Animal Biology Flashcards
what is an osmoconformer
an organism that keep their internal fluids isotonic to their environments. Their internal salinity is the same as the water they are in often marine creatures
Define osmoregulators
organisms that actively regulate their osmotic pressure independent of their surrounding environment often freshwater
define homeostasis
the maintenance of relatively stable physical and chemical conditions of internal body fluids
why do organisms osmoregulate
organisms are open systems that exchange matter to maintain homeostasis
what are the osmoregulatory organs
gills - ionic fluxes, passive water movement
kidney - ultrafiltration, urine production
intestine - water absorption
what is the hydromineral regulation
the active regulation of osmotic pressure of body fluids so that homeostasis is maintained by the excretory systems
what are the principal waste products of animal metabolism
water, carbon dioxide, nitrogenous wastes (ammonia, urea, uric acid)
what are the excretory organs of invertebrates
Protonephridia, metanephridia, Malpighian tubes
what are Malpighian tubes
extensions of the gut wall
They are blind ends that lie in the hemocoel that are actively transport uric acid (etc) into the tubule which then passes into the gut and water
why must terrestrial vertebrates conserve water
high metabolic rate leads to large volumes if nitrogenous waste. Kidneys and other adaption conserve water
how does the vertebrate kidney work
functions in excretion and osmoregulation. Its vital to maintaining homeostasis. Its a key organ in the urinary system
how is urine formation accomplished
filtration of plasma which reabsorbs needed materials and secretes other substances
what hormone regulates urine volume
Antidiuretic hormone (ADH)
What is a circulatory system and what is it for
It is a system of blood vessals or spaces through which the blood can flow. Includes the heart, arteries etc. Delivers oxygen to cells and removes waste
describe open circulatory systems
blood is not confined to closed vessels and blood tissue exchange happens in tissue spaces called lacunae
many are organized channels through certain organ e.g. gills
what is the pericard
the vessel from each gill to heart atria. The blood from the gills collect hear and enter through the dorsal ostia
what are the problems with the open circulatory system
difficult to accurately regulate
sluggish
describe the closed circulatory system
in organisms with higher metabolic rate and contractile vessels and accessory hearts. Its always contained with in the vessals
Describe a single loop blood circulation system
in fish its a single loop system which limits rate of oxygen delivery and has low blood pressure but allows blood to be fully oxygenated leaving the gills. The heart is a tube pump
describe amphibian and reptile hearts
three chambered. Pulmonary and systemic circulation
It allows for higher blood pressure but no complete separation of vertices
describe the circulatory system in mammals and birds
four chambered. pulmonary and systemic
Advantages include complete seperation continuous perfusion of lungs and increased efficiency
what is the endocrine system
hormone and chemical signals that regulated almost every biological process including growth and development, mental development, mood, memory, sexual maturation, immune functions
what are the classes of hormones
steroids derived from cholesterol, amine derivatives and, peptides and proteins
how does the endocrine system work
hormones travel through blood until they reach their particular receptor cell. They then turn on or off functions which triggers a reaction
what are endocrine disrupting chemicals
man made compounds which fit into hormone receptors blocking normal hormones or acting instead of the hormone. AKA drugs
what are circulating hormones
hormones translated by the blood and bind to receptors on distant cells
what are local hormones
paracrine hormones which bind to receptors on nearby cells
Autocrine hormones that bind to receptors on the same cell that secretes them
what is ecdysis
Molting - necessary for crustacean to increase in size as their exoskeleton does not grow. The physiology of molting affects reproduction, behavior and many metabolic processes
what causes ecdysis
molting animals grow in the intermolt phases until their is no space within the cuticle. This is the pre-molt phase.
how does hormones control ecdysis
ecdysis is started by CNS which is triggered by temperature, day length r other stimuli trigger. CNS decreased production of molt inhibiting hormones which promote release of molting hormone
how do eyestalks affect molting
accelerates it and prevent colour change to match background as eyestalk hormones control dispersal of cell pigments
what is an Endocrine Disrupting Chemical (EDCs)
a chemical that interferes with the synthesis, secretion, transport, binding, action or elimination of any hormone in the body
what are some known sources of EDCs
Pesticides, plastic leaching, drugs (e.g. birth control), industrial chemicals, household products such as detergents soaps and cleaners and, heavy metals (lead, mercury etc.)
