BIOL241: Biodiversity of Terrestrial Organisms - Practice Flashcards

A comprehensive set of 250 practice flashcards testing key vocabulary across plant and animal evolutionary biology, terrestrial adaptations, anatomy, physiology, ecology, and conservation.

Biodiversity

Contraction of 'biological diversity'; the variety of life on Earth across all forms and hierarchical levels, including genes, individuals, species, communities, and ecosystems.

Ecosystem Services

Benefits that people derive from natural ecosystems, estimated to be worth trillions of dollars—approximately double the world's GDP.

Indigenous Knowledge (IK)

A cumulative body of place-based knowledges, practices, and beliefs accumulated and transmitted across generations within specific cultural contexts through direct experiential interaction with ecosystems.

Traditional Ecological Knowledge (TEK)

A subset of Indigenous Knowledge specifically pertaining to ecological relationships, environmental processes, and species dynamics.

IPBES

Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services; assesses the state of biodiversity and nature's contributions to people globally.

Cardinale et al. (2012) Framework

A conceptual model illustrating how global change impacts biodiversity, which alters ecosystem functions, affecting ecosystem services and human well-being, driving socio-ecological feedbacks.

Nature's Contributions to People (NCP)

An IPBES reporting framework encompassing 18 reporting categories across regulation of environmental processes, materials and assistance, and non-material contributions.

Maintenance of Options

NCP category 18; the capacity of nature to keep options open for future generations, indexed by species survival probability and phylogenetic diversity.

Modern Extinction Rate

The current rate of species extinction, which is approximately $1{,}000$ times higher than background rates before human domination.

Australian Mammal Endemism

The state of Australian mammal fauna where $86\%$ of the $315$ native terrestrial species are found nowhere else on Earth.

Australian Mammal Threat Level

The proportion of Australian native mammals classified as extinct or threatened, currently exceeding $30\%$.

Haines Orange Mangrove

One of the world's rarest mangrove species discovered by citizen scientist Hidetoshi Kudo on the outskirts of Cairns CBD, far north Queensland in 2016.

COP-15 Global Biodiversity Framework 2030 Milestones

A suite of 21 targets proposed for 2030, including protecting at least $30\%$ of Earth's lands and oceans, halving nutrient losses, reducing pesticides by two-thirds, and eliminating plastic discharge.

Deep Time Event: Origin of Earth

The formation of the Earth approximately $4.6\text{ bya}$ ($4{,}600\text{ mya}$).

Deep Time Event: First Bacterial Evidence

The earliest fossil and geochemical evidence of bacterial life appearing approximately $3.8\text{ bya}$.

Deep Time Event: Evolution of Cyanobacteria

The evolutionary emergence of photosynthetic cyanobacteria approximately $2.7\text{ bya}$.

Deep Time Event: Oxygenation Event

A steep increase in atmospheric oxygen concentration occurring approximately $2.5\text{ bya}$.

Deep Time Event: Eukaryotic Life

The emergence of simple eukaryotic unicellular organisms approximately $1.8\text{ to }2.0\text{ bya}$.

Deep Time Event: Multicellular Eukaryotes

The origin of multicellular eukaryotic organisms in the fossil record approximately $1.5\text{ bya}$.

Cambrian Explosion

A geologically rapid radiation of major animal phyla and complex body plans occurring approximately $541\text{ to }550\text{ mya}$.

Pangea Formation

The tectonic assembly of continents into the supercontinent Pangea $300\text{ to }200\text{ mya}$, which drastically reduced the area of shallow seas.

Mid-Ordovician Dispersed Spores

Microscopic plant spores from mid-Ordovician sediments (Llanvirn, $475\text{ mya}$) in Oman, representing the earliest fossil evidence of bona fide land plants.

Five Terrestrial Colonisation Challenges

The primary selective pressures facing early terrestrial colonisers: UV radiation/DNA damage, gravity/lack of structural support, desiccation, reproduction away from water, and temperature fluctuations.

Pyrimidine Dimers

Molecular lesions formed when adjacent thymine base pairs covalently bond following UV-B photon absorption, inhibiting regular DNA replication.

