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What sensory systems receive signals?

Mechano-receptors include touch, wind, sound
Chemo-receptors include smell, taste
Electro-receptors include light, heat, energy

Sensory Process

Stimulus to sensory neuron
Transduction of energy from stimulus into GP
Transmission of the AP that develops to the CNS
Interpretation of the impulses are qualitatively alike - it's the brain that perceives.

Lateral lines in fishes allow fish to sense objects that reflect pressure waves

By water pressure waves the fish stimulates with pulses.

Hair is a simple solution to many things

Otoliths above hair cells in vertebrates
Tympanum or the mechanism for hearing has evolved many times in animals
Ex. frogs, bats, katydids all different
Loudness depends on the number of hair cells stimulated inside inner ear by sound.

Bats, crustaceans and whales

use sound as radar to determine distance by knowing how long it should take a sound to return to them once it is sent out.

Ampullae are bulbs at the end of the semi circular ear canal

Involved with balance and angular motion.


Contain proteins that bind with chemo-receptors causing depolarization of sensory neurons.

Mollusks, Annelids, Arthropods and Vertebrates developed image forming eyes:

Independently although general design is the same.


Detect low light and require much more of it to activate the AP


Area of keenest vision and require bright light. Only cones and diurnal vertebrates have.

Nocturnal animals often lack cones

See in black and white and use only rods because of low light.

Other sensory modes humans don't have:

Heat sensing organs in pit vipers
Electrical sensing organs in sharks
Some fish navigate using electrical pulses. Electric eels stun food.


Mainenance of constant internal state in organisms.
Essential for proper functioning ranges of pH, temperature, solute concentration.
Challenged by metabolic needs/bi products and by changes in external environment.


Radiation - electromagnetic
Conduction - direct transfer between objects
Convection - movement of gas/liquid
Evaporation - energy needed to transfer from liquid to gas phase.

Warm and cold blooded are outdated terms because

Animals once considered "warm blooded" may not always retain warm temperature.
Animals once considered "cold blooded" may have warm blood at some times.
Endo and Ecto define the source of the heat


Regulate body temperature to external environment.
Insects, reptiles, amphibians, some fish.


Produce heat metabolically and stay within an internally determined range. Birds, mammals, some reptiles and insects. Crocodiles and bees.

Countercurrent blood flow

Wolf example
Blood going to and from the heart is positioned near each other, retains/gains temperature.


Temporary, daily temperature reduction during periods of inactivity. Hummingbirds, bats


Seasonal reduction in metabolism concurrent with scarce food and cold temperature.

Osmotic Balance

Another form of homeostasis, water balance.

Fluids inside are isotonic with sea water

Osmoconformer in marine invertebrates and cartilagineous fishes.

Most vertebrates regulate blood osmolarity to achieve constancy internally.

Osmoreguators Water is lost from respiration, evaporation and excretion while water is brought in from drinking, food and biproduct of Calvin Cycle.

Protonephridium with flame cells

Cells in flatworms that remove metabolic waste using cilia to create a current through tubes.


Network of tubes with cilia draw water through the system

Malpighian tubules

Free floating tubes in body cavity that transport and filter into open circulatory system.

Vertebrate kidney in fish

Marine - smaller, urine more concentrated.
Constantly drinking water because salt content outside is so high. Salt and ions are excreted via the gills.
Freshwater - larger, urine more dilute because they must remove water constantly to keep blood solutes higher as well as transport ions into body.

Cartilaginous fish kidney

isotonic because they retain high levels of urea (100 times more than mammals)

Amphibian and reptile kidney

kidney is similar to freshwater fish in amphibians.
Reptile kidney varies based on environment.

Mammal and bird kidney

Produce urine more concentrated than blood plasma and allow more water to be retained.

Nitrogenous Wastes

Concentrated toxins.
Challenge organisms trying to retain water.
Bony fishes remove waste.
Mammals, amphibians and cartilegenous fish convert and dilute waste.
Reptiles, birds and insects convert wastes to uric acid.

