APS122 Biodiversity Flashcards
DEFINITION: Biodiversity
The variability of living organisms from all sources including, but not limited to, terrestrial, marine and other aquatic ecosystems
3 Elements of Biodiversity
- Ecological: Biomes, ecosystems, niches, habitats
- Genetic: Populations, individuals, chromosomes
- Organisms: Kingdoms, phyla, classes, populations
Paleotological Evidence for inferring Evolutionary Relationships
- Appearance in the fossil record
- During the Cambrian explosion there was massive diversification but relationships can only be inferred due to incomplete record
Evolutionary Relationships for inferring evolutionary relationships
- Shared, derived homologous structures
- This is limited by convergent evolution
Developmental Similarity for inferring evolutionary relationships
- Patterns of cell division and embryonic stages
Molecular similarity for inferring evolutionary relationships
- Relates to similarity of DNA, RNA and proteins
- Most useful
Problems with traditional trees of life
- Mostly based on anatomical and developmental similarities
- Lots of organisms missing
- Biased towards animal kingdom
- Man is always on top suggesting progression from lower organisms
Difference between archaea and bacteria
Cell membrane composition
Bacteria: Peptidoglycan inside
Archaea: Ether Lipids inside
Direct Use Values
- Direct use of biological resources in consumption or production
Eg. wood, food, medicine - Concerns marketable commodities
- Can be exploitive
Indirect Use Values
- Services that support human life nut are not traded on markets
Eg. Pollination, O2 production, water management - Ecosystem services are processes by which natural ecosystems and the species fulfil us
DEFINITION: Non use Biodiversity
The benefits we gain from leaving biodiversity alone
DEFINITION: Option Value
Potential use/ non use in the future
DEFINITION: Bequest Value
Passing resources to future generations
DEFINITION: Existence Value
Value to people irrespective of uses now or in the future
DEFINITION: Intrinsic Value
Value independent of human dimension they have a right to exist
Tight Junctions
Found in epithelium cells
- continuous belts that seal layers of epithelium
- common in the intestines
- a layer of cells that covers/ lines an external surface
Desmosomes
Found in epithelium cells
- Anchoring Junctions that form keratin
- They hold cells together at one spot
- Often in the intestines
Gap Junctions
Epithelium cells
- Communicating junctions between two adjacent cells
- ie in the heart
Early embryonic development
- Cell keeps cleavaging forming a blastula
- Hollow centre called blastocoel forms
- Blastula invaginates and folds in during gastrulation
- Gastrula formed with 3 layer: blastocoel, Endoderm, Ectoderm and body axis
- Mesoderm eventually forms within the blastocoel
- The opening becomes the digestive cavity which is called Archenteron, the opening to this is the blastopore
Hox Genes
Genes that regulate development in animals number present correlates with the complexity of a body plan.
Variation in the location of where hot genes are expressed in a developing embryo determines the basis of diversity of animal body plans
Origin of all animals
- All monophyletic with a single colonial heterotroph common ancestor the Choanoflagellate
Choanoflagellate Structures
- Single flagella with a microvillae collar used for feeding
- Similar structure to a singular cilia of primitive animals
- Similar Mitochondrial structures
- Similar DNA
Gastrulation
First separation of phylogenic groups
- Results in at least two tissue layers, endoderm and ectoderm
- Separates the Parazoa (sponges)
- Allowed cell specialisation and organ development
Second Separation of phylogenetic groups Animals
- Separates Radiata and Bilatera
DEFINITION: Radiata
- Oral/ Aboral sides
- Radical Symmetry
- Diploblastic
- No brain but simple nerve network
- Contractile bundles of microtubules act like muscles
eg jelly fish
DEFINITION: Bilateria
