Biology Module 3: Effects of the Environment and Evolution

Comprehensive vocabulary flashcards covering Module 3: Effects of the Environment on Organisms, Adaptations, and the Theory of Evolution.

Ecosystem

A combination of all the organisms; a community of living and nonliving things that work together, consisting of abiotic (soil, water, air) and biotic parts (flora, fauna).

Abiotic Factors

The nonliving components of an ecosystem, such as soil, water, air, temperature, and light intensity.

Biotic Factors

The living parts of an ecosystem, including flora, fauna, food abundance, and the number of competitors or predators.

Selection Pressures

All the factors of an ecosystem that influence changes of survival for organisms within that environment.

Ecology

The study of living things and their environment, focusing on the inter-relationships between lifeforms and environmental factors.

Transects

A narrow strip drawn to scale that crosses an entire study area to provide an easy method of representing variation and distribution.

Quadrat

A simple wire, wooden, or plastic frame dropped on the ground at random to calculate the average number of organisms per unit area, used for plants and slow-moving animals.

Capture-mark-recapture

A sampling technique used to estimate the abundance of mobile animal populations by marking a sample and later observing the ratio of marked to unmarked individuals in a second sample.

Adaptation

A characteristic that an organism has inherited, arising via mutation, that makes it suited for its environment.

Structural Adaptation

Physical features related to how an organism is built, such as the waxy leaves of Eucalypts or the muscular shoulders of a Wombat.

Physiological Adaptation

Internal processes related to how an organism functions, such as salt-tolerant plants accumulating ions or animals slowing their metabolic rates.

Behavioural Adaptation

Actions or activities related to how an organism acts, such as penguins huddling in packs or the rapid response of a Venus flytrap.

Xerophytes

Plants with structural adaptations designed to maximise the absorption and storage of water while minimising water loss.

Biological Diversity

The variety of forms of life on Earth, including genetic makeup within a species, the variety of species, and the variation of ecosystems.

Natural Selection

The process whereby species with traits that enable them to adapt to their environment survive and reproduce, passing those genes to the next generation.

Macroevolution

Evolutionary changes that take place over millions of years and usually result in the emergence of new species.

Microevolution

Evolutionary changes that occur over shorter periods and result in changes within a particular species without creating a new species.

Convergent Evolution

When distantly related species evolve similar traits because they have moved to similar environments and are exposed to similar selection pressures.

Divergent Evolution

When an ancestral species radiates into a number of descendant species with both similar and different traits, often due to varying selection pressures.

Gradualism

The theory that populations slowly diverge by accumulating changes in characteristics over a long period of time.

Punctuated Equilibrium

An evolutionary theory suggesting that species experience short bursts of rapid change followed by long periods of stability.

Amino Acid Sequencing

A biochemical method where the sequence of amino acids in proteins is analysed to identify similarities and differences between organisms.

DNA Hybridisation

A process where DNA strands from two different organisms are separated and then mixed to determine how tightly they bind, indicating their level of relatedness.

Homologous Structures

Body parts in different species that have the same basic plan and evolutionary origin, representing divergent evolution.

Analogous Structures

Structures that look similar and serve common purposes but have different evolutionary origins, representing convergent evolution.

Vestigial Structures

Evolutionary remnants of body parts that once performed a function in an ancestor but are now functionless, such as the human appendix.

Biogeography

The study of the geographical distribution of organisms, both living and extinct.

Law of Superposition

A principle of fossil dating suggesting that fossils found further down in rock layers are older than those found higher up.

Relative Dating

A method of determining the age of fossils by comparing their position in rock layers relative to one another.

Absolute Dating

A technique using radioactive elements present in specimens to determine the actual age of a fossil.