LEC.142 Zoology Flashcards
What is the Linnaean system of classification?
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
What do homologous and analogous mean with examples?
Homologous: pentadactyl limbs e.g. humans/cats/whales/bats
Analagous: streamline appendages e.g. sharks/penguins/dolphins
What is the difference between homologous and analogous organisms?
Homologous organisms have common ancestry whilst analogous organisms have convergent evolution
What is the difference between primitive and derived characters?
Primitive: Comparing among mammal groups
Derived: Comparing mammals with other vertebrate groups
What is used to find evolutionary relationships with an example?
Fossil record, the Tiktaalik (first complete transitional specimen between fish and land-dwelling tetrapods)
What are 2 challenges of using fossil records to find evolutionary relationships?
- Incomplete records for invertebrates (no bones to fossilise)
- Convergent evolution obscures relationships
Which other 2 strategies can be used to find evolutionary relationships instead of fossil records?
- Embryology
- Genetic similarity (molecular analyses, increasingly used)
What is the phenetic system of classification?
Based on phenotypic similarity (unreliable)
What are the similarities and differences between the classic and cladistic systems of classification?
Similarity: Both reflect evolutionary relationships
Difference: Classic is for both primitive/derived characters, cladistic is only derived
What are the differences between a cladogram, phylogram, and dendogram?
Cladogram: Node position indicates relative time but branch lengths are arbitrary
Phylogram: Branch lengths represent change over time
Dendogram: Nodes are associated with specific geological time
What is the difference between monophyletic, paraphyletic, and polyphyletic phylogenetic trees?
Monophyletic: Ancestor and all descendants
Paraphyletic: Ancestor but not all descendants
Polyphyletic: Missing ancestors (algae)
What is parsimony?
Selecting the phylogenetic tree with less evolutionary steps
What are the 3 ways of adding time to phylogenetic trees?
- Radiometric dating (compares amount of radioactive isotopes with amount of decay products)
- Stratigraphy
- Molecular clocks (amount of genetic divergence)
What are the 6 kingdoms and 3 domains?
Kingdoms: Eubacteria, archaea, protista, plantae, fungi, animalia
Domains: Bacteria, archaea, eukarya
What does heterotrophic mean (animalia)?
Can’t make own food (unlike plants)
What are 2 ways of differentiating in terms of body plans?
- Body symmetry (asymmetric/radial/bilateral)
- Body cavities (coelomates/acoelomates/pseudocoelomates)
What does coelomate, acoelomate, and pseudocoelomate mean?
Coelomate: Internal cavity with organs surrounded by mesoderm
Acoelomate: No internal cavity
Pseudocoelomate: Internal cavity with organs not surrounded by mesoderm
What are the 2 types of coelomates?
- Protostomes
- Deuterostomes
What are the differences between protostomes and deuterostomes?
Protostomes: Mouth develops from blastopore, 2 layers of cells in embryo aren’t aligned
Deuterostomes: Anus develops from blastopore, 2 layers of cells in embryo are aligned
What are 6 features of phylum Porifera “pore-bearing”?
- Aquatic
- Sessile with free-swimming larvae
- Asymmetric
- No true tissues/organs
- Flagellated collar cells
- Mostly hermaphrodite (have both male/female sex organs)
What are 5 features of phylum Cnidaria “stinging”?
- Aquatic
- Radial symmetry
- 2 body forms (sessile polyps + mobile medusae)
- Acoelomates
- Cnidocytes (stinging cells)
What are the 3 types of Cnidarians (stinging)?
- Hydra
- Jellyfish
- Sea anemones + coral
What are 4 features of phylum Platyhelminthes “flat worms”?
- Free-living aquatic/parasitic
- Bilateral symmetry
- Acoelomates with parenchyma
- Waste excreted through skin
What are the 4 classes of Platyhelminthes?
- Free-living flatworms
- Flukes
- Tapeworms
- Parasitic flatworms
What are 4 features of parasites?
- Reduced sense organs
- Attachment organs
- Anaerobic respiration
- Asexual reproduction
What are 6 features of phylum Mollusca “soft”?
