VCE Biology Outcome 2 Practice Flashcards

Vocabulary practice flashcards covering asexual and sexual reproduction, cloning techniques, ecology level organization, structural/physiological/behavioural adaptations, plant xerophyte/halophyte traits, genetic diversity dynamics, and population ecology concepts.

Gametes

Specialised male and female sex cells containing a haploid ($n$) number of chromosomes that fuse during sexual reproduction.

Zygote

A new diploid ($2n$) cell formed by the fusion of male and female haploid gametes.

Hermaphrodite

An organism possessing both male and female reproductive systems that is capable of self-fertilization to produce genetically unique offspring.

Fission

The most common form of asexual reproduction among unicellular organisms, where a single parent cell divides into two or more equal parts.

Budding

A form of asexual reproduction where the division of cytoplasm is unequal and a new individual arises as an outgrowth or bud from the parent.

Fragmentation

A form of asexual reproduction in multicellular organisms where the body breaks into two or more parts, each of which regenerates into a new, complete individual.

Mitospores

Asexual reproductive cells produced through mitosis by organisms such as bacteria, fungi, algae, and plants.

Zygospores

Reproductive spores formed through sexual reproduction.

Sporangium

A structure produced by some fungi that holds a cluster of spores prior to their release by wind or water.

Vegetative propagation

A form of asexual reproduction in plants where new individuals grow from specialised non-reproductive plant tissues when separated from the parent plant.

Rhizome

An underground stem that branches to produce new shoots and roots in vegetative propagation.

Stolon

A stem similar to a rhizome that grows above the ground to produce new shoots and roots.

Parthenogenesis

A form of asexual reproduction in females where an unfertilized egg develops into a complete offspring without fertilization by a male gamete.

Cultivar

The stem section of a desired plant chosen for fruiting, flowering, or aesthetics that is grafted onto a rootstock.

Rootstock

The cut stem of a plant with well-developed roots onto which a cultivar is grafted.

Callus

A mass of undifferentiated cells formed from parent plant fragments placed in a nutrient growth medium during tissue culture.

Embryo splitting

An artificial cloning technique where early-stage embryos created via IVF are physically separated into totipotent cells and implanted into surrogate mothers.

Somatic Cell Nuclear Transfer (SCNT)

A cloning process involving the removal of a nucleus from an unfertilised egg and replacing it with a diploid nucleus from an adult somatic cell.

Enucleated egg

An unfertilised egg cell whose nucleus has been physically removed using a micro-pipette, leaving an intact cytoplasm, cellular machinery, and mitochondria.

Therapeutic cloning

An application of SCNT used to harvest embryonic stem cells for medical treatments rather than creating a cloned individual.

Telomeres

Repeated DNA sequences at the ends of chromosomes that shorten as cells age, contributing to premature aging in clones derived from adult somatic cells.

Population

All members of a single species occupying a defined geographical boundary at a specific time.

Community

Multiple interacting populations of different species occupying the same geographic area.

Ecosystem

All populations in a given geographic area interacting with each other (biotic) and their non-living (abiotic) environment.

Biosphere

All regions of the Earth, from ocean depths to the atmosphere, capable of supporting life.

Interspecific interactions

Ecological relationships or interactions occurring between individuals of different species.

Intraspecific interactions

Ecological relationships or interactions occurring between individuals of the same species.

Autotroph

An organism (producer) that produces organic compounds from inorganic materials using solar or chemical energy.

Heterotroph

An organism (consumer) that obtains organic compounds by consuming other living organisms or dead organic matter.

Detritivore

An organism that ingests dead organic fragments, cast-off parts, and wastes, digesting them internally.

Decomposer

An organism (such as fungi or bacteria) that secretes digestive enzymes externally to break down dead tissues and organic wastes into simple inorganic nutrients.

Trophic level

A specific feeding step or position occupied by an organism within a food chain, food web, or food pyramid.

Primary productivity

The rate at which new organic material is created by producers within an ecosystem.

Habitat

The specific physical location where an organism lives.

Niche

The specific functional role and position of a species within its ecosystem.

Symbiosis

A close ecological relationship between two different species living together, benefiting at least one of the species.

Obligate mutualism

A symbiotic relationship in which both species benefit and are entirely dependent on each other for survival and reproduction.

Facultative mutualism

A symbiotic relationship where both species benefit from interacting but do not strictly depend on each other for survival.

Parasitism

A symbiotic relationship in which one organism (the parasite) feeds or lives on or inside another host organism, usually harming or weakening it.

Commensalism

A symbiotic relationship in which one species benefits while the other species is neither helped nor harmed.

