HG - week 3

Cytogenetics

The branch of genetics studying the structure and function of chromosomes.

Diploid (2n)

The full set of chromosomes in a cell, which contains two complete sets from each parent.

Haploid (n)

A single set of unpaired chromosomes, typically found in gametes such as sperm and eggs.

Autosomal Chromosomes

Chromosomes that are not sex chromosomes; in humans, these are pairs 1-22.

Karyotype

A photograph or digital image of the chromosomes in a cell, organized into pairs.

Polyploidy

The condition of having extra complete sets of chromosomes.

Aneuploidy

The condition of having an abnormal number of chromosomes, either more or fewer than the normal set, but not by an entire set.

Nondisjunction

The failure of chromosomes to separate properly during cell division, leading to aneuploidy.

Turner Syndrome

A condition resulting from a monosomy of the X chromosome in females, characterized by short stature and infertility.

Klinefelter Syndrome

A condition in males caused by the presence of an extra X chromosome, leading to infertility and other physical traits.

Robertsonian Translocation

A chromosomal alteration that occurs when the long arms of two acrocentric chromosomes fuse at their centromeres.

G-banding

A technique used to stain chromosomes to produce a distinct banding pattern that aids in their identification.

Trisomy 21

A genetic condition also known as Down syndrome, characterized by three copies of chromosome 21.

Phenotype

The observable characteristics or traits of an organism determined by both genetics and the environment.

Genotype

The genetic constitution of an individual organism.

Chromosomal Aberrations

Alterations in the normal structure or number of chromosomes, which can lead to genetic disorders.

Deletions

A type of chromosomal abnormality where a section of DNA is lost.

Inversions

A chromosomal rearrangement in which a segment of a chromosome is reversed end to end.

Duplication

A chromosomal alteration in which a segment of the chromosome is copied, resulting in extra genetic material.

Amniocentesis

A medical procedure used to obtain a sample of amniotic fluid for genetic testing.

Chorionic Villus Sampling

A prenatal test that involves taking a sample of tissue from the placenta for genetic analysis.

Chromosome Painting

A technique using fluorescent dyes that allows for identification of chromosomal abnormalities.

Giemsa Staining

A method of staining chromosomes that reveals the structure and organization of the DNA.

Fertilisation

The process by which male and female gametes fuse to form a zygote.

Chromosome Structure

The physical composition of a chromosome, including centromeres and arms.

Gametes

Sex cells (sperm and ovum) that contain half the number of chromosomes of somatic cells.

Centromeres

The region of a chromosome where the two sister chromatids are joined.

Metaphase

The stage of cell division where chromosomes are aligned in the center of the cell before separation.

Anaphase

The phase in cell division during which chromosomes move away from one another to opposite poles of the cell.

Telophase

The final stage of cell division where nuclei reform and chromosomes de-condense.

Sister Chromatids

Identical copies of a chromosome that are joined together at the centromere.