- Bilateral symmetry
- Coelomates
- Mantle membrane secretes shell
- Muscular foot for locomotion
- Head generally well-developed
- Radula for feeding
What are the 4 classes of Mollusca?
- Chitons
- Gastropods (snails/slugs)
- Cephalopods (ocotpi/squids)
- Bivalves
What are 4 features of phylum Annelida “ringed”?
- Bilateral symmetry
- Coelomates
- Chaetae (bristles)
- Metameric segmentation
What are the 2 classes of Annelida (new)?
- Errantia (marine predators, “travelling” - crawl/burrow on seafloor)
- Sedentaria (earthworms/leeches/marine sedentary worms)
What are 4 features of phylum Nematoda “threadlike” (roundworms)?
- Bilateral symmetry
- Pseudocoelomates
- Cuticle helps maintain high pressure inside (hydrostatic skeleton)
- Muscles not antagonistic (twitch side to side)
What are the 2 types of Nemadota?
- Free-living (important in soil nutrient cycling)
- Parasites (can cause elephantiasis)
What are C.elegans (Nemadota) an important model for?
Cell/developmental biology as first multicellular organism to have genome sequenced
What are 4 features of phylum Echinodermata “spiny skin” (starfish/urchins etc.)?
- Bilateral symmetry larvae but radial in adults
- Coelomates
- Thin epidermis covering endoskeleton
- Water-vascular system (internal canals + external tube feet)
What are the 5 classes of Echinodermata?
- Crinoidea (sea lillies)
- Asteroidea (starfish)
- Ophiuroidea (brittle stars)
- Echinoidea (urchins)
- Holothuroidea (sea cucumbers)
What are 4 features of phylum Arthropoda “joint + feet”?
- Bilateral symmetry
- Coelomates
- Exoskeleton (chitin/proteins + segregated by epidermis)
- Well-developed respiratory/excretory/blood/sensorial systems
What are the 4 stages in the growing process of phylum Arthropoda?
- Intermoult
- Premoult
- Moult
- Postmoult
What are 3 advantages of the exoskeleton (Arthropoda)?
- Protection
- Reduced water loss
- More efficient locomotion (muscles)
What is the disadvantage of the exoskeleton (Arthropoda)?
Limits growing, gas exchange + movement
What are the 4 different ways gas is exchanged in Arthropoda?
- Through skin (small organisms)
- Gills (aquatic/crustacean)
- Book lungs (scorpions/spiders)
- Trachae (insects/millipedes)
What are 5 features of subphylum Myriapoda “countless number + feet” (millipedes/centipedes)?
- Terrestrial
- Gas exchange by trachae
- 1 pair of antenna
- Many marching legs
- Epicuticle waxy + waterproof
What are 5 features of subphylum Crustacea “crust” (shrimp/crabs)?
- All aquatic except woodlice
- Gas exchange by gills
- 2 pairs of antenna
- 5 pairs of marching + 5 pairs of swimming legs
- Epicuticle lacking waxy waterproof, procuticle with CaCO3
What are the 3 classes of Crustacea?
- Branchiopoda (water flea)
- Maxillopoda (barnacles/copepods)
- Malacostraca (krill/crabs/lobsters/woodlice)
What are 6 features of subphylum Chelicerata “claws/jaws/fangs” (spiders/scorpions/horseshoe crabs)?
- Terrestrial except horseshoe crabs
- Gas exchange by book lungs/trachae/gills
- No antenna
- 4 pairs of marching legs
- Indirect sperm transfer
- Sophisticated mating + parental care behaviours
What are 6 features of subphylum Hexapoda “six feet”?
- 1 pair of antenna
- 3 pairs of legs + 2 pairs of wings
- Internal fertilisation (direct sperm transfer)
- Courtship behaviors
- Sexual dimorphism
- Complex life cycles (complete metamorphosis)
What are 7 reasons why Hexapoda are so successful?
- Great adaptability
- Small body size
- Exoskeleton well adapted to life on land
- Capable of flight
- Well developed sensorial organs
- Fertility
- High diversity of mouthparts allows exploitation of many different resources
What is an example of a social insect behaviour (Hexapoda)?
Honey bee ‘waggle dance’ communicates location of food to other members of the colony
What are 3 ecological services of Hexapoda?
