A3.2 HL only Flashcards
Classification
the process of arranging organisms, both living and extinct, into groups based on similar characteristics
binomial nomenclature
a system of naming plants and animals in which each species is given a name consisting of two terms of which the first names the genus and the second the species itself
taxa
a group of one or more populations of an organism or organisms seen by taxonomists to form a unit
paradigm shift
a fundamental change in the basic concepts and experimental practices of a scientific discipline
Convergent evolution
occurs when organisms that aren’t closely related evolve similar features or behaviours, often as solutions to the same problems
phyla
a major group of animals or in some classificationsplants sharing one or more fundamental characteristics that set them apart from all other animals and plants and forming a primary category of the animal or plant kingdom
Cladistics
a method of hypothesizing relationships among organisms
homologous traits
similarities in structures of these organisms even when the function was not the same
common ancestor
an ancestral group of organisms that is shared by multiple lineages
cladogram
a diagram that shows relationships between species
clade
a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor
node
the point on a stem where a leaf or leaves are, or have been attached
Homologous structures
similar physical features in organisms that share a common ancestor, but the features serve completely different functions
Pentadactyl limb
any limb that has five digits(e.g. five fingers or toes) Pentadactyl limbs are present in many species from many groups of organisms, including mammals, reptiles and amphibians
homologous molecule sequences
the degree of similarity in the genetic sequences of different proteins or molecules
Mutations
a change in a DNA sequence
Substitution
a type of mutation in which one nucleotide is replaced by a different nucleotide
Deletion
A type of genetic change that involves the absence of a segment of DNA