- Anteria/ Posteria and Dorsal/ Ventral
- Tripoblastic
- Leads to cephalisation and active lift styles
Eg Lobster
Third Separation of phylogenetic groups Animals
- Separates the protostomes and deuterostomes
- Development of the body cavity known as the Coelom
- Allows protection, stores organs, allows growth and movement
DEFINITION: Protostomes
- Spiral Cleavage
- Determinate
- Coelum formed from splitting of solid mass
- Mouth develops first
DEFINITION: Deuterostomes
- Radial Cleavage
- Indeterminate
- Coelum formed from archenteron folding
- Anus formed first
Fourth Separation of phylogenetic groups Animals
Separates the Lophotrochozoa from Ecdysozoans
DEFINITION: Lophotrochozoa
Have a crown of cilia (lophophore) on their trochophore larva
DEFINITION: Ecdysozoans
Shed their exoskeletons (ecdysis)
Non elastic exoskeleton
Allows growth and a transition from larvae to adulthood
Parazoas
- Asymmetrical, no body plan
- No Gastrulation
- No True tissue, muscle, nervous system or organs
- Some specialised cells
- Sessile
- Eg. Sponges
DEFINITION: Porocytes
Sponge structures
- Where water passes into the sponge
DEFINITION: Flagellum in Sponges
Move the water around the sponge
DEFINITION: Choanocytes
Specialist feeding cells that line the sponge
DEFINITION: Amoebocyte
Collect the food from choanocyte and distribute it, also secretes Ca2+ and silica spiracles for rigidity of cytoskeleton
DEFINITION: Cnidocytes
Located on tentacles and are used for defence and capture of prey
Contain nematocysts which are organelles that inject venom
Types of Cnidocytes
- Anthozoans: anemones, corals only go through polyp stage, all sessile
- Scyphozoans: True jelly fish, dominated by medusa form, more developed nervous system
- Cubozoans: Box jelly fish, cuboid umbrella heads rather than domed, developed nervous system
- Hydrazoans: Some medusi & other polyps, often in colonies
3 Types of Lophotrochozoas
- Flatworms
- Segmented Worm s
- Molluscs
Flatworms
- Phylum Platyhelminthes
- Simple body plan
- Lack of gas exchange & circulatory organs
- Mesoderm with organs, organ systems
- Simple brain & sensory/ motor development
3 Main Types of Flat Worm
- Free Living Marine Worm
- Parasitic Flukes
- Parasitic Tapeworms
Free Living marine worms
- Predators/ Scavengers
- Blind gastrovascular cavity with complex folding
- Ganglia & Eye spots
- Sexually reproduce as hermaphrodites & asexually
Parasitic Flukes
- Primary host is usually vertebrate (human)
- Secondary host is usually invertebrate (snail)
- Multiple life stages, some asexual and others sexual
- Causes schistosome in humans
Parasitic tapeworm
- Head (scolex) with hooks for attachment inside the hosts guts
- Sacks of eggs (proglottids) break off and are transferred to other bodies via faeces
- Self fertilising or hermaphrodite
- No sensory organs
Segmented Worms
- Phylum Annelida
- Has little rings
- Body linear and segmented
- Circular and longitudinal muscles
- Digestive tract has specialised regions
- Simple brain
Three Main Types of Segmented worm
Earthworms: Terrestrial segmented worms, important for soil formation, aeration & releasing nutrients
Polychaetes: Marine segmented worm, developed head and feet
Leeches: Specialised blood sucking parasites, dorsally flattened, segmented
Important evolutionary features of segmented worms
- Well developed body cavity: hydrostatic skeleton, space and cushion for organs
- Segmentation: Allows specialisation of body regions
Molluscs
- Not segmented
- Diverse, but all share same body plan
- Have a foot which is a muscular pad for locomotion
- Visceral Mass which is the flesh contain organs
- Mantle is the tissue covering the visceral mass and secretes shell if used
- Radula is located in the mouth for scraping food
Gastropods
Eg. Snails, Slugs, limpets
- all similar to the basic body plan
- In some snails, mantle cavity acts as lungs so they can inhabit terrestrial environments
- Active lifestyle so have sense organs in heads
Bivalves
Eg. Oysters, mussels, clams