Uric acid

Reptiles, birds and insects as a non-soluable crystal that doesn't weigh as much as liquid.

Mammalian Kidney

Regulates water and removes waste
Filters and recovers water

Glomerulus and Bowman's Capsule

Osmoregulation and recovery of water

Blood enters the mammalian kidney at the

Glomerulus or Bowman's capsule which filters and removes water and small molecules from blood. Filtration continues to proximal convoluded tubual.

Higher concentration in the outer medulla pulls water out

Lower concentration in the outer medulla pushes water in

Nephron loop length

determines how much water is kept in or out. Longer loop means more water is pulled back.

Ascending loop impermeable to water and solutes

but can actively transport them by gradients

Final urine concentration depends on permeability of walls and collecting ducts.

ADH hormone controls when blood osmotic pressure is low ADH is released and increases permeability of ducts (to get rid of water) when blood osmotic pressure is high thirst is stimulated and more water is reabsorbed as urine becomes more concentrated.


less ADH

Solutes outside of collecting ducts cause more water to leave via urine

Final concentration of urine is established in distal loop.

Dinosaur Lineages

Dinosaurs, crocodiles and birds make up the Archosaur lineage of reptiles.


Sauropods and theropods



Class Aves are best defined as

Feathered amniotes (or glorified dinosaurs)


Thoracic vertebrae are fused
Bones are laced with cavities
One way airflow
similar development with reptiles (amniotic egg)
Feathers and flight

Synapsid skulls indicate pelycosaurs of the triassic period were forerunners of:


Features of mammals

Mammary Glands
Placental reproduction (most)
Specialized teeth
Adaptations for herbivory
Hooves and horns


Grasping fingers and toes
Binocular Vision


Nocturnal tree dwellers like lemurs

New World Monkeys

Tree dwellers
Prehensile tail (found in South America)

Old World Monkeys and Apes

Ground and tree
No prehensile tail

Bipedalism in Hominids

Skull inferior
Spine S shaped
Shorter Arms
Shaped pelvis
Femur angled in


Skull posterior
Spine slightly curved
Longer Arms
Longer pelvis
Femur angled out

Molecular evidence shows hominids did not evolve from chimpanzee


Out of Africa three times

Neanderthal to Europe
Java man Australia
Peking man to Asia



Joints and skeletal movement

Ball and socket - hip
Hinge - finger
Gliding - spine
Combination - jaw

Smooth muscle tissue is

Single nucleus
Slow & autonomic control

Cardiac muscle tissue is

Single nucleate
Fast & autonomic control
Cells function as a single myocardium

Skeletal muscle tissue is

Multiple nuclei cells
Fast & voluntary control

Thin actin filaments and thick myosin filaments don't contract during muscle movement, they:

Slide - Overlap during contraction of myofibrils

Myofibrils are long tubes packed inside of muscle membranes made of myofilaments

Contract and shorten during movemen


Small protein disk anchors Actin myofilaments
During muscle contraction Z lines move toward center of sarcomere


Repeating structures between Z lines

Energy for muscle contraction comes from:

Free ATP
Blood glucose
Anaerobic glycolysis

Motor proteins

Convert chemical energy of ATP into mechanical energy during cross bridge cycle.

Cross-bridge cycle

Conversion of chemical ATP ino mechanical energy.
Energized state
Myosin head links to actin
Cross bridge forms
ADP + P release as actin is pulled forward
ADP + P link back to myosin as ATP which causes actin to release.
Hydrolysis (cleavage) of ATP to ADP+P returns to original shape.

Ca++ Excitation contracting coupling

Tropomyosin regulated
Toponin regulates
Together are called the Toponin and Tropomyosin Complex
When nerves signal muscle contraction Ca++ is released exposing binding sites for Myosin.

Nerves stimulate contractions when motor neurons deliver electro-chemical impulses to nerves.

ACh is released across synapse and stimulates muscle to produce an electro-chemical response

Motor units vary in size and have an:

All or nothing response
Are set of muscle fibers innervated (synapse forms) by all the axonal branches of a motor neuron plus the motor neuron itself.

