Chapter 15: The Chromosomal Basis of Inheritance

These flashcards cover key vocabulary related to the chromosomal basis of inheritance as discussed in the lecture.

Drosophila melanogaster

A common species of fruit fly chosen by Thomas Hunt Morgan for genetic studies.

Mendelian inheritance

Inheritance patterns that follow the laws established by Gregor Mendel, linked to the behavior of chromosomes.

wild type

The typical phenotype that occurs most frequently in a population.

mutant phenotype

Traits that are alternative to the wild type, resulting from mutations.

X chromosome

One of the two sex chromosomes in humans; females typically have two (XX), while males have one (XY).

SRY gene

The gene on the Y chromosome responsible for the development of male testes.

sex-linked gene

A gene located on a sex chromosome.

hemizygous

Having only one allele of a gene, as seen in males for X-linked genes.

nondisjunction

The failure of homologous chromosomes to separate properly during meiosis, leading to an abnormal number of chromosomes.

aneuploidy

An abnormal number of chromosomes in a cell, which can result from nondisjunction.

polyploidy

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

deletion

A type of chromosomal alteration where a segment of chromosome is removed.

duplication

A type of chromosomal alteration in which a segment of chromosome is duplicated.

inversion

A chromosomal alteration in which a segment of DNA is reversed within a chromosome.

translocation

A chromosomal alteration where a segment of one chromosome breaks off and attaches to another chromosome.

Down syndrome

A genetic disorder caused by trisomy of chromosome 21, leading to various developmental changes.

Klinefelter syndrome

A genetic condition in males characterized by the presence of an extra X chromosome (XXY).

Turner syndrome

A condition resulting from the presence of only one X chromosome (X0) in females.

genomic imprinting

A process where certain genes are expressed in a parent-of-origin-specific manner.

Barr body

An inactivated X chromosome in a female mammal, which condenses and is not expressed.

recombinant types

Offspring that exhibit new combinations of traits different from either parent.

linkage map

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