- Pollination
- Pest control
- Nutrient recyling
What are 3 ecological disservices of Hexapoda?
- Crop pests
- Livestock ectoparasites
- Disease vectors
What are 3 features of non-insect Hexapoda?
- 3 pairs of legs + wingless
- No visible mouthparts
- Ametabolous (no metamorphosis)
What are the 2 types of insect in class Insecta and what do these terms mean?
- Hemimetabolous - incomplete metamorphosis
- Holometabolous - complete metamorphosis
Hemimetabolous: What are 4 features of orders Odonata/Ephmeroptera/Plecoptera (dragonflies etc.)?
- Adults have membranous wings
- Aquatic nymphs
- Chewing mouths
- Adults/juveniles occupy same habitat
Hemimetabolous: What are 4 features of order Dermaptera (earwigs)?
- First wing pair short + hard, second pair membranous
- Pincer-like appendages
- Mostly omnivorous
- Males/females have diff. cerci
Hemimetabolous: What are 3 features of order Orthoptera (crickets/grasshoppers/bush crickets)?
- Enlarged back legs for jumping
- Mostly herbivorous
- Females have ovipositor (used to lay eggs)
Hemimetabolous: What are 3 features of orders Phamatodea/Mantodea/Blattodea (stick insects/mantises/cockroaches)?
- First wing pair in adults leathery
- Terrestrial nymphs
- Adults/juveniles have chewing mouths + feed on similar food
Hemimetabolous: What are 2 features of order Hemiptera (treehoppers/cicada/aphids)?
- Piercing-sucking mouths
- Mostly herbivorous
Holometabolous: What are 2 features of order Coleoptera (beetles)?
- First wing pair hard (elytra)
- Diverse lifestyles (carnivorous/scavengers/decomposers etc.)
Holometabolous: What are 2 features of order Lepidoptera (butterflies/moths)?
- Wings with small scales
- Adults nectar feeders, caterpillars herbivorous
Holometabolous: What are 2 features of order Diptera (true flies/mosquitoes)?
- Many diff. lifestyles (carnivorous/parasitoids/pollinators)
- Larvae have diff. niches to adults
Holometabolous: What are 2 features of Hymenoptera (bees/bumblebees/wasps/ants)?
- 2 pairs of membranous wings (ants - most adults wingless)
- Many diff. lifestyles
What are 4 features of Chordates?
- Notochord - stiff, cartilaginous rod that extends along inside of body
- Dorsal, hollow nerve cord - main trunk of CNS
- Postanal tail
- Pharyngeal slits
What are the 2 types of non-vertebrate Chordates?
- Tunicates
- Lancelets
What are the 4 defining features of vertebrates?
- Vertebral column (notochord modified into spine)
- Cranium
- Spinal cord
- Neural crest (group of mobile embryonic cells - give rise to diverse cell types)
What are the 7 major extant groups of vertebrates?
- Agnatha (jawless fish)
- Chondrichthyes (cartilaginous fish)
- Osteichthyes (bony fish)
- Amphibia
- Reptilia
- Aves (birds)
- Mammalia
Vertebrates: What are 2 features and 2 types of group Agnatha (jawless fish)?
- Lack jaws + paired fins
- Elongate, scaleless + slimy
Hagfish and lampreys
Vertebrates: What are 2 features and 2 types of group Chondrichthyes (cartilaginous fish)?
- Cartilaginous skeletons + paired fins
- Claspers in males for internal fertilisation
Sharks/skates/rays and chimaeras
Vertebrates: What are 2 features and 2 types of group Osteichthyes (bony fish)?
- Bony skeleton + paired fins
- Swim bladders
Ray-finned and lobe-finned
Vertebrates: What are 2 features and 3 types of group Amphibia?
- Tetrapods with moist/scaleless skin
- Aquatic larvae + terrestrial adults
Frogs/toads, salamanders, and caecilians
Vertebrates: What are 2 features and 3 types of group Reptilia?
- Tetrapods with scaly skin
- First amniotes (no aquatic stage) - 1 group gave rise to birds, the other mammals
Turtles, lizards/snakes, and crocodilians
Why did flightless birds evolve from flying ancestors?