What can EDCs link to
Reproductive disorders, immune system dysfunction, certain cancers, low iq
What is nonylphenol (NP)
added to pesticides and detergents to make chemicals work better in water. It is suspected if feminizing male fish in rivers
describe muscle physiology
macroscopic structure made of cellular and subcellular units.
In charge of body movement, respiration, heart beat, production of body heat and more
what is excitability in terms of muscle physiology
capacity of muscles to respond to a stimulus
what is contractility in terms of muscle physiology
ability of a muscle to shorten and generate pulling force
what is extensibility in terms of muscle physiology
muscle can be stretched back to its original length
what is elasticity in terms of muscle physiology
ability of muscle to recoil to original resting length after stretched
What are the 3 types of muscle
Skeletal, smooth and cardiac
describe skeletal muscles
muscles that are attached to bones. responsible for locomotion, facial expressions, respiratory movements. Controlled by somatic motor neurons
what is perimysium
collagen and elastic fibres surrounding a group of muscle fibres called a fascicle
contains blood vessels and nerves
what is endomysium
loose connective tissue that surrounds individual muscle fibres
what are sarcomere
the basic unit of contraction of skeletal muscles
what are z discs
the boundaries of each sarcomere
what are actin filaments
think filaments that extend from Z disc toward the centre of the sarcomere
what are myosin filaments
thick filaments located in the centre of the sarcomere
what are A bands
full length of the thick filaments includes inner end of thin filaments
what is the H zone
centre part of A band where no think filament occurs
What is the I band
region with only thin filaments
What is the relaxed and stimulated state of muscles
when thin and thick filaments only slightly the muscle is relaxed. Upon stimulation myosin head bin to actin and thin filaments slide past thick one so that the filament overlap to a greater degree
describe smooth muscles
grouped into sheets in walls of hollow organs. Participate in peristalsis.
what is the longitudinal layer
muscle fibres that run parallel to the organs long axis
what is the circular layer
muscle fibres that run around circumference of the organ
what are the 4 fs
Fighting, fleeing, feeding and FUCKING
Describe cardiac muscles
only found in the heart where it forms a thick layer called the myocardium.
Made of striated fibres that branch and each cell usually has one or two centrally located nuclei
What is bioelectricity
like all cellular organisms humans run on electricity. Slight imbalances of electric charge charges across membranes result in sensation, movement, awareness and thinking
What is the nervous system
translate sensory information into action potentials and process APs into adaptive response
what are the major components of the immune system
physical barriers, cells and tissues, soluble factors
What is a reflex arc
The most basic pathway
Sensory neuron controls effector cell directly
Define phagocytosis
Basic immune response evolved from feeding by protists - and underpins many immune developments and is in all animal groups
What are the three main stages of cell response
Recognition, communication, and response
define acoelomates
includes sponges, cnidarians, flatworms. They are filter feeders, carnivores or absorbers. They blood or immune system or specialized immune cells. Their threats are microbes in water
What are Fibrinogen Related Proteins (FREPs)
Highly variable proteins that are up-regulated in gastropods following parasitic infection.
The protein binds agglutinates and kills sporocysts in hemolymph
What are allogeneic interactions
Allogeneic = different genotypic individuals
their interactions can be to tolerate, to attack each other and fuse
what is a phylum
a major group of animals thought to share a common evolutionary ancestor.
Usually based on similarities in morphology, body and or similarities in development and embryology. Increasingly based on molecular evidence.
how many phyla are there
approximately 35
where are the porifera (sponges) phylum found
virtually all are found in ocean. Most are subtidal. Tend to be abundant in areas with fast currents as they are filter feeders
What do porifera look like
Usually irregular and vary variable in shape
They can be thin crusts, thick encrusting lobes, vase shaped, spherical, irregular, basket shaped.
Glass sponges have been found in deep sea
what are the characteristics of porifera
No true tissues organs, gut or nervous system.
