biology unit 5 Flashcards
Theory of Evolution
States that species change over time and ultimately originated from a common ancestor
Theory of Intelligent Design
States that certain features of living organisms are best explained by an intelligent cause rather than through undirected processes
Fossil
Preserved remains or traces of ancient organisms
strata
Layers of rock or soil piled up over time.
Fossil record
Physical layers preserved remains of plants, animals, other organisms that lived long ago
Relative dating
Dating which works to determines which of two fossils is older or younger
Absolute dating
Dating of fossils that works to determine the approximate age in years.
Molecular clocks
Function like timers used by scientists to figure out when changes in species occurred.
Geologic time scale
A way scientists divide Earth’s history into different periods
Organic molecules
Compounds that are composed of carbon atoms bonded to hydrogen
RNA World hypothesis
Theory in biology that RNA might have been the first organic molecule to develop
Last Universal Common Ancestor (LUCA)
Theory in biology suggesting that all living things on Earth today, like plants, animals, and bacteria, share a common ancestor
Endosymbiosis
Theory that suggests that large cells engulfed smaller cells
Phylogenetic tree
Chart that works like a family tree for different species
Heritable variations
Differences in traits passed down from parents to offspring through genetic inheritance, crucial for natural selection.
Mendelian genetics
Explains how traits pass from parents to offspring through genes, following predictable patterns
Alleles
Different versions of a gene that can occupy the same position on a chromosome,
Gene pool
The complete set of genes and their different alleles present within a population of a particular species.
Population
A group of organisms of the same species living in the same geographic area
Population genetics
A blend of evolutionary theory and Mendelian genetics, focuses on how evolution happens within these populations.
Mutations
Changes in genes that create new genetic variations.
Gene flow
Process that happens when individuals move in or out of a population
Genetic drift
Random fluctuation of allele frequencies in small populations
