Radial Symmetry - stinging cells called cnidocytes to capture food Wide Range of SESSILE (anchored, non-moving) and floating forms: includes JELLYS FISH, ANEMONES, CORALS, and HYDRA A single opening to a gastrovascular cavity functions as both mouth and anus
Chaonoflagellates
Sister group to animals that are single-celled, sometimes colonial organisms - nearly identical to some cells in sponges
Exchange with the Environment
Size and shape have a direct effect on how an organism exchanges energy and materials with its surroundings Exchange occurs as substances dissolved in an AQUEOUS MEDIUM diffuse and are transported across the cells; plasma membranes Surface is a function of radius or width squared, Volume is a function of radius or width cubed, so diffusion across a membrane can't keep up with volume once a cell reaches a certain size - limits the size of a single-celled organism
Digestion - Small Intestine
Small Intestine is the longest section of the digestive tract; the major organ of digestion and absorption; in the duodenum, acid chyme mixes with digestive juices from the pancreas, liver, & gallbladder
Connective Tissues
Sparsely Packed Cells scattered in an EXTRACELLULAR MATRIX - a web of protein fibers embedded in a liquid, gel, or solid - primarily function to bind and support other tissues Includes: Cartilage, ligaments, bone, fat, and blood
Model Organisms
Species that are easy to raise in the lab and use in experiments - E. coli: model bacteria - Fruitfly: genomic model chromosomal - Zebrafish: vertebrate model organism - C. elegans: 1st animal genome to be fully sequenced - Mice: mammal model organism
Hypothesis - First Branching Lineage of Animals
Sponges are the first-branching lineage of animals - If Ctenophora (comb jellies) are basal animals, it would either mean Sponges and Placozoa each lost nervous system and muscle tissue or that Ctenophora evolved its own nervous system independently from other symmetrical animals.
Digestion - Stomach
Stomach secretes HCl (pH ~2) and the enzyme PEPSIN Stomach lining is coated with MUCUS to prevent gastric juice from destroying stomach cells; H+ and Cl- released separately, and pepsin isn't activated until it enters an acid environment
Digestion - Gallbladder
Stores liver bile salts and releases to act as emulsifiers to digest lipids.
Hormones can have multiple effects
Target cells may differ in their response to the hormone - Same receptors on very different types of cells, cell responses differ - Different receptors on same types of cells can cause vastly different responses
Lobe-Fins: Tetrapods
Tetrapods are terrestrial Lobe-Fins (closest living relatives are lungfish) - Four limbs and hands/feet with digits - Ears for detecting airborne sounds - Plants, fungi, and invertebrate ecosystems were already in place on land when tetrapods crashed the party ~365 million years ago
Secondary Loss
The common ancestor had characteristic but secondary loss gets rid of characteristic
Gastrulation
The process in which a gastrula develops from a blastula by the inward migration of cells - Envagination of blastocoel wall to form the gut cavity where internal digestion will occur
Anatomy
The study of the biological form of an organism
Physiology
The study of the biological functions an organism performs
Arteries
Thicker walls accommodate high pressure of blood pumped from heart.
Veins
Thinner-walled, blood flows back to the heart with help from muscle action, one-way valves.
Reptiles: Archosaurs
Two main extant clades: Crocodilians and Dinosaurs
Capillaries
Very thin walled blood vessels that facilitate exchange with the interstitial fluid - very branched Blood flow is very slow, pressure is low
Neurotransmitter - Glutamate
Vision Constantly released in retinal neurons until stimulated by light. (eyes).
Types of Asexual Reproduction
binary fission budding fragmentation parthenogenesis
intersitial fluid
fluid between cells
circulatory fluids
fluids that move through the body, either freely or within vessels and may transport any of nutrients, wastes, and respiratory gases
Nephron
functional unit of the kidney
African Apes
gorillas, chimpanzees, bonobos, humans
Communication between the presynaptic & postsynaptic neurons...
is most often by way of chemical neurotransmitters
Great Apes
orangutans, gorillas, chimpanzees, bonobos, and humans
Mammals
~ 5,400 species - Mammary glands produce milk for feeding young - Hair for insulation - Differentiated teeth - Warm-blooded - Multiple lineages have gone back to the ocean (Whales/dolphins, manatees, seals, etc.), one origin of true flight (bats)
Homo erectus
~1.9 million years ago - Spread into Europe and Asia out of Africa before the evolution of Homo sapiens - Most successful human species