Photolyase

A DNA repair enzyme that utilizes visible light energy to split UV-induced pyrimidine dimers; absent in placental mammals but present in plants, microbes, and non-mammalian animals.

Flavonoids

Specialised plant secondary metabolites that act as photoprotective organic sunscreens by absorbing damaging UV-B wavelengths.

Relative Density of Air vs Water

Physical condition on land where air is approximately $800$ times less dense than water, necessitating rigid load-bearing structural support.

Lignin

A complex, hydrophobic, non-carbohydrate polymer comprising $25\text{--}40\%$ of the dry mass of woody plants, covalently bound to hemicellulose to provide mechanical rigidity.

Evaporative Water Loss (EWL) Equation

The biophysical formula governing organismal water loss: $\text{EWL} = \frac{A (\text{VP}_o - \text{VP}_a)}{r_s + r_b}$, where $A$ is surface area, $\text{VP}_o$ is organism surface vapour pressure, $\text{VP}_a$ is ambient vapour pressure, $r_s$ is surface resistance, and $r_b$ is boundary layer resistance.

Boundary Layer Resistance ($r_b$)

The resistance to water vapour diffusion provided by a layer of calm, still, moist air immediately adjacent to an organism's surface.

Surface Resistance ($r_s$)

The physiological or structural resistance to water vapour movement across the integument or epidermal cuticle of an organism.

Phyllomedusa Waxy Secretion

A behavioural adaptation in South American hylid frogs wherein lipid wax is actively wiped over the body using limbs to elevate surface resistance ($r_s$) and prevent desiccation.

Weissia controversa

An urban moss capable of complete desiccation tolerance, leaf-rolling when dry, and physiological recovery upon rehydration.

Stoma

A microscopic epidermal pore flanked by two guard cells that regulates gas exchange ($\text{CO}_2$ uptake) and transpirational water loss in terrestrial plants.

Uricotelic Excretion

The excretion of nitrogenous waste primarily as insoluble uric acid or guanine, minimizing water loss in reptiles and birds.

Splash Cups

Cup-shaped reproductive structures on male gametophytes of bryophytes that harness falling raindrops to splash motile sperm toward archegonia.

Cryoprotectant Glucose in Frogs

High concentrations of liver-derived glucose mobilized into body fluids that lower the freezing point inside cells and prevent intracellular ice damage.

Tetrapod

A four-limbed vertebrate clade that evolved from sarcopterygian lobe-finned fishes in the Devonian period.

Sarcopterygii

The class of lobe-finned bony fishes possessing fleshy, paired, lobed fins supported by internal skeletal elements homologous to tetrapod limb bones.

Zygapophyses

Interlocking articular processes on adjacent vertebral neural arches that resist torsional and sagging forces induced by gravity on land.

Labyrinthodont Dentition

Primitive tooth morphology characterized by deeply folded enamel and dentine layers, found in early tetrapods and lobe-finned fishes.

Eusthenopteron

A Late Devonian sarcopterygian fish ($\sim 385\text{ mya}$) displaying internal nostrils (choanae) and an internal fin bone pattern homologous to the tetrapod limb.

Panderichthys

A Devonian transitional fish lacking dorsal and anal fins, possessing dorsoventrally flattened skulls with dorsal eyes and breathing spiracles.

Tiktaalik

A Devonian transitional fossil ($\sim 375\text{ mya}$) exhibiting fish traits (scales, fins) alongside tetrapod traits (mobile neck, flat skull, ribs, primitive wrist joint).

Acanthostega

An early aquatic tetrapod possessing fully formed, polydactylous limbs with 8 digits, but retaining internal gills and a fish-like caudal fin.

Ichthyostega

An early tetrapod with robust overlapping ribs to prevent lung collapse, strong forelimbs for locomotion, and 7 digits on each hind limb.

Hynerpeton

A Devonian tetrapod showing robust weight-bearing pectoral girdles and complete loss of internal gill structures.