- Shell in two halves, body and foot compressed inside protected
- Gills adapted for filter feeding
- Head and Radula lost
- Sedentary lifestyle
Cephalopods
Eg. Squid, Octopus
- Beak like jaws
- Foot modified into muscular siphon and tentacles
- Mantle: propulsive bellows
- Nautilus only one shell
- Highly active predatory lifestyle
- Closed circulatory system with 3 hearts sometimes
- Efficient eyes, lens moves to and from the retina
- Chromatophores for signalling and camouflage
- Well developed brain, capable of memory and learning
2 Types of Ecdysozoans
- Round worms
2. Arthropods
Round worms
- Phylum Nematoda
- Cuticle is shed
- Unsegmented, tapers at the tail
- Complete digestive tract with anus
- Moves by thrashing tail using longitudinal muscles, no directional movement
- Possibly most abundant multicellular animal
- Can be free living or parasitic
Arthropods
- Phylum Arthropoda
- Body covered in jointed exoskeleton (cuticle)
- Cuticle is strong & waterproof, made of chitin and protein enabling exploitation of land
- Segments fused in groups forming regions
- Appendages specialised ( for feeding, sensory, locomotion)
- Well developed brain and sensory organs
4 Types of Arthropod
- Chelicerates
- Crustaceans
- Centipede, Millipede
- Insects, Hexapods
Chelicerates
- Spiders, horseshoe crabs , ticks
- Have cephalothorax and abdomen
- Cephalothorax lacks antennae
- First appendages are chelicerae for feeding, then pelipalps for sensing or feeding, and four pairs of legs
- Abdomen usually lacks legs
Crustaceans
- Lobsters, Crabs
- Two pairs of antennae
- 3+ pairs of mouth part appendages
- Thorax has legs for walking
- Abdominal segments have swimming appendages
Centipedes & Millipedes
- Have a head and the rest of the body is highly segmented
- Paired segments are fused in millipedes so there are two less legs per segment
Insects & Hexapods
- 3 Specialised regions (Head, thorax, abdomen)
- One pair of antennae
- Unbranched appendages
- Efficient gas exchange through tracheal system, leads to every cell in the body
- spiracles regulate air flow
- Sophisticated sensory organs
- Well developed brain for complex behaviour
- On for two pairs of wings
Potential Origins of flying insects
- Gliding from vegetation to ground
- Gills in aquatic ancestors
- Swimming fins from aquatic ancestor
- Het absorption
How was flight in insects made possible
- Abundance of muscle tissue
- Light weight jointed skeleton
- Small body size
- Efficient gas/ nutrient exchange
- Highly developed nervous/ sensory system for navigation
Echinoderms
- Phylum Echinodermata
- Adults almost always radially symmetrical but larvae bilateral
- Often radiate from central disk with 5 arms
- Endoskeleton made of calcareous plates (become spike)
-Water vascular system compromises of canals and tube feet that function in locomotion, feeding & gas exchange - The opening fo this is off centre to anus so not true racial symmetry
- No brain, sessile, slow moving
Eg. starfish
DEFINITION: Notochord
Notochord is a long flexible rod that lies between digestive tract and nerve cord in embryo, for skeletal support
DEFINITION: Dorsal hollow nerve chord
Dorsal hollow nerve chord is a rolled up plate of dorsal ectoderm
DEFINITION: Pharyngeal Slits
Pharyngeal Slits in the throat region of the digestive tract which allow water to pass through
DEFINITION: Muscular post anal tail
An extension beyond the anus
DEFINITION: Urochordates
- Tunicates or Sea Squirts
- Adult form is sessile
- U Shaped filter feeder
- The larvae looks more like a chordate, free living
DEFINITION: Cephalochordates
- Lancelets, Branchiostoma
- Have all four chordate features
- Swim with side to side undulations similar to fish
- No real head, brain, sensory organs, heart, jaw or fins
- Mouth surrounded by cirri that strain and direct food to the mouth, food is collected in the pharyngeal slits
DEFINITION: Vertebrates
- Vertebral column forms main axis of the body
- Well developed brain & sensory organs in the head