Amensalism

An ecological interaction where one species is inhibited or destroyed while the other species remains unaffected.

Keystone species

A species that plays a critical role in maintaining the structure, stability, and function of an ecosystem.

Trophic cascade

A series of drastic changes in community structure across multiple trophic levels triggered by the removal or disruption of a key species.

Structural adaptation

A physical or anatomical feature of an organism's body that enhances its survival and reproduction in its environment.

Physiological adaptation

An internal systemic process or body function that assists an organism in surviving in its environment.

Behavioural adaptation

An action, activity, or learned conduct performed by an organism that enhances its survival and reproduction.

Hydrophyte

An aquatic plant adapted to live entirely or partially submerged in or floating on water.

Mesophyte

A terrestrial plant adapted to moderate environments that are neither excessively wet nor excessively dry.

Xerophyte

A plant structurally and physiologically adapted to survive in dry, hot, and arid conditions.

Crassulacean Acid Metabolism (CAM) Photosynthesis

A physiological pathway in arid plants where stomata open only at night to fix $\text{CO}_2$ into malic acid, which is stored in vacuoles and converted back to $\text{CO}_2$ for daytime photosynthesis.

Lignotuber

A swollen underground stem base in fire-adapted plants containing food reserves and dormant buds that allow sprouting after bushfires.

Epicormic buds

Dormant buds located beneath plant bark that grow into new shoots following damage from fire.

Halophyte

A plant adapted to live and grow in habitats with high salt concentrations.

Viviparity

A condition in plants where seeds germinate and begin development while still attached to the parent plant before being dispersed.

Pneumatophores

Specialised aerial roots in mangroves that project upward out of mud and water to uptake oxygen.

Tropism

Directional growth of a plant in response to an environmental stimulus such as light, gravity, or touch.

Nastic movement

Non-directional movement of plant tissues in response to an environmental stimulus such as touch, temperature, or light.

Counter-Current Heat Exchange System

A vascular arrangement where warm arterial blood running adjacent to cool venous blood transfers heat to maintain core temperature or protect body extremities.

Torpor

A short-term physiological state of reduced metabolic rate, body temperature, and heart rate to conserve energy during extreme environmental stress.

Hibernation

Extended, long-term winter torpor marked by metabolic suppression to survive cold temperatures and seasonal food shortages.

Brumation

A winter metabolic dormancy in ectothermic reptiles triggered by reduced temperatures and shorter daylight hours.

Aestivation

Prolonged metabolic dormancy during hot, dry summer conditions to avoid desiccation and overheating.

Bioluminescence

The enzymatic production of light by a living organism via the oxidation of luciferin catalyzed by luciferase.

Genetic diversity

The total variety of distinct gene sequences and alleles present within individuals of a species or population.

Allele

An alternative form or variant of a specific gene.

Gene pool

The sum total of all alleles for all genes present in a population.

Gene flow

The transfer and exchange of alleles between distinct populations through the migration of individuals.

Biological fitness

A measure of an organism's capacity to survive, reproduce, and pass its alleles on to viable, fertile offspring.

Inbreeding depression

A reduction in biological fitness and survival caused by mating between closely related individuals, leading to elevated homozygosity and expression of harmful recessive alleles.

Distribution

The precise geographic range and environmental boundaries within which a species is located.

Abundance

The total quantity or count of individual organisms of a species in a given study area.

Endemic species

A species strictly native and naturally restricted to a specific geographical region.

Latitudinal diversity gradient

The biogeographical pattern where species richness peaks in warm equatorial regions and declines toward polar biomes.

Gause's Principle of Competitive Exclusion

The ecological law stating that two distinct species competing for identical limiting resources cannot coexist in the exact same ecological niche.

Quadrat

A standard sample frame (frequently $\text{1m}^2$) placed randomly to quantitatively assess the density or percentage cover of sessile or immobile organisms.

Transect

A sampling line placed across an environment to systematically profile species distribution shifts relative to abiotic gradients.

Carrying capacity ($K$)

The maximum stable population density or size that a given environment's resources can sustainably support.

Density-dependent regulators

Biotic factors (e.g., resource competition, predation, disease) whose mortality impact on a population intensifies as population density increases.

Density-independent regulators

Abiotic events or physical environmental conditions (e.g., floods, bushfires, sudden freezes) that alter population size regardless of local density.

Shelford's Law of Tolerance

An ecological principle stating that an organism's survival and geographic distribution are limited by abiotic factors defining its optimum range, physiological stress zone, and zone of intolerance.