Two factors that influence motor units

Number of muscle fibers each muscle unit contracts
The number of motor units recruited

True or False: Sarcomeres are the organelles responsible for the release of Ca++ into muscle tissue during a muscle contraction

False - it's the sarcoplastic reticulum. Sarcomeres are not an organelle.

Central Nervous System

Spinal Cord

Peripheral Nervous System (PNS)

Sensory or afferent neurons detect and transmit to brain
Motor or efferent neurons take message from brain to somatic and autonomic nervous systems.

Neurological cells are Scwann and Oligodendrocites

Responsible for the myelin sheath around axon of some neurons.
Promote salatory transmission of action potentials along axons.

First event in axon of neuron stimulated to produce an action potential:

Voltage gated ion channels in the cell membrane open, allowing Na+ ions to enter the cell and initiate depolarization.

Resting membrane potential is the electrical gradient between a neuron at rest and its surrounding environment.


A threshold of depolarization must be reached before an action potential is initiated in a neuon.


During an action potential the magnitude of depolarization is unaffected by stimulus intensity.


Once initiated an action potential moves along the axon like a self-propagating wave.


Fixed anions are less concentrated inside a neuron than in the surrounding enviornment

False - they are more concentrated inside a neuron than surrounding environment.

What influences membrane potential?

Sodium potassium pumps, ion channels

Resting membrane potential is

-70 mV

Every 3 Na+ in

2 K+ out but Na+ has no net movement because the anions like K+ and concentration gradient lets it back through.

Salatory Conduction

Occurs along an axon with mylenated sheath by jumping nodes of ranvier and minimizing the amount of charge change required.

Conduction velocity

Function of axon diameter and presence or absence of mylen sheath.


space between neuron communication with other cell types.
Intercellular junction with dendrites
Intercellular juntion with muscle cells
Intercellular junctions with gland cells
May be electrical or chemical

Signals and muscle contractions are all just

Cascade reactions regulated by enzyme digestion and re-uptake of neurons.

Phylogenetic Tree

Protostome and Deuterostome
Molting (ecdysis)
Water Vascular System

Features of Animals

Multicellular heterotrophs
No cell walls
Active movement (in many)
Diverse in form and habitat
Sexual reproduction (in many)
Similar embryonic development across taxa
Tissues (in most)

Parazoans and Eumetazoans

Parazoans don't have tissues and are cell aggregates.
Phylum Porifera are Parazoans.
Eumetazoans have tissues and include all the other animals (most)
Phylum Cnidaria are Radiate Eumetazoans.
Phylum Ctenophora have showed evidence of bilateral symmetry.


Most bilateral
Spiral cleavage


Echinoderms & Chordates
Radial cleavage

Body cavities have played a pivotal role in evolution and animal complexity, why are they not defining characteristics on the phylogenetic tree?

They aren't very informative about evolutionary relationships.

Bilateral Symmetry has ______ tissue layers and is triploblastic.

3 (Ectoderm, mesoderm, endoderm)







Phylum Ctenophore

No polymorphisms



Bilaterian Acoelomates

Platyhelminthes have a digestive, exretory and nervous system.
Turbellarians are bilaterian acoelomates


Phylum Nematoda

Pseudocoelomate evolutionary history

More than once

Segmentation evolutionary history

More than once

Coelomate Invertebrates

Annelida and Mollusca

Body plan of mollusks

Radula (most)

Annelida and Mollusca larvae are both

Trochophore larvae

Characteristics of Arthropods

Jointed appendages
Chitin exoskeleton
Open circulatory system
Two-stranded ventral nerve
Compound eyes
Variable excretory system

Malpighian tubules are found in

Insects, chelicerates and myriapods

Arachnids have

2 tagmata
1 pair of pedipalps
4 pairs of walking legs










Each thoracic segment has one pair of legs
Ecretion of nitrogenous waste is achieved via malpighiantubules
Wings, when present are located on the second and third thoracic segments only
Insects must molt to grow
A chitinous exoskeleton covers the body


Shrimps, lobsters, crayfish and barnacles
Jaws are mandibles for chewing
Chephalothorax & abdomen
10 pairs of jointed apendages
Breathe through gills

Evolutionary split between protostomes and deuterostomes

Echinoderms and Chordates are the only deuterostomes with radial cleavage.