Cells loosely aggregated and have high regenerative potential
Asymmetrical or radially symmetrical
Current flows though pores, canals and chambers throughout body
chamber lined with flagellated cells
possess an internal skeleton of spicules and or organic fibres
where are the Cnidaria (jellyfish, sea anemones, coral etc.) phylum found
virtually all found in sea
most are subtidal some found at shore
Tend to be abundant in areas with fast currents because they are filter feeders
What does Cnidaria look like
Usually radially symmetrical, Have a diverse range of body forms. Tends to be better defined than sponges
Have 2 main body forms - polyps and medusae (some species have both)
Describe polyps
A fixed cylindrical structure that symbolizes an asexual phase
many species are formed from a colony of many connected polyps (most corals)
Describe medusa
a free-swimming umbrella like structure that represents the sexual stage
What are nematocysts
Stinging cells that are one of the main features of the phylum. Venom can be highly toxic and cause fatalities
What are the Cnidaria characteristics
Mostly marine
Cell wall differentiated
Body wall is three layered
Mouth is generally surrounded by tentacles
They have two main structures (polyp and medusa)
Alteration of generations
Posses nematocysts
Describe the super-phylum Arthropoda
Chitin exoskeleton which is periodically moulted, segmented body, jointed with paired appendages
Sexes usually separated
Millions of species
Made up Chelicerata (scorpions, spiders), Uniramia (insects, millipedes and centipedes), and Crustacea (crabs, lobsters, shrimp)
Describe the Chelicerata (scorpions, spiders etc.) phylum
Made up of 3 main classes: merostomata - horseshoe crabs (4 species), arachnida - scorpions, spiders, ticks etc. (over 70,000 species) and pycnogonida - sea spiders (over 1000) species
Describe Scorpionidae order
Terrestrial present in all continents. Abudant in tropical and subtropical regions. Nocturnal, carnivorous. Uses sting which injects neurotoxins to kill prey. Over 3000 species
Describe the Araneae order
Approx. 50000 species made up of around 20 species. Mainly terrestrial. Usually predators of arthropods. Have poison glands associated with chelicera, digest prey externally and ingest fluids.
Describe Chelicera
a pair of appendages in front of the mouth in arachnids and some other arthropods, usually modified as pincer-like claws
How are arachnae usually divided
Broadly divided into web builders and hunters. But can be broken down into further families
Hunters have thicker legs and highly developed eyes
Builders have long slender legs and exceptional detection of movement as well as poor vision
How do Araneae reproduce
they have separate sexes. They have paired gonads in abdomen and genital openings on ventral surface. The males use pedipalps to transfer sperm receptacle.
describe the Opiliones order
7000 species. Abundant in vegetation prefers humid conditions. Does not spin silk, non-venomous 1 pair of eyes, omnivorous or scavengers
Describe order Acarina
Includes mites and ticks. Approx. 30000 species although this is thought to be less than 50% of the actual number. Largely terrestrial. Economically important because of food/crop damage and parasitism. Unsegmented abdomen
Describe the Pycnogonida class
Marine (known as sea spiders) 1000 -1300. Small no antennae, up to 6 pairs of legs. Possess chelicerae and palps
Describe the Platyhelminthes Phylum
Made up of Turbellaria - mostly free-living flatworms (~3500 species), Trematoda - flukes (~12500 species), and Cestoda - tapeworms (~3500 species). Last 2 are entirely parasitic and derived from the first
What are the main characteristics of Platyhelminthes
They have bilateral symmetry
a sac like or branched blind ending gut
no segmentation, no body cavity, no circulatory system, circular and longitudinal muscles
how do platyhelminths reproduce
Most are hermaphrodites. Eggs maybe entolecithal or ectolecithal. Sometimes a larva but sometimes direct development. Some reproduce asexually by fission
Describe the importance of the Annelida phylum
Polychaetes are one of the major groups of marine macrofauna of marine sediments
Terrestrial oligochaetes (earthworms) feed on dead organic matter and are of enormous importance to the ecology of soil.
Leeches are used for medical purposes
what are chaetae
bristles made of chitin used for burrowing, swimming or anchoring the body
What are the characteristics of Polychaete
Parapodia - the fleshy protrusions on the sides of some marine gastropods
Numerous and relatively complex chaetae and structurally diverse.
