Biology Final Exam Study Guide Flashcards

Comprehensive vocabulary flashcards covering DNA Technology, Evolution, Evidence of Evolution, Speciation, and Animal Classification based on Mike's Biology Final Exam Study Guide.

Gel electrophoresis

A laboratory technique that separates DNA fragments according to size.

Transgenic organism

An organism that has received DNA from another source in a laboratory.

Plasmid

The structure that carries a gene of interest into a recipient cell during the creation of a transgenic organism.

Recombinant DNA

DNA produced when scientists combine DNA from different sources.

Recipient

The organism or cell that receives recombinant DNA in a transgenic procedure.

Somatic cell nuclear transfer

The process used to clone Dolly the sheep, which is most similar to asexual reproduction.

Embryonic stem cells

Cells that can differentiate into many specialized cell types.

Adult stem cells

Cells that generally can form a more limited range of cell types compared to embryonic stem cells.

CRISPR-Cas9

A technology primarily used to edit specific genes with high precision.

Evolution

Changes in heritable traits within a population across multiple generations.

Mutation

The ultimate source of new alleles in a population.

Directional selection

A type of natural selection that favors one extreme phenotype.

Disruptive selection

A type of natural selection that occurs when two or more extreme phenotypes are favored.

Stabilizing selection

A type of natural selection that favors the intermediate phenotype.

Sexual dimorphism

Physical differences between males and females apart from the sex organs, such as colored plumage or antlers.

Bottleneck effect

Occurs when a population is reduced to very few survivors, such as a buffalo population hunted nearly to extinction.

Founder effect

An evolutionary phenomenon that occurs when a small group establishes a new population.

Artificial selection

The process of humans choosing which animals reproduce, such as in creating purebred dog lines.

Gene flow

The movement of alleles into or out of a population through immigration or emigration.

Microevolution

Evolutionary change within a species or small group over a relatively short period.

Macroevolution

Major evolutionary change, including the formation of new species.

Paleontology

The scientific study of fossils and ancient life.

Fossil

Preserved evidence of life that is more than $10,000$ years old.

Biogeography

Evidence for evolution obtained by examining the geographic distribution of organisms.

Homologous structures

Structures inherited from a common ancestor but modified for different functions.

Analogous structures

Structures with similar functions that evolved independently in unrelated groups.

Vestigial structure

A reduced structure that was more functional in an ancestor.

Convergent evolution

When unrelated species independently evolve similar adaptations because they face similar selective pressures.

Clade

A group that includes an ancestor and all of its descendants.

Allopatric speciation

Speciation most directly caused by geographic isolation.

Sympatric speciation

Occurs when new species form while populations remain in the same geographic area.

Prezygotic barrier

A reproductive barrier that prevents reproduction before fertilization occurs.

Postzygotic barrier

A reproductive barrier that acts after fertilization has occurred.

Temporal isolation

A prezygotic barrier where species breed during different seasons.

Ecological isolation

A prezygotic barrier where species occupy different habitats and rarely meet to mate.

Behavioral isolation

A prezygotic barrier where species are separated by different songs, coloration, or mating dances.

Mechanical isolation

A prezygotic barrier where reproductive structures are incompatible and prevent mating.

Gametic isolation

A prezygotic barrier where sperm from one species cannot fuse with the egg of another species.

Hybrid inviability

A postzygotic barrier where a fertilized hybrid embryo forms but fails to develop or survive.

Hybrid infertility

A postzygotic barrier where a hybrid survives normally but cannot reproduce.

Hybrid breakdown

A postzygotic barrier where first-generation hybrids are fertile, but their offspring are weak or sterile.

Asymmetry

A characteristic of an animal with no regular arrangement of body parts.

Radial symmetry

A body plan where parts are arranged around a central axis.

Bilateral symmetry

A body plan where an animal can be divided into roughly mirror-image left and right halves.

Porifera

The phylum containing sponges, which lack true tissues.

Cnidaria

The phylum containing corals and jellyfish.

Cnidocytes

Specialized stinging cells unique to cnidarians.

Platyhelminthes

The phylum containing flukes and tapeworms.

Nematoda

The phylum containing pinworms and hookworms.

Annelida

The phylum containing leeches and earthworms.

Mollusca

The phylum containing snails, clams, and octopuses.

Arthropoda

The most successful animal phylum, characterized by an exoskeleton and jointed appendages.

Echinodermata

The phylum containing sea stars and sea urchins.

Chordata

A phylum whose members possess a notochord.

Vertebrate

An animal that has a backbone (vertebrae) to protect the nerve cord and provide muscle attachment points.

Endotherm

An animal that maintains body temperature using heat generated by its own metabolism.

Ectotherm

An animal that depends mainly on external environmental heat to regulate body temperature.