The Chromosomal Basis of Inheritance

Flashcards covering key concepts from the lecture on the chromosomal basis of inheritance and related genetic principles.

Gene

A segment of DNA located along chromosomes that is responsible for hereditary traits.

Chromosome Theory of Inheritance

The theory stating that Mendelian genes have specific loci on chromosomes and undergo segregation and independent assortment.

Law of Segregation

The principle that during gamete formation, the two alleles for each gene separate from each other.

Law of Independent Assortment

The principle that alleles of genes on nonhomologous chromosomes assort independently during gamete formation.

Mitosis

A type of cell division that results in two daughter cells, each having the same number and kind of chromosomes as the parent nucleus.

Meiosis

A specialized type of cell division that reduces the chromosome number by half, resulting in four haploid cells.

Drosophila melanogaster

The scientific name for the fruit fly, a common model organism in genetic studies.

Mutant Phenotype

An alternative trait that differs from the wild type phenotype, often due to genetic mutation.

Sex-Linked Gene

A gene located on one of the sex chromosomes, such as the X or Y chromosome.

Aneuploidy

A condition in which there is an abnormal number of chromosomes in a cell, resulting from nondisjunction.

Polyploidy

A condition in which an organism has more than two complete sets of chromosomes, common in plants.

Chromosomal Alterations

Changes in chromosome structure or number that can cause genetic disorders.

Barr Body

An inactivated X chromosome present in female mammalian cells.

Recombination

The process by which genetic material is physically mixed through mechanisms like crossing over, resulting in new allele combinations.

Linkage Map

A genetic map based on recombination frequencies that shows the relative positions of genes on a chromosome.

Nondisjunction

An error in cell division during meiosis where homologous chromosomes or sister chromatids fail to separate properly.

Color Blindness

A common X-linked recessive disorder that affects the perception of colors.

Down Syndrome

An aneuploid condition caused by three copies of chromosome 21, leading to developmental and intellectual challenges.

Klinefelter Syndrome

A genetic condition in males characterized by an extra X chromosome (XXY), which can affect physical and reproductive development.

Turner Syndrome

A condition resulting from monosomy X in females (X0), leading to sterility and other physical features.

Cri du Chat Syndrome

A genetic disorder caused by a deletion on chromosome 5, leading to intellectual disability and distinctive cry.