Enabled by reduced predation risk
What are 4 features of waterbirds and an adaptation of seabirds?
- Webbed/lobed feet
- Dense plumage
- Usually waterproof
- Must breed on land
Seabirds have gland in nose that gets rid of excess salt
What are 3 features of birds of prey?
- Talons/hooks for killing + tearing flesh
- Forward-facing eyes (binocular vision)
- Hunt mammals and other birds
What are 3 features of wading birds (e.g. dunlins)?
- Long legs + probing bill for muddy, wet areas
- Feed on invertebrates
- Adaptive radiation in bill shape so species exploit diff. niches
What is the purpose of song birds’ songs?
Communication signal to attract females
Describe plumage colour in birds
Can provide camouflage and used as sexual signals
Describe breeding in birds
Lay eggs in nests –> incubation –> bi-parental care
Describe chick development in birds (2 types)
- Precocial: downy, can thermoregulate + feed themselves on hatching
- Altricial: naked + blind, can’t thermoregulate or feed themselves
Describe social behaviour in birds
Form social flocks for safety e.g. breed in colonies, roost/forage in groups
Describe migration in birds
Seasonal migration usually north-south, ringing can help to track movements
How were peregrines used as bioindicators during the 1960s and 70s?
Indicated that environment was being poisoned by DDT (insecticide)
What are 6 hypothetical stages of feather evolution?
- Reptilian scale
- Elongation (solar radiation)
- Splitting (elongation + flexibility)
- Fraying + pigmentation (insulation + displays)
- Elongation (flight/balance)
- Secondary splits/barbs/hooks
What are the 4 types of feather?
- Contour (cover body)
- Down (insulate)
- Semiplume/filoplume (structural)
- Flight (calamus, rachis, vane)
What are feathers/beaks/claws made of compared to what mammalian hair/claws/hooves are made of?
Beta keratin compared to alpha keratin in mammals
What are the 8 feather tracts (where feathers are on a bird’s body)?
- Capital (head)
- Spinal
- Ventral (neck/chest)
- Humeral (arm)
- Femoral (leg)
- Crural (tail)
- Alar (wing)
- Caudal (tail)
What are the 3 forms of feather maintenance?
- Preening with oil (waterproof, produced from gland on back)
- Bathing in water/dust (removes parasites)
- Moulting (primaries moult first, then secondaries)
What are 3 reasons for feather moulting?
- Feathers wear out from abrasion/UV
- Removes collected mites/parasites
- Changes plumage (breeding + non-breeding)
What is variation in moult related to?
Flight dependency
What 3 things does active flight require?
- Large wing surfaces
- High energy
- Very efficient O2 transport
What is the equation for wing aspect ratio and what does a low and high value tell us?
(wingspan)^2 / wing area
Low value = short + round wings
High value = long + thin wings
What are the advantages to birds having either short + round wings or long + thin wings
Short + round = rapid take-off, high manoeuvrability
Long + thin = good gliders, high speed
What feature allows birds to fly at low speeds without stalling from turbulence?
Alula/bastard wing (decreases turbulence)
What feature in soaring birds (e.g. eagles/vultures) gives them greater control at low speeds?
Wing tip slots
What are the 4 parts of a bird’s respiratory system?
- Glottis
- Trachea
- Lungs
- Air sacs (act as a pump to pump oxygenated air across gas exchange membrane)
What are 2 ways a bird’s respiratory system is different to a human’s?
- One-way air flow over lungs
- Air pump and gas exchange are separate (thinner exchange surface so higher efficiency to meet high O2 demand of flight)
What are 3 other adaptations birds have for flight?
- Hollow bones (lighter)
- No teeth (lighter head)
- Centre of gravity is in body centre rather than head
What are 5 characteristics of mammals?
- Mammary glands
- Hair
- Neocortes (part of brain - cognition)
- Complex placenta (except marsupials/monotremes)
- Vivipary (give birth to live young, except monotremes)
What did mammals evolve from?
Synapsid reptiles (single opening in skull behind eye)
What are the 3 major groups of mammals?