What are the types of polychaete
Errant - free moving
Sedentary - burrows, tube dwellers
~8000 species in total
Describe oligochaeta
Sub class although sometime still referred to as a class
Relatively few simple chaetae
Hermaphrodites. Lay small numbers of large eggs and make cocoons for protection
Describe Hirdinea
Sub-class
No chaetae
Suckers at both ends
Body is a single hydrostatic unit
Hermaphrodites
Eggs laid in cocoon
What is the importance of Mollusca
useful resource - oyster and mussel farming, scallop + squid fisheries, pearls
Pests - shipworm vectors, agricultural pests
Ecological - living reefs, grazers
Define the Aplacophora class
worm like body no shell but covered in calcareous spicules. ~250 species
Describe Monoplacophora class
~12 species. All marine and deep sea - limpet like appearance and thought to be most primitive mollusc group
Describe Polyplacophora class
All marine, mostly grazers in shallow water. shell consists of 8 overlapping plates bound together. ~800 species
Describe Scaphopoda class
Tusk shells, all marine, live in sediments, shell consists of a long tube open at both ends. ~350 species
Describe Bivalvia class
Clams and stuff. Mostly marine, some freshwater. Most are burrowing filter feeders. Shell consists of two valves connected by flexible ligament. ~10000 species
Describe Gastropoda class
Include snails and slugs. ~60000 species - most diverse of the molluscan groups, marine, freshwater, and terrestrial. Many are grazers
Describe Cephalopoda Class
Squid, octopus, cuttlefish etc. ~650 species
most highly evolved of the molluscan groups.
All marine, mostly active swimming predators. Shell is generally absent or greatly reduced/internal.
How many classes of Mollusca are there
6 - Aplacophora, Polyplacophara, Gastropoda, Scaphopoda, Bivalvia, Cephalopoda
Describe the subphylum Crustacea
Segmented body (head, thorax, abdomen). Biramous appendages. Many species have compound eyes and complete visual units
Describe the general internal anatomy of crustacean
Gas exchange via gills
Gut lined with chitin and comprised of fore-, mid-, and hind-gut
Digestive glad synthesizes and secretes digestive enzymes
How do crustacean reproduce
Usually separate sexes although a few are hermaphrodites. They have specialized appendages for mating and egg brooding. Eggs hatch into larvae
What are the 3 main classes of crustacea
Malacostraca, Copepoda, Cirrepedia
Describe Malocostraca class
~40000 species.
Diverse body forms, thorax bears legs, abdomen bears pleopods and uropods
Describe Eucarida super-order
Part of Malocostraca class. Main characteristics are that they have a large carapace, fused dorsal to all thoracic segments, stalked eyes and swimming larvae. Order includes decapods
Describe Peracarida Super-order
Key characteristics includes no/reduced carapace meaning segments are visible from above.
They have brood pouch meaning larval stages often absent. Includes isopoda and amphipods classes
Describe order decapoda (crabs)
Have 10 legs including pair of pincers
Have seperate sexes
Describe order Amphipoda
laterally flattened, compound eyes, mostly marine, some burrow or live in tubes, omnivoirs
Describe order isopoda
Dorsal ventrally flattened. Mostly marine but also the most successful terrestrial crustacean order.
Many parasitic species (host usually fish). Suck blood causes tongue to atrophy
Describe Cirrepedia class
Barnacles - highly modified body all barnacles are sessile some are stalked
What are the main characteristics of Arthropods
Segmented body, jointed appendages (legs), chitinous exoskeleton called cuticle which molts and a tagmatised body (2 or 3 regions)
What are the main arthropod body plans
Uniramia, Chelicerata, Crusacea, Trilobita
Describe Uniramia plan
One pair of antenna - includes insects and myriapods (centipedes and milipedes)
Describe Chelicerata plan
No antennae - includes spiders, scorpions etc.
Describe Crustacea plan
Two pairs of antennae - includes crabs woodlice etc.
Why are insects important
Pollinate 2/3rds of all flowering plants
Produce resources like honey :)
Can be pests to crops (locust, aphids, etc.)
Pests of livestock (warble fly, bot fly etc.)
Disease vectors - Malaria, bubonic plague etc.
Can be a nuisance (midge, European wasp etc.)
Talk about insect diversity
Massively diverse with over 1 million described species. There is an estimated 30 million species with about ~35 orders.
Coleoptera (beetles) are the most species rich order ~350000 species
Describe insects body plan
The head has one pair of antennae and compound eyes
Thorax has 3 pairs of legs and 3 pairs of wings
Abdomen has the reproductive structures
They have a waxy epicuticle that has hardened scleritis and flexible sutures
Respiration done by tracheal system
Describe Entognatha
Eversible mouth parts contained in a pouch - made up 3 orders of primitive insects lacking wings (~10000 species)
Describe Ectognatha
external mouthparts - winged or wingless - all other insects (~1 million species)
Describe Pterygota
sub group of Ectognatha (~1 mil. species)
Main groups include Palaeoptera (dragonflies ~5600 spp., mayflies ~3100 spp.,) whose wings are flattened or upright at rest
Neoptera - wings are folded or flexed at rest - includes all other insects
Describe Apterygota
Primitive insects lacking wings. Sub group of Ectognatha (~1000 spp.)