Tetrapod Limb Skeletal Evolution

The progressive transition recorded in fossils between $385\text{ and }360\text{ mya}$ showing the evolution of the humerus, radius, ulna, and digits from fleshy-finned sarcopterygians.

Class Amphibia

A class of ectothermic, non-amniote tetrapods with moist, highly permeable skin used in respiration, a 3-chambered heart, and a complex aquatic-to-terrestrial life cycle.

Order Gymnophiona

The amphibian order comprising caecilians; limbless, fossorial forms with annuli, heavily ossified burrowing skulls, and sensory tentacular organs.

Annuli

Dermal circumferential grooves encircling the body of caecilians, which facilitate peristaltic burrowing through soil.

Dermatotrophy

A form of parental care in caecilians where hatched young consume lipid- and protein-rich outer layers of maternal epidermal skin.

Order Caudata

The amphibian order of salamanders and newts, characterized by a long tail, equal-length limbs, and ancestral lateral-undulatory locomotion.

Paedomorphosis

The evolutionary retention of juvenile or larval traits (such as external gills and aquatic habits) into sexually mature adult stages.

Autotomy (Caudata)

The voluntary shedding of the tail to distract predators, followed by subsequent tissue and skeletal regeneration.

Order Anura

The amphibian order of frogs and toads; tailless as adults, with an elongated pelvic girdle and modified hindlimbs specialized for saltation.

Saltatorial Locomotion

Jumping or hopping locomotion powered by simultaneous extension of elongated hindlimbs and structural stabilization via the urostyle.

Buccal Pumping

A positive-pressure respiratory mechanism where air is drawn into the mouth cavity through nostrils, then pushed into lungs by raising the floor of the buccal cavity.

Amplexus

The copulatory embrace of frogs wherein the male grasps the female to position his cloaca near hers as eggs are released for external fertilisation.

Gastric-Brooding Frog

Extinct Australian myobatrachid frogs (genus Rheobatrachus) whose females incubated fertilized eggs and developing young inside their stomachs.

Anuran Metamorphosis

The thyroid-hormone-driven transformation from an aquatic, herbivorous, gill-bearing tadpole to a carnivorous, lung-bearing adult frog.

Aestivation (Frogs)

A state of prolonged metabolic dormancy and torpor during dry, hot periods, often spent underground enclosed in a protective shed-skin cocoon.

Neobatrachia

The advanced suborder comprising 17 families and over $5{,}000$ species ($\sim 96\%$ of all modern frog diversity).

Family Hylidae

Tree frogs, characterized by adhesive cartilage discs on the tips of toes and fingers, binocular vision, and predominantly arboreal or semi-aquatic habits.

Family Bufonidae

True toads, characterized by thick warty skin containing granular glands, well-developed parotoid glands, and the absence of teeth.

Bufotoxins

Cardiotoxic and neurotoxic secretions synthesized and released by the parotoid glands of bufonid toads to deter predators.

Family Dendrobatidae

Poison dart frogs of Central and South America; diurnal anurans featuring vibrant aposematic coloration and defensive alkaloid skin toxins.

Chytridiomycosis

A lethal infectious disease of amphibian keratinised epidermal tissues caused by the fungal pathogens Batrachochytrium dendrobatidis ($Bd$) and Batrachochytrium salamandrivorans ($Bsal$).

Clade Amniota

A monophyletic clade of tetrapods (mammals, reptiles, and birds) defined by the evolution of the amniotic egg, internal fertilization, and a waterproof keratinized skin.

Amniotic (Cleidoic) Egg

A self-contained egg enclosed by a leathery or calcareous shell and four extraembryonic membranes, freeing vertebrate reproduction from standing water.

Amnion

The innermost extraembryonic membrane enclosing the fluid-filled amniotic cavity, protecting the embryo from mechanical shocks and adhesion.

Chorion

The outermost vascularized extraembryonic membrane that lines the shell and mediates respiratory gas exchange ($\text{O}_2$ and $\text{CO}_2$).

Allantois

The extraembryonic membrane sac that stores insoluble metabolic nitrogenous wastes (uric acid) and functions in embryonic gas exchange.

