Bespoke Education SAT2 Biology - Diversity and Evolution

Adaptive Radiation
The development of several new species from one species that enters a new ecosystem
A mode of speciation induced when the ancestral population becomes segregated by a geographical barrier
Amniote Egg
The embryos of reptiles, birds, and mammals with four membranes: the amnion, yolk sac, allantois, and chorion; adapted for birth on dry land
The class of chordates who lay their eggs and complete their first life stage in water, and can carry out limited breathing through their skin; e.g. frogs and salamanders
Analogous Structures
Structures in different species with similar functions but different structures; do not indicate common ancestry
A segmented worm, such as an earthworm, with a hydrostatic skeleton
The class of arthropods with eight legs; e.g. spiders and scorpions
An animal with three segmented body regions, a jointed exoskeleton, and an open circulatory system; includes arachnids, insects, and crustaceans
The vertebrate class of birds, characterized by feathers, hollow bones, beaks, and a four-chambered heart
Bottleneck Effect
Genetic drift resulting from a drastic reduction in population size
A group of plants that lack xylem and phloem; includes mosses
An evolutionary trend in the animal kingdom toward centralization of neural and sensory organs in the head or front of the body
The phylum of animals having a notochord and pharyngeal gill slits at some point in their development; includes the vertebrates
A phylogenetic tree that branches repeatedly, suggesting a classification of organisms based on the time sequence in which evolutionary branches arise
The taxonomic category of classification consisting of related orders
The phylum of aquatic animals with radial symmetry and two layers of cells, such as jellyfish and hydras
The stinging cells on the tentacles of members of the phylum Cnidaria; contains organelles called cnidocysts that produce toxins
Convergent Evolution
The development of a similar trait in organisms with different evolutionary histories
The class of marine arthropods such as lobsters, shrimp, crabs, and barnacles
Photosynthetic, oxygen-producing bacteria
One of two distinct evolutionary lines of coelomates, consisting of echinoderms and chordates
Directional Selection
Natural selection that favors one extreme of a trait
Disruptive Selection
Natural selection that favors both extremes of a trait
The phylum of sessile or slow-moving animals with radial symmetry, water vascular system and tube feet, such as sea stars
The use of metabolic energy to maintain a constant body temperature
The taxonomic category of classification consisting of related genera
The ability of an organism to grow to maturity and produce fertile offspring
A preserved remnant or impression of an organism that lived in the past
Founder Effect
Random change in the gene pool that occurs in a small colony of a population
Gene Flow
The gain or loss of alleles from a population by the movement of individuals into or out of the population
Gene Pool
All the genes in a population at one time
Genetic Drift
Changes in the gene pool of a small population due to chance
The taxonomic category of classification consisting of related species
The theory that evolution is a product of slow, steady changes
Homologous Structures
Structures in different species with different functions that have similar structures because of common ancestry
Hydrostatic Skeleton
A skeletal system composed of fluid held under pressure in a closed body compartment; the main skeleton of most cnidarians, flatworms, nematodes, and annelids
Filaments that collectively make up the body of a fungus
An incredibly diverse class of arthropods with six legs and wings
Jointed Appendages
A defining characteristic of arthropods that allows for more specialized and more versatile body parts
The taxonomic category of classification consisting of related phyla
Lamarck, J.B.
A 19th century scientist who theorized that modifications an organism acquires during its lifetime can be passed along to its offspring
The class of chordates who carry out internal gestation, and have hair and mammary glands
The animal phylum composed of snails, oysters, squids, etc...; distinctive structures include the mantle, foot, and gill
The kingdom of unicellular prokaryotes called bacteria
Natural selection
The success or failure of groups within populations based on how well suited they are to their environment
The phylum of roundworms found in aquatic habitats, wet soil, moist tissues of plants, and body fluids of animals
A longitudinal, flexible rod formed from mesoderm and located between the gut and the nerve cord in all chordate embryos
The taxonomic category of classification consisting of related families
The taxonomic category of classification consisting of related classes
The animal phylum composed of bilaterally symmetric flatworms
The phylum of filter-feeding animals commonly called sponges
The kingdom that contains the unicellular eukaryotes and closely related multicellular organisms called protists
A member of one of two distinct evolutionary lines of coelomates, consisting of the annelids, mollusks, and arthropods
Punctuated Equilibrium
The theory that most species don't evolve much for most of their evolutionary history, with short periods of rapid speciation interspersed
Radioactive Dating
A method of determining the age of fossils and rocks using half-lives of radioactive isotopes
The vertebrate class of reptiles, characterized by scales and an amniotic egg; represented by lizards, snakes, turtles and crocodiles
Hair-like structures on the ventral side of an annelid which are used for grip
The development of a new species from another species
Stabilizing Selection
Natural selection that favors the middle ground between two extremes of a trait
A mode of speciation that produces a reproductively isolated subpopulation in the midst of its parent population
A vascular plant that has a conducting system of xylem and phloem
Vestigial Structure
A structure that is of little or no use to the organism
Water Vascular System
In echinoderms, a radially arranged system of water-filled canals that provide movement and circulate water, facilitating gas exchange and waste disposal