Define Neoptera
Polyneoptera have broad fan like extension to hind wings - earwigs cockroaches, grasshopers etc.
Paraneoptera
Disparate group that united on morphological and molecular character - true bugs (Hemiptera) are the biggest order with ~100000 species
Describe Endopterygota
Have complete metamorphosis - known as the higher insects
Major orders include Coleoptera (beetles ~350000 spp.) Dipetera (True flies ~152000 spp.) Hymenoptera (bees wasps, and ants ~150,000 spp.) and Lepidoptera (Butterflies and moths ~160000 spp.)
How does insect flight work
Direct flight muscles - have 1:1 relationship of nerve impulses to muscle contractions (dragonflies or cockroaches)
Indirect flight muscles - have faster wingbeat. Muscles contract in response to a tug and will oscillate (smaller insects)
Describe insect feeding adaptations
Consists of 3 pairs of appendages that are highly versatile. Adapted for chewing, piercing, nectar collection, liquid feeding, predation etc.
What are pheromones
substances secreted to outside by an individual and received by a second individual of the same species
Give some examples of pheromones
Midges – release pheromone to attract others to blood meal
Wasps, bees etc release an attack pheromone
Moths – females attract mate by releasing a pheromone
Insects that deposit larvae in fruit – pheromone deterrent to competition
Ants – trail following pheromone
Pheromones are used for pest control
Describe the Bryozoa phylum
~5000 spp. mostly marine
Colonial, made up of small zooids which are often polymorphic.
Their bodies are composed of trunks and eversible introvert bearing lophophore
Describe lophophore
Circular or U shaped fold of body wall bearing ciliated tentacles
The cilia drive water currents for filter feeding
Describe Cilia
Hair like projections that move microbes and debris up and out of airways
Describe the Bryozoan colony form
Most species lack stolons and zooids in direct contact with each other.
Crusts are the most common growth form - on various surfaces including algae
Describe different forms the zooid colony can take
coral-like growth form
seaweed-like growth form
crust growth form
Talk about Zooid polymorphism
Most species have colonies composed of different types of zooid including autozooid, heterozooid, kenozooids, avicularia, vibracula and ovicells.
Describe autozooid
typical feeding zooid which makes up bulk of colony
Describe heterozooids
Zooids which are reduced or modified for various functions
Describe kenozooids
Form stolons (attachment disks or rootlike structures)
Describe Avicularia
Defensive structure modified to form powerful ‘jaws’. usually smaller than autozooids
Describe Vibracular
Operculum modified to form long moveable bristle. Usually function is to sweep away silt or other fouling material
Define Gonozooid
Zooid modified to form chamber for brooding eggs/embryos
Describe Ovicell
Part of autozooid modified for brooding eggs
Describe Echinodermata phylum
Made up of 5 classes
Radial symmetry in adults, bilateral in larvae
Have water vascular system, endoskeleton, mutable connective tissue, regular and irregular echinoids
~6000 spp.
What are the Echinoderm classes
Asteroidea - starfish, sun star etc.
Crinoidea - crinoids and featherstars
Ophiuroidea - brittle stars
Echinoidea - sea urchins, sand dollars etc.
Holothuroidea - sea cucumbers
Describe class Asteroidea
~1500 spp. in mainly coastal areas.
Most species are pentamerous but some have more than 5 arms
Describe the water vascular systems
Systems consist of a network of internal ciliated canals linked to tube feet (podia) which are muscular and can bend in different directions typically with a sucker at the tip
Describe the Asteroidea mouth structure
Mouth is on underside and termed the oral surface. Upper surface is the aboral surface
Ambulacral grooves along oral surface of arms have 2 or 4 rows of tube feet
Describe class Echinoidea
No arms - body circular or oval
Skeletal ossicles interlinked to form a solid test. Surface covered by movable spines ~950 spp.
Describe Asteroidea endoskeleton
lattice of rods and plates bound by connective tissue which can be stiffened or softened as required
Formed from magnesium rich calcite
How do Asteroidea feed
Many feed of bivalves
Tissue stiffens and skeleton becomes rigid scaffolding enabling to use hydraulic force of the tube feet to pull open valves of bivalve prey enough to insert eversible stomach and begin digestion
Describe Ophiuroidea class
Many live in crevices of one sort or another very abundant in fast current areas.
