Organisms, Populations, Evolution, and Genetics Flashcards

Vocabulary flashcards covering biological hierarchy, evolutionary concepts, mechanisms of variation, and Mendelian genetics based on lecture notes.

Organism

An individual biological entity.

Population

Two or more of the same organisms, primarily focused on change.

Community

Multiple populations that live together and interact.

Ecosystem

Includes abiotic (nonliving) things in a community.

Biosphere

All ecosystems and the planet put together as one.

Emergent Properties

Properties that arise through interactions among smaller parts put together.

Cell Theory

The principle that all organisms are made of cells, all cells come from preexisting cells, and life is continuous.

Scientific Theory

An idea with a large amount of evidence supporting it and no evidence disproving it.

Special Creation

The belief that the world was created by God.

Great chain of Being

Aristotle's organization of the pieces of the world by complexity.

Evolution

The change in genetic frequency of a population over time.

Natural Selection

A process by which evolution can occur, requiring trait variation, heritability, differential reproduction, and differential survival.

Fitness

A reference to how many offspring an individual has.

Homologies

Similarities between individuals because they both got a trait from a common ancestor.

Vestigial Traits

Structures in organisms that serve little or no function.

Adaptation

A trait that increases the fitness of the possessor.

Contrivance

An adaptation that has been modified to be something different now.

Exaptation

An adaptation that over time becomes a different type of trait; the trait that becomes a contrivance.

Atavism

A trait that very few individuals in a population have, such as some humans born with a tail.

Homoplasy

A trait shared between species because the traits both evolved independently through convergent evolution.

Genome

All the hereditary information in a cell passed to the next generation, including non-genes or junk DNA.

Gene Pool

All the alleles of all the genes in a population.

Genotype

All genes in an individual or a subset of them.

Alleles

Different versions of the same gene.

Homologous chromosomes

A pair of chromosomes where one is maternal and one is paternal.

Ploidy

The number of sets of chromosomes in a cell, such as haploid (1 set), diploid (2 sets), triploid (3 sets), or tetraploid (4 sets).

Crossing over

The exchange of genetic info between non-sister chromatids of homologous pairs during Meiosis I.

Nondisjunction

An event in meiosis I or meiosis II that results in gametes having an unequal number of chromosomes.

Unequal Crossover

An event where chromosomes do not line up properly, resulting in unequal crossover that can accumulate over generations and cause Huntington disease.

Transformation

A form of genetic variation in asexual reproduction where pores in a bacteria cause DNA to be integrated into the genome or exist as a plasmid.

Transduction

A mechanism of asexual genetic variation similar to transformation, but where the DNA is injected by viral particles.

Conjugation

A process where a conjugation tube is formed by a bacterial cell with a plasmid to send a replicated strand of DNA to a recipient bacterial cell.

Blending inheritance

The pre-Mendelian belief that an average offspring was just a blend of two parents.

Inheritance of acquired characteristics

The belief that traits or changes acquired during the lifetime of an individual persisted through generations.

Mendel's Law of Segregation

The principle stating that allele pairs separate during the formation of gametes in the process of meiosis.

Homozygous

Having two of the same allele for a gene, such as RR or rr.

Heterozygous

Having two different alleles for a gene, such as Rr.

Mendel's Law of Independent Assortment

The principle stating that alleles of different genes sort into gametes independently of each other.

Dihybrid cross

A cross designed to examine how two different genes and their traits are inherited at the same time from parent to offspring.

Test cross

Crossing an unknown genotype with a homozygous recessive individual for the same trait.