- Closed circulatory system with ventral chambered heart
Jawless Fish
- Lampreys, Hag fish
- Scavengers
- Only vertebrates isotonic with sea water
- Other vertebrates must maintain osmotic balance so ancestor lived in fresh water
- Produce slime when threatened so become slippery
Jawed fish
- Have jaws
- 2 appendages
- Evolved with hinges that move up and down unlike invertebrates
Cartilaginous Fish
- Sharks and Rays
- Flexible endoskeleton of cartilage, which is a derived trait most other vertebrates have cartilage replaced by bone
- Many covered in small tooth like placoid scales
- Acute senses: vision, electroreceptive, pressure detecters
- Heterocercal tail and wing like pectoral fins provide lift because body is negatively buoyant
Bony Fish
- Endoskeleton of calcium phosphate
- Skin is flattened by bony scales
- Lateral line system
- Gas-sac organ for O2 reservoir, buoyancy
- Some have electrostatic receptors
- Water moves across operculum and pharyngeal muscles
Lobed- Finned Fish
- Muscular pectoral & pelvic fins supported by extensions of the skeleton
- Large bottom dwellers that may have walked on the sea bed
- Coelocanth are the only living species
Lung Fish
- Have lungs and nostrils
- Breath air
- Live in stagnant ponds and swamps
Ray-Finned Fish
- Fine scales increases their mobility
- Homocercal tail allows better manoeuvrability
- Efficient jaw, premaxilla and maxilla now free and articulated
- Swim bladder means they have good buoyancy so fins aren’t needed for lift so were used as brakes and a rudder instead
Eg. Puffer fish, oarfish
Why did animals move to the land?
Escape predators and more prey on shore
Reduced habitat for fish due to cyclic weather and drying conditions
Who were the first tetrapods?
- Would’ve been fish from shallow swamps
- Pre adapted for life on land with heavy skeletal structure of fins which can support body, lungs with internal nostrils to breathe air
Challenges to living on the land
- UV light
- Physical support
- Sensory modification
- Desiccation of sperm and eggs
- Variable temperature
- Water loss
Amphibians features
- Dominated the Carboniferous period
- Had lungs and epidermis
- Epidermis had chromatophores to absorb UV, Keratin reduced water loss, Mucous reduced water loss, Blood capillaries allowed gas exchange
- Skeleton and paired appendages
Limitations to Amphibians features
- Blood mixes in the middle heart chamber
- Dehydrate quickly through skin and waste excretion
- Require water for reproduction
- Eggs develop into tadpoles
Newts and Salamanders features
- Aquatic and terrestrial
- Long trunk, tail, well developed limbs
- Some are paedomorphic (sexual maturity reached in larval stage)
Eg. Axolotl, Salamander
Frogs and Toads features
- Highly diverse in the topics
- Better adapted for terrestrial life
- Short trunk and lost tail
- Ribs fused to vertebrae
- Powerful hind legs for jumping
Caecilians features
- Subterranean, tropical, live underground
- Most blind but some can distinguish light and dark
- Tentacles probably olfactory (for smell)
- Worm like through convergent evolution
Amniotic Egg
- A self contained waterproof chamber for development, eliminates the larval stage
- Contains four membrane layers for protection until birth: Amnion, Allantois, Chorion, Yolk Sac
Reptile features
- Paraphyletic (multiple lineages)
- Heavy ossified skeleton, strong joints and claws
- Skin covered in keratinised scales prevents desiccation
- Internal fertilisation, eggs laid on land
- Ectothermal
- Efficient predators
Turtles, Turpins, tortoises features
- Teeth replaced by sharp horny plates
- Bony dermal plates fused to form caprice & plastrons
- Retractable limbs
- Includes marine, freshwater and terrestrial forms
Lizards & Snakes features
- Lizards have similar form to newts/ salamanders
- Snakes lost limbs and body elongated
- Eyelids lost, spectacle clear for burrowing
- Jaws extremely flexible to swallow large prey
Alligators & Crocodiles features