Similar body shape to asteroids but arms are more separated from centra disc and have more solid structure. ~2000 spp.
Describe Holothuroidea class
~900 species, body is cylindrical. Tube feet around mouth highly modified as buccal tentacles and often branched. They are deposit and suspension feeders
Describe Crinoidea class
An ancient and primitive group of echinoderms
Only class where oral surface is directed upwards. Include attached sea lilies ~80 modern species and feather stars ~550 spp.
Describe Ascidian class
They have chordate characteristics (like tadpoles). They are free swimming larva with notochord and neural tube
Adults are sessile, they have solitary and colonial forms
What is the importance of fish
Evolutionary -first lineage of vertebrates
Super diverse (~30000 spp.) most diverse vertebrate
Great food source - fisheries and aquaculture
Also provide other products
Describe the external anatomy of fish
Scales, lateral lies, fins, gills
Describe Class Amphibia
~4000 species
Legs
Lungs
Permeable skin
May produce noxious or toxic secretions
Partially divided heart (2 atria)
Ectothermic
Metamorphosis from aquatic juvenile to terrestrial adult
What are some key evolutions of fish
Jaws + protrusible jaws - derived from anterior gill (evolved in fish initially)
Fine scale maneuverability
What are the origins of amphibians
Derived from lobe finned fish - sarcopterygians (e.g. coelocanths) which evolved into early Tetrapods which made their way onto land. One branch of these gave rise to amphibians whilst another gave rise to reptiles which in turn gave rise t mammals, modern reptiles and dinosaurs, some of which evolved into birds
Describe amphibian life cycle
Egg mass -> tadpole -> tadpole with hind legs -> young frog with 4 legs and short tail -> adult frog YIPPEE :)
Define the main characteristics of Anura
No tail
Vocalization
Some brood eggs away from water
Carnivorous
Inflate or release toxins for defense
Feed using catapult action with tongue
What are the major groups of Amphibians
Anura (~3500 species of frogs and toads), Caudata (~360 species of newts and salamanders) and Apoda (~200 species of caecilians)
Describe Caudata characteristics
Have head, trunk and tail. Mostly in new world and northern hemisphere
Pedomorphosis common
Define the main characteristics of Apoda
eyeless - eyes cover by skin or bone but have normal retina and photoreception
Legs and pectoral and pelvic girdles lost
Some have scales
Burrowing or aquatic
Why are amphibians in decline
Over 30% are threatened with 120 species extinct since 1980s
Habitat loss
pollution of freshwaters
Disease (chytridiomycosis-fungus)
Climate change
+ more
What are the main characteristics of Reptilia
~7000 species
Scales cover body which are periodically shed
Shelled amniotic eggs
Internal fertilization
Ectothermic
Describe the amniotic egg
Truly terrestrial animals need freedom from the need to lay eggs in/near water. The amniotic eggs allowed this. These eggs are enclosed and contained in necessary watery medium
Describe Chelonia
Turtles - marine, legs modified as flippers (limited mobility on land) only come ashore to lay eggs
Terrapins - freshwater living, legs modified for swimming but can move well on land
Tortoises - live on land and can grow very large
What orders make up Reptilia
4 orders
Chelonia (turtles, tortoises, terrapins ~250spp.)
Rhynchocephalia (tuatara ~2 spp.)
Squamata (lizards and snakes ~6800 spp.)
Crocodylia (crocodiles ~25 spp.)
Describe Rhynchocephalia
Tuatara - looks like large lizards but different evolutionary lineage
Large, long lived, sole descendants of ancient group of reptiles.
Describe Squamata
Lizards and snakes
Very diverse group. Lizards typically have legs and eyelids whereas snakes lack these.
Describe Crocodylia
Crocodiles YIPPEE
Large predators. They have diaphragm and 4 chambered heart
Describe Reptilia’s relationship with venom
Many snakes have a venomous bite for prey capture or defense. It is a complex mix of chemicals specific to particular species. 50-60000 human deaths a year from snake bites.