Phylum Echinodermata

Water Vascular System
Bilateral symmetry until adults
Nerve ring with 3 layers but no brain
Epidermis over endoskeleton of ossicles

Four hallmark features of Phylum Chordata

Hollow dorsal nerve cord
Pharyngeal gill slits
Post anal tail

Features of Vertebrates

Vertebral column (in most) replaces the notochord
Cranium encases brain
Neural Crest
Complex internal organ systems - closed circulation
Pharyngeal gill slits become feeding instead of respiration
Endoskeleton completely within the body

Endoskeleton development

Ossification - from cartilage to bone

Five features of fishes

Internal gills
Jaws & paired appendages
Vertebral column
Single loop blood circulation (only in fish)
Nutrient deficiencies

Extinct fishes

Placoderms, Ostracoderms, Acanthodians


Jawed fishes
Myxini (hagfishes)
Cephalospidomorphi (lampreys)


Cartilaginous fishes
Oil in liver
Do not have a muscular operculum

Actinopterygii and Sarcopterygii

Bony fishes


Have legs in their ancestry
Lobe-finned fishes linked by fossil Tiktaalik
Have evolved more than once

Amphibian Features

Lungs (most)
Cutaneous respiration (only amphibians)
Double loop blood circulation
3 chambered heart (most)

Reptile Features

Amniotic egg (mammals and birds)
Dry, water tight skin (not cutaneous)
Thoracic breathing

Spore versus Seed

Spores are single celled and haploid.
Seeds are multicelled and diploid with a protective coat.



Characteristics of Bryophytes

Non Vascular
Small and herbacious
Gametophyte, haploid one n generation is dominant.
Require water to reproduce



Characteristics of Tracheophytes

Carboniferous period: 360 - 290 MYA
Vascular tissues
Lignin in cell walls
Ariel portions are cuticle and stomata
Sperm have flagella and require some water to reproduce
Sporophyte, diploid, two n generation becomes dominant generation

Which of the following adaptations of land plants distinguish them from their algal ancestors?

(c) Embryo stage in their life cycle
(c) Vascular tissues


3.5 - 3.8 BYA
Live everywhere
Most abundant organisms

Prokaryote Classification

Molecular approach
DNA nucleotide sequences
Many unknown species
Most bacteria are unknown (not cultured)

Prokaryote Structure

1 - 5 micrometers
3 basic shapes - rod, spheres/ovals, spirals
Cynobacteria may be in colonies with a biofilm of polysaccarides

Cyanobacteria Colonies

True colonies are permanent groups
2 + specialized
if cells in a colony are separate they can survive

Most bacteria have cell walls for:

Prevent bursting

Archaea vs. Bacteria cell walls

Archaea: cell walls are various cell walls
Bacteria: cell walls are peptidoglycan, long sugar chains

Gram (+) positive

Thick peptidoglycan llayer and plasma membrane. Penicillan blocks layer linking so the stain gets in.

Domain Bacteria are:

Prokaryotes that live in normal environments. Include traditional bacterias.

Domain Archaea

Prokaryotes that live in very extreme environments. Includes halophiles, thermophiles, extremophiles and methanogens.

Kindoms inside of Domain Eukarya


Characteristics Domain Archaea

Unicellular (circular DNA) extremophiles
No nuclear envelope
No peptidoglycan in cell walls
Lipid structure is different
Genes may have introns
+1 or more RNA polymerases


Members of Domain Archaea
Anaerobic only.
Live in swamps, marshes and intestines.


Members of Domain Archaea
Thermophiles (cold/heat adapted)
Halophiles (salt)
pH tolerant
Pressure tolerant

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