Transmission Genetics and Mendelian Principles Vocabulary

Vocabulary flashcards generated from the Chapter 1 through Chapter 8 lecture transcript covering cellular errors, modes of reproduction, and Mendelian genetics.

Metacognitive skills

Critical thinking skills, specifically involving active reflection and self-evaluation regarding one's own understanding and learning process during lectures.

Disjunction

The cellular process combining the segregation of homologous chromosomes and the separation of sister chromatids during division.

Nondisjunction

An error in cellular division where homologous chromosomes fail to segregate or sister chromatids fail to separate properly.

Aneuploid

Describing a cell or organism that has an abnormal chromosome number that is not an exact multiple of the diploid set, having an extra chromosome ($n+1$) or missing one ($n-1$).

Trisomy 21

A chromosomal condition caused by nondisjunction resulting in three copies of chromosome 21 instead of two; also known as Down syndrome.

Cohesin

The molecular protein glue that holds tetrads or sister chromatids together, which can degrade over time during extended meiotic arrest.

Turner syndrome

A monosomy condition represented as XO where an individual inherits only one X chromosome, leading to sterility and physical features like extra skin on the neck.

Klinefelter syndrome

A chromosomal condition where an individual has an extra sex chromosome (XXY), producing male individuals who are typically sterile and may develop female secondary sexual characteristics.

SRY gene

The sex-determining region locus located on the Y chromosome in human biology that acts as the signal to produce maleness.

Deletion

A type of chromosomal rearrangement caused by double-strand DNA breaks resulting in the loss of a gene sequence or chromosome segment.

Duplication

A chromosomal rearrangement in which a segment of DNA is duplicated, providing redundant genetic material that evolution can modify.

Inversion

A chromosomal rearrangement where the internal sequence of genes on a chromosome segment is reversed.

Translocation

A chromosomal rearrangement wherein a portion of one chromosome breaks off and attaches to a non-homologous chromosome.

Gonochorism

A sexual reproduction system characterized by having distinct individual organisms of male and female sexes.

Hermaphrodites

Organisms that possess both egg-producing and sperm-producing structures or cells within the same individual.

Parthenogenesis

A form of asexual reproduction, sometimes referred to as virgin birth, in which offspring develop from unfertilized gametes.

Heterogametic sex

The sex within a species that possesses two different sex chromosomes, such as WZ females in birds and lizards or XY males in humans.

Homogametic sex

The sex within a species that possesses two identical sex chromosomes, such as ZZ males in birds and lizards or XX females in humans.

Allele

Alternative forms of a gene located at the same locus on homologous chromosomes that result in different traits.

Locus

The specific physical location or segment of DNA on a chromosome where a particular gene resides.

Genotype

The specific genetic constitution or set of alleles that make up the DNA of an organism.

Phenotype

The observable physical characteristics, functions, and appearance of an organism resulting from its genotype.

Homozygous

Having identical alleles at a specific gene locus on both homologous chromosomes.

Heterozygous

Having two different alleles at a specific gene locus on homologous chromosomes.

Monohybrid

An organism that is heterozygous with respect to a single gene locus being studied in a cross.

Principle of dominance

Mendel's concept stating that in a heterozygote, one allele masks or determines the phenotype over a recessive allele at the same locus.

Law of segregation

Mendel's principle stating that the two alleles for a gene separate during gamete formation so that each gamete carries only one allele.

Law of independent assortment

Mendel's principle stating that alleles of different genes assort independently of one another during gamete formation.

Rule of multiplication

A rule of probability used for independent simultaneous events stating that the joint probability is calculated by multiplying the individual probabilities.

Rule of addition

A rule of probability used for mutually exclusive dependent alternative outcomes stating that the overall probability is found by adding the individual probabilities.