- Adapted for life in water: broad flattened tail, eye ear and nose openings on top of head
- Most closely related to dinosaurs
Tuatara
- Two species only found in NZ
- Very slow growing
Bird features
- Defined by presence of feathers
- Reptile features like scaly legs and amniote eggs retained
- Hollow bones with cross section and hollow bones to decrease weight
- No teeth, food ground up
- Light weight keratin bill
- Large pectoral muscles anchored to keel
- Wings have aerofoil shape for efficient lift
- Endotherms and use feathers/ fat for insulation
- Four chambered heart and large brain
Ratite features
- Lack a keel but have a wide sternum, lost flight
- Vestigal wings, powerful legs
- Not monophyletic, 4 evolved separately
- Ostrich, Kiwi
Carinates
Perching birds such as owls, penguins, sparrows
Mammal features
- Massive radiation at the end of the mesozoic Era after continents broke apart an dinosaurs went extinct
- Endothermic vertebrates
- Possess hair made of keratin for insulation
- 4 chambered heart
- Limbs carried beneath the body
- Large brain
- Skin glands including mammy glands
- Heterodont teeth specialised for many functions
Monotreme Features
- Reptilian characteristics: egg laying
- Mammalian characteristics: Hair, mammary glands
- Two genera Platypus and Echidna
- Only found in Australia and New Guinea
Marsupial Features
- Egg contains yolk and shell membrane
- Embryo nourished mostly by yolk then placenta
- Short gestation time, young altricial so dependent on mum for 1 month
- Young have strong forelimbs and claws, climb into marsupium
Placental Mammal Features
- Complete development in the uterus
- Phylogenetic relationships between orders are difficult to resolve as they radiated quickly
- 4 major lineages according to molecular clocks
Afrotheria
- Clade of mammals
- Eg elephants, manatees
Xenarthra
- Mammals
- Sloths, anteaters, armadillos
- Have reduced/ no teeth
Laurasiatheria
- Mammals
- Includes: carnivores, insectivores, Cetaceans, Artiodactyls, Perissodactyls
DEFINITION: Cetaceans
Mammals adapted for sea life
Eg Whales, dolphins
DEFINITION: Artiodactyls
Even toed ungulate mammals
Bunodont or selenodont teeth
Elborate ruminant stomach
Eg. sheep, pigs, deer
DEFINITION: Perissodactyls
Odd toed ungulate mammals
Iophodont grinding molars and incisors for cropping
Simple stomach
Eg. Horses, Rhinos
Boreoeutheria
Mammals which include the lagomorphs, rodents and primates
DEFINITION: Lagomorphs
Rabbits and Hares, 2 pairs of rootless incisors and hypsodont molars
What are the two lineages of Prosimians
(Pre monkeys)
- Lemur Lineage
- Tarsier Lineage
Both mostly nocturnal
Anthropoid Features
- Monophyletic
- Reduced nose, sense of smell
- Primary communication vision, developed colour vision
- Therefore observe social cues, elaborate social organisation
- Tactile senses with developed digits and ridges on tips for grip
- Large brain
What are the four types of Homo
Homo Habilis
Homo Erectus
Homo Sapien Neanerthalis
Homo Sapien Sapiens
DEFINITION: Embryophta
A subgroup of land plants, everything else is algae
Plant evolution in the Devonian Period
Evolution of seeds, widespread radiation, fossils all around the world
Plant evolution in the Silurian Period
Plant colonisation of the land
Plant evolution in the Ordovician Period
Earliest evidence of fully resistant spores, photosynthetic algal mats
Plant evolution in the Cambrian Period
Intermediate spores seen, molecular clock indication of land plant evolution
Plant life land before land plants
- Pond Scum, free living organisms in fresh water bodies
- Microbial mats, on damp surfaces periodically inundated with water
- Endoliths beneath or within rocks
- Biological soil crusts on rudimentary soil, dead matter from the sea
Main issues for plants moving onto land
- Physical support
- Lack of water
- Lack of water to filter light
Two ways for plants to evolve past land issues
AVOIDANCE Evolve support & structures eg cell walls
TOLERANCE Accept being a mound of cells
