Biological Sciences Seminar Notes

A collection of flashcards covering key vocabulary terms from the Biological Sciences seminar notes.

stratigraphy

The study of rock layers (strata) and layering (stratification) used to date fossils in a relative sense.

radiometric dating

A method for determining the age of an object by measuring the radioactive isotopes present in the material.

half-life

The time required for half of the radioactive atoms in a sample to decay.

abiotic synthesis

The process of creating organic compounds from inorganic materials without biological influences.

protocell

An early precursor to a living cell, typically consisting of a lipid bilayer enclosing a mixture of organic molecules.

classification

The systematic arrangement of living organisms into categories based on shared characteristics.

monophyletic

A group of organisms that includes an ancestor and all its descendants.

paraphyletic

A group of organisms that includes an ancestor but not all of its descendants.

polyphyletic

A group of organisms that does not include the most recent common ancestor of its members.

microevolution

Evolutionary change within a species or small group of organisms, especially over a short period.

macroevolution

Large-scale evolution that leads to the formation of new species or groups over long periods.

fossil record

The history of life as documented by fossils, which provide evidence of past organisms.

sedimentary rock

Rock that is formed by the accumulation of sediments, often containing fossils.

ribozyme

A RNA molecule capable of acting as an enzyme to catalyze biochemical reactions.

RNA world hypothesis

The theory that RNA was one of the first molecules to provide the basis for life, acting as both genetic material and a catalyst.

stromatolite

Layered structures formed by the activity of prokaryotes, particularly cyanobacteria.

oxygen revolution

The significant increase in atmospheric oxygen levels caused by photosynthetic prokaryotes around 2.4 billion years ago.

serial endosymbiosis

The theory that eukaryotic cells originated through a series of symbiotic events involving different species.

multicellularity

The condition of being composed of multiple cells that are functionally integrated.

Cambrian explosion

A rapid diversification of life that occurred around 535-525 million years ago, leading to the emergence of most major animal phyla.

plate tectonics

The theory explaining the movement of Earth's lithospheric plates and its impact on geological processes.

continental drift

The gradual movement of continents across the Earth's surface over geological time.

Pangaea

The supercontinent that existed during the late Paleozoic and early Mesozoic eras that eventually split into the continents we recognize today.

Laurasia/Gondwana

Two supercontinents that formed part of Pangaea, each eventually breaking apart to form the northern and southern landmasses.