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
Insertion
a type of mutation that involves the addition of one or more nucleotides into a segment of DNA
degenerate code
multiple codons, or sets of three nucleotides, can code for the same amino acid during protein synthesis
mutagens
a chemical or physical agent capable of inducing changes in DNA called mutations
carcinogens
a substance, organism or agent capable of causing cancer
Molecular clock
measures the number of changes, or mutations, which accumulate in the gene sequences of different species over time
Human Immunodeficiency Virus
a virus that attacks cells that help the body fight infection, making a person more vulnerable to other infections and diseases
lymphocytes
a type of white blood cell that is part of the immune system. There are two main types of lymphocytes: B cells and T cells
Acquired ImmunoDeficiency Syndrome
A disease caused by the human immunodeficiency virus (HIV). People with acquired immunodeficiency syndrome are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called AIDS
simian immunodeficiency virus
members of theLentivirusgenus of Retroviruses that infect nonhuman primates such as monkeys, chimpanzees, and gorillas
Zoonotic transmission
an infectious disease that is transmitted between species from animals to humans (or from humans to animals)
Retrovirus
A type of virus that has RNA instead of DNA as its genetic material. It uses an enzyme called reverse transcriptase to become part of the host cells’ DNA
reverse transcriptase
an enzyme that converts RNA into DNA, commonly found in retroviruses like HIV
Bioinformatics
an interdisciplinary field of science that develops methods and software tools for understanding biological data
Homology
similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor
BLAST
finds regions of similarity between biological sequences. The program compares nucleotide or protein sequences tosequence databasesand calculates the statistical significance
Mitochondria DNA
thecircular chromosomefound inside the cellular organelles called mitochondria
parsimony
the principle that, out of all possible explanations for a phenomenon, the simplest of the set is most likely to be correct
Root
the central trunk of a cladogram that indicates the ancestor common to all groups branching from it. A cladogram uses branching lines that end in a clade, which is a group of organisms sharing a common hypothetical ancestor
Outgroup
assumes that one or more of the taxa are divergent from the rest of the taxa (ingroup)
Reclassification
updating the classification of an organism based on modern cladistic techniques
Red Pandas
bamboo eaters native to Asia’s high forests. Despite these similarities and their shared name, the two species are not closely related
Figworts
any of a genus (Scrophularia) of chiefly herbaceous often fetid plants of the snapdragon family with terminal cymes of small purple, yellow, or greenish flowers
Domain
the highest taxonomicrankin the hierarchical biological classification system, above the kingdom level. There arethree domains of life, the Archaea, the Bacteria, and the Eucarya
Eubacteria
prokaryotic microorganismsconsisting of a single cell lacking a nucleus and containing DNA is a single circular chromosome
Archaea
single-celled microorganisms with structure similar to bacteria. They are evolutionarily distinct from bacteria and eukaryotes and form the thirddomain of life
Eukaryotes
any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus
endosymbiotic theory
proposes that mitochondria originated as free-living Alphaproteobacteria that were internalized by a pre-eukaryotic host cell, leading to the formation of the modern eukaryotic cell