Some lizards have venomous bites too like the komodo dragon
Define Aves class (birds)
~10000 species. They fly with feathers. Amniotic eggs
Fully divided heart (4 chambers)
Single pass cross-current lungs
Endothermic
Specialized beak
Describe evolutions in modern birds
Enlarged braincase
fusion of bones (hands become wings, pelvis and tail fuse together)
Enlarged sternum
Strengthening of ribs
Describe how bird have adapted for flight
Greatly enlarged sternum for attachment flight muscles. Fused pelvic girdle for strength and muscle attachments
Bones are lightweight - hollow with rods and struts to maintain strength
Pectoral muscles provide down stroke
Feathers are modified scales
Describe birds lungs
Highly efficient lungs
One way system with air sacs that act as storage reservoirs. Fresh air is passing through the lungs during both inspiration and expiration
Describe bird beaks
No teeth (except in chicks) highly adapted for various feeding modes (seeds, filter-feeding, carnivory, insects, grazing etc.)
Describe the Chordata phylum
They have pharyngeal pouches which open to the exterior as slits. If permanent they live in water and breath through them if temporary they live on land
They have notochord - cartilaginous rod of cells
Describe the Mammalia class
~5000 species and 26 orders
Endotherms, hair, production of milk, 3 bones in middle ear
What are the main characteristics of class Prototheria
5 living species (4 echidna, 1 platypus)
Teeth absent
Single opening (cloaca)
Lay and brood eggs
Mammary glands exude milk
Platypus have poisonous sours on hind feet
Describe sub class Theria
~250 species. Marsupials. Maternally derived shell membrane. Towards end of gestation the shell membrane is absorbed, placenta present for last few days.
Newborns are small
Describe Rodentia class
Most numerous (making up ~40% of mammals). Native to most parts of the world. Have highly specialized dentures. Mostly herbivorous. Can be disease vector
Describe Chroptera (bats) class
Only flying mammals
2nd most numerous (~20%)
Arms adapted to form wings
Hunt using echolocation
Host for many viruses
Describe Lagomorpha (rabbits, hares etc.) class
~80 species
Native to all continents except Australia and Antarctica.
Most fertile mammals
Double digestion
Describe Eulipotyphla (hedgehogs, moles etc.)
Global distribution mostly insectivorous, mostly terrestrial. Some highly specialized for borrowing (e.g. star nosed mole)
Describe Perissodactyla (Horses, zebra, Rhino etc.) class
Odd-toed (middle toe larger than others) Most species have 3 digits on hind foot some only have 1 remaining
Describe Cetariodactyla (camels, whales, dolphins etc.)
Can be terrestrial or aquatic. Whales/dolphins have no hind legs but vestigial structures remain on skeleton
Describe Proboscidea (elephants)
2 living species
Largest land mammals
Trunk used for feeding/drinking
Herbivores
Asian elephants have small ears a twin dome head and only males have tusks
African elephant have large ears a rounded head and both sexes have tusks
Describe the Hyracoidea (Hyrax)
Phylogenetically close to elephants. Posses two continuously growing incisors that resemble tusks
Poor thermo-regulation so spend 95% of their time sun bathing
Herbivorous
Describe the Sirenia (manatees and dugongs)
4 species, totally aquatic, slow moving. Found in warm shallow water
Mostly herbivorous but sometimes eat shellfish or dead fish
Describe the Xenartha (armadillos, sloths etc.)
Linked by specialization of vertebrate which bear additional articulations
Describe Pholidota (Pangolins)
7 species native to tropical regions of Africa and Asia
Have no teeth and possess long muscular tongue (mostly eat ants)
Can be arboreal or terrestrial
Describe the Carnivora (cats, dogs, bears etc.)
Teeth highly specialized for killing/cutting
Native to all major land masses
Some also aquatic (e.g. seals, sea lions)
Describe Primates (monkeys rahhhhh)
~233 species
habitats varied (many live in tropical forests)
Large variance in size
Talk about mammalian hair
They have a versatile array of derived structures (hair, glands) which serves as insulation
Talk about mammary glands
Mammary glands classified as apocrine (secretions produced in membrane bound vesicles budded from plasma membrane)
Derived from paired ridges of foetal epithelium
Development under hormonal control
Describe mammal sweat glands
Sweat glands are derived from epithelium. Can be classified as apocrine or eccrine
Eccrine - Widely distributed, secreted directly to skin
Apocrine - restricted to armpit, genital areas, ear and eyelids and into hair
How are teeth classified
Dental formula
From front to back - incisor, canine, premolar and molar
Typically 3,1,4,3
