Chromosomes, Genetic Disorders and Inheritance Flashcards

Flashcards about Chromosomes, Genetic Disorders and Inheritance Patterns

Chromosomes

Structures made of DNA and proteins that carry genetic information.

Centromere

The center part of a chromosome.

Telomeres

The ends of a chromosome.

Chromatids

The arm of the chromosome.

Somatic Cells

Cells with 46 chromosomes (23 pairs).

Gametes

Cells with 23 chromosomes (1 set).

Autosomes

The first 22 pairs of chromosomes that control body traits.

Sex Chromosomes

The 23rd pair of chromosomes, XX = Female, XY = Male.

Karyotype

Photograph or diagram of an individual's chromosomes arranged in pairs.

Aneuploidy

The presence of an abnormal number of chromosomes.

Trisomy

Having three copies of a chromosome.

Monosomy

Having one copy of a chromosome.

Polyploidy

Having more than two complete sets of chromosomes.

Nondisjunction

Failure of chromosome pairs to separate properly during meiosis or mitosis.

Down Syndrome (Trisomy 21)

Having three copies of chromosome 21 instead of two.

Patau Syndrome (Trisomy 13)

Having three copies of chromosome 13 instead of two.

Edwards Syndrome (Trisomy 18)

Having three copies of chromosome 18 instead of two.

Deletion

Occurs when a part of a chromosome is missing.

Duplication

Occurs when a part of a chromosome is present in more than one copy.

Inversion

Occurs when a part of a chromosome is flipped and then reattached in place.

Translocation

Occurs when a part of one chromosome breaks off and attaches to another, non-homologous chromosome.

Fragile Site

Regions on chromosomes that are prone to forming gaps or breaks.

Cri du Chat Syndrome

Caused by a deletion on chromosome 5; symptoms include intellectual disability and a high-pitched cry.

Fragile X Syndrome

Cause: Fragile site on the X chromosome; Symptoms: Intellectual disability, behavioral challenges, long face, large ears.

Gene

A segment of DNA that codes for a specific trait.

Allele

A variant or form of a gene.

Genotype

The combination of alleles an individual has for a particular gene or set of genes.

Phenotype

The observable characteristics or traits resulting from the genotype.

Homozygous

Having two identical alleles for a particular gene.

Heterozygous

Having two different alleles for a particular gene.