Yolk Sac

The ancestral vertebrate extraembryonic membrane that encloses the nutrient-rich yolk to nourish the developing embryo.

Temporal Fenestration

Openings in the temporal region of the vertebrate skull behind the orbit that provide attachment margins for jaw adductor musculature.

Anapsid Skull

A primitive skull morphology lacking temporal openings behind the orbit; characteristic of ancestral parareptiles and historically assigned to turtles.

Synapsid Skull

A skull morphology possessing a single lateral temporal fenestra bounded by the postorbital and squamosal bones; characteristic of mammals and stem mammals.

Diapsid Skull

A skull morphology possessing two temporal fenestrae (dorsal and lateral) behind the orbit; characteristic of sauropsids including lepidosaurs and archosaurs.

Synapsida

The amniote lineage leading to mammals, characterized ancestrally by good olfaction, secondary nocturnality, and a single temporal fenestra.

Sauropsida

The amniote lineage encompassing reptiles and birds, characterized ancestrally by excellent color vision, diurnal activity, and diapsid or derived anapsid skulls.

Aspiration Pump

A negative-pressure lung ventilation mechanism wherein contraction of thoracic or abdominal muscles expands the thoracic cavity to draw air in.

Secondary Bony Palate

A horizontal osseous shelf separating the oral cavity from nasal passages, enabling simultaneous feeding and respiration.

Double-Circuit Circulation

A cardiovascular plan featuring distinct pulmonary (heart-lung) and systemic (heart-body) circuits to accommodate high terrestrial systemic pressures.

Ectothermy

A physiological condition where internal body temperature is predominantly determined and modulated by heat absorbed from the external environment.

Order Testudines

The reptilian order of turtles and tortoises, distinguished by a body encased in a bony shell with limb girdles positioned inside the ribs.

Carapace

The dorsal vaulted portion of the turtle shell formed by the fusion of dermal bones, expanded vertebrae, and flattened ribs.

Plastron

The flat ventral portion of the turtle shell composed of fused dermal bones derived from gastralia and the clavicles.

Ossification Centres of Turtle Shell

The 59 discrete developmental ossification centres from which the composite turtle bony shell grows and fuses.

Cloacal Respiration (Turtles)

Aquatic accessory gas exchange occurring in vascularized cloacal bursae lined with branching, gill-like papillae in species such as Rheodytes leukops.

Fitzroy River Turtle

Rheodytes leukops; an Australian side-necked freshwater turtle renowned for deriving the majority of its resting oxygen from water pumped across vascularized cloacal bursae.

Temperature-Dependent Sex Determination (TSD)

A mechanism in turtles and crocodilians where incubation temperatures during the middle third of embryonic development determine offspring sex.

Suborder Cryptodira

Hidden-necked turtles; retract the head and neck into the shell along a vertical S-plane, featuring a trochlear process on the anterior otic capsule.

Suborder Pleurodira

Side-necked turtles; fold the neck horizontally sideways against the body, featuring a pelvic girdle fused to the shell and a trochlear process on the pterygoid bone.

Processus Trochlearis Oticum

The pulley-like skeletal structure on the otic capsule around which the jaw adductor tendon bends in cryptodiran turtles.

Processus Trochlearis Pterygoidei

The lateral pterygoid pulley-like process over which the jaw adductor tendon bends in pleurodiran turtles.

Order Crocodilia

An archosaurian reptile order possessing thecodont teeth, a secondary bony palate, a complete 4-chambered heart, and a muscular gizzard.

Thecodont Dentition

Dentition wherein teeth are firmly set into deep sockets (alveoli) within the jaw bones, characteristic of archosaurs including crocodilians and mammals.

Foramen of Panizza

A vascular aperture connecting the bases of the left and right systemic aortae outside the crocodilian heart, facilitating intracardiac shunts.

Cog-Tooth Valve

An active muscular valve in the pulmonary outflow tract of crocodilians that contracts during prolonged dives to redirect deoxygenated blood away from lungs.

Crocodilian Heart Shunt

The physiological redirection of right ventricular blood across the left aorta into systemic circulation during diving, bypassing non-ventilating lungs.