Chromosomal Inheritance

Vocabulary flashcards covering key concepts in chromosomal inheritance and genetics.

Chromosomal inheritance

The transmission of genes on chromosomes from one generation to the next.

Genetic linkage

The tendency of genes located close together on a chromosome to be inherited together.

Meiosis

A type of cell division that results in four daughter cells, each with half the number of chromosomes of the parent cell, typically involved in gamete formation.

Independent assortment

The principle that alleles for different traits are distributed to sex cells (& offspring) independently of one another.

Segregation

The separation of alleles during gamete formation.

Autosome

Any chromosome that is not a sex chromosome.

Sex-linked gene

A gene located on a sex chromosome, which can lead to different inheritance patterns compared to genes on autosomes.

Recombination frequency

The percentage of offspring in a genetic cross that display new combinations of traits, used to determine how closely two genes are linked.

Chromosomal theory of inheritance

The theory that genes are located on chromosomes and that the behavior of chromosomes during meiosis explains Mendel's laws of inheritance.

Wildtype

The common phenotype observed in the natural state of an organism as opposed to mutant phenotypes.

Phenotype

The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

Pedigree analysis

A diagram that depicts the biological relationships between an individual and its ancestors, used to track inheritance patterns.

Punnett Square

A diagram used to predict the genetic outcome of a cross between two individuals.

Dihybrid cross

A genetic cross between two individuals that differ in two traits controlled by different genes.

Recombinant offspring

Offspring that show new combinations of parental traits due to recombination.

Gamete

A reproductive cell (sperm or egg) that contains half the genetic material of an organism.

Linkage map

A representation of the positions of genes on a chromosome based on recombination frequencies.

Centimorgan

A unit of measure for genetic linkage that represents a 1% frequency of recombination between two genes.

True-breeding

Organisms that, when mated, produce offspring that are identical for a specific trait.

Heredity

The passing on of traits from parents to offspring.

Mutation

A change in the DNA sequence of a gene, which can lead to new traits within a population.

Carriers

Individuals who carry and can pass on a genetic mutation but usually do not exhibit the associated phenotype.

Mendelian genetics

The branch of genetics that deals with the inheritance of traits established by Gregor Mendel.

Genetic map

An ordered list of the genetic loci along a particular chromosome.

Testcross

A cross between an individual with an unknown genotype and a homozygous recessive individual.

Double mutant

An organism that carries two different mutations, affecting two traits.

Mendel's laws

The two laws of inheritance formulated by Gregor Mendel: the law of segregation and the law of independent assortment.

Locus

The specific physical location of a gene or other significant sequence on a chromosome.

Statistical significance

A measure of whether the outcome of an experiment reflects a true phenomenon or is due to chance.

Transmission genetics

The study of how traits are passed from one generation to the next.

Meiosis II

The second division of meiosis, in which the two cells produced during Meiosis I divide again to form four haploid cells.

Recessive trait

A trait that is masked by the presence of a dominant trait and is only expressed in a homozygous state.

Dominant trait

A trait that masks the expression of a recessive trait in a heterozygous individual.

Parental phenotype

The phenotype of the parents in a genetic cross.

Animal model

A non-human species used in experiments to understand biological processes relevant to humans.

Phenotypic ratio

The ratio of different phenotypes in the offspring resulting from a genetic cross.

Gene mapping

The process of determining the position of genes on a chromosome.

Crossing over

The exchange of genetic material between homologous chromosomes during meiosis, leading to recombination.

Mutant allele

An allele that has undergone mutation and exhibits a different phenotype than the wildtype allele.

Phenotypic combinations

Different combinations of observable traits that result from the inheritance of different alleles.

Selection pressure

An environmental factor that influences which individuals in a population survive and reproduce.

Physical cause of heredity

The underlying genetic mechanisms that determine traits in organisms.