- Prototheria (monotremes - oviparous, lay eggs)
- Metatheria (marsupials - vivparous but pouch development)
- Eutheria (all placentals, vivparous)
What are 3 features of monotremes/Monotrema (platypuses/echidnas)?
- Oviparous
- One opening = cloaca
- Spur on hindleg (venomous in male platypuses)
What are 3 features of marsupials (wombats)?
- Give birth to poorly developed young
- Young develop in pouch
- Convergent evolution
What are 3 features of rodents/Rodentia (capybaras/mice)?
- 1 pair of continuously growing incisors in each jaw
- Many herbivorous, some omnivorous
- Many model species (lab rats) but also pests
What are 3 features of lagomorphs/Lagomorpha?
- 2 pairs of incisors on upper jaw
- All herbivores
- Double digestion (2 types of faeces produced, 1 reingested)
What are the 2 groups of lagomorphs?
- Hares/rabbits
- Pikas
What are 4 features of primates?
- Distinctive skeletal structure
- Opposable thumbs
- Large brain
- Highly intelligent (advanced cognition)
What are the 4 groups of primates?
- Prosimians
- Monkeys
- Lesser apes
- Greater apes
What are 3 features of insectivores/Eulipotyphyla (shrews/hedgehogs/moles)?
- Ground-dwelling
- Pointed snout
- Insectivorous
What are the 2 groups of bats/Chiroptera and what is an example of a disease that this group is an important vector for?
- Large fruit bats
- Small echolocating bats
Rabies
What is 1 feature of carnivores/Carnivora (cats/dogs/bears/seals)?
Distinctive skull structure + dentition
What are 2 features of ungulates?
- Hoofed mammals
- Mostly herbivorous with specialised digestion
What are the 2 groups of ungulates?
- Perissodactyla (odd-toed) - horses/tapirs/rhinos
- Artiodactyla (even-toed) - pigs/hippos/deer/antelopes/sheep
What are 4 features of cetaceans/Cetacea (whales/dolphins/porpoises)?
- Forelimbs modified to flippers
- Hindlimbs vestigal + not attached
- Aquatic (all oceans but some freshwater)
- Echolocation + electroception
What are the 3 influences on mating systems?
- Anisogamy
- Gestation + lactation
- Diet, habitat, + density
How does anisogamy influence mating systems?
Females produce few eggs (costly), males produce many sperm (cheap) so female breeding success limited by no. young raised (quality), male breeding success limited by no. eggs fertilised (quantity)
How does gestation + lactation influence mating systems?
Females constrained by costly, lengthy development, post-copulation males can move on (no time constraint)
How does diet, habitat, + density influence mating systems?
Carnivores: prey hunted so parental care needed and males should stick around
What are the 2 types of mating?
- Monogamy
- Polygamy (either polygyny - 1 male + many females or polyandry - 1 female + many males)
What are the 3 types of polygyny (1 male, many females)?
- Female defence polygyny (males monopolise females, competition, adaptations for fighting)
- Resource defence polygyny (females can’t be monopolised so males attract females)
- Scramble competition polygyny (no male dominance as females dispersed so males move around)
In what type of species is polyandry more common in, what is an advantage of polyandry, and what does polygynandrous mean?
Litter-bearing species e.g. rodents, less risk of infanticide with paternal uncertainty, polygynandrous = both sexes have multiple partners (e.g. in semelparous mammals - only breed once)
What are the 4 factors that affect group living (social systems)?
- Predation pressure
- Social foraging/hunting
- Thermoregulation
- Breeding constraints
Describe solitary life (social systems)
Good option if territories/resources easily defended, many top predators solitary
Describe semi-sociality (social systems)
Temporary groups formed in certain conditions for protection/reproduction/warmth
Describe sociality (social systems)
‘Fission-fusion’ occurs, direct social interaction but limited cooperation, individuals breed independently
Describe communal breeding (social systems)
Many/all females breed and offspring care is shared, low reproductive skew
Describe cooperative breeding (social systems)
Young/small females remain in group and help but don’t breed, often only 1 female successfully breeds, high reproductive skew
Describe eusociality (social systems)
Non-breeding females are sterile, breeding females (‘queens’) and workers show specialisation