unit 7 set 5

Vocabulary flashcards about the history of life on Earth, based on lecture notes.

Abiotic Synthesis

The abiotic synthesis of small organic molecules, such as amino acids and nitrogenous bases.

Macromolecule Formation

The joining of small molecules into macromolecules, such as proteins and nucleic acids.

Protocell Formation

The packaging of molecules into protocells, membrane-enclosed droplets, whose internal chemistry differed from that of the external environment.

Self-Replication Origin

The origin of self-replicating molecules that made inheritance possible.

Early Atmosphere Composition

Early atmosphere was thick with water vapor, nitrogen, carbon dioxide, methane, ammonia, hydrogen, and hydrogen sulfide.

Adaptive Radiations

Periods of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological niches.

Homeotic Genes

Master regulatory genes that determine the location and organization of body parts.

Hox Genes

One class of homeotic genes. Changes in these genes and in the genes that regulate them can have a profound effect on morphology, thus contributing to the potential for evolutionary change.

Continental Drift

The movement of Earth's continents on great plates that float on the hot, underlying mantle.

Mass Extinctions

Loss of large numbers of species in a short period, resulted from global environmental changes that have caused the rate of extinction to increase dramatically.

Ribozymes

RNA catalysts that can make complementary copies of short pieces of RNA.

Fossil Record

The sequence in which fossils appear in the layers of sedimentary rock that constitute Earth's surface.

Relative Dating

Uses the order of rock strata to determine the relative age of fossils.

Radiometric Dating

Uses the decay of radioactive isotopes to determine the age of the rocks or fossils.

Endosymbiotic Hypothesis

Proposes that mitochondria and plastids (chloroplasts) were formerly small prokaryotes that began living within larger cells.