BIOMED 2.2

tightly coiled DNA that is found in the nuclei of cells

Chromosome

one half of a chromosome

Chromatid

chromosome pairs, one from each parent, having similar gene composition, size, and structure

Homologous chromosomes:

the central region joining two sister chromatids

Centromere:

any cell in the human body that is not a sex cell (egg or sperm)

Somatic cell

specialized reproductive cells (sperm in males, eggs or ova in females) that combine during fertilization to create a new organism

Sex cell

a process that takes place in the nucleus of a dividing cell. Mitosis involves the doubling and separation of genetic material and results in the formation of two new nuclei, which each have the same number of chromosomes as the parent nucleus.

mitosis

a medical imaging technique that uses magnetic fields and radio waves to take pictures of the soft tissues of the body

Magnetic resonance imaging (MRI)

the spread of cancerous cells to other tissues or parts of the body

Metastasis

a lump or mass of cells caused by uncontrolled cell division. Tumors are categorized as benign (non-cancerous) or malignant (cancerous).

Tumor

a cancerous tumor that will grow and spread to invade other tissues or parts of the body

Malignant

a tumor that is not cancerous. Benign tumors are generally considered harmless.

Benign

a three-dimensional polymer made of amino acid monomers. A protein’s form and function are determined by a cell’s nucleic acid sequence.

protein

a rare change in genetic material, which ultimately creates genetic diversity within a species

mutation

a sequence of nucleotides that codes for a protein, resulting in a specific phenotype

Gene

the creation of a protein from a DNA template

protein synthesis

a genetic trait in which the associated phenotype is seen in an individual who has only one copy of the gene associated with the trait

Dominant trait

a trait that is evident only when an organism inherits two copies of a recessive allele for a specific gene

recessive trait

a complete set of the genes in one organism

genome

any of the alternative forms of a gene that could occur at the same place on a chromosome. For example, the genes responsible for blood type that are found on chromosome 9.

allele

the likely course a disease will take over an individual’s lifetime

prognosis

the physical and physiological traits of an organism that are determined by the organism’s genetic makeup

phenotype

all or part of the genetic constitution of an individual or group

genotype

a diagram that shows the occurrence of phenotypes through several generations of genetically related individuals. Symbols are used to represent each individual.

pedigree

an error during mitosis or meiosis, in which members of a pair of homologous chromosomes or sister chromatids fail to move apart properly

Nondisjunction

a signaling molecule produced by glands. A hormone induces a specific effect on the activity of cells.

hormone

a laboratory technique for amplifying DNA in vitro. It uses a thermocycler, primers, DNA polymerase, and nucleotides.

PCR

a degradative enzyme that recognizes specific nucleotide sequences and cuts DNA at these sequences called restriction sites. It is also known as a restriction endonuclease.

Restriction enzyme

An individual's complete set of chromosomes, arranged in a standardized, numbered, and visual profile.

Caryotype

a chromosome that is not directly involved in determining sex (such as chromosomes 1–22), as opposed to the sex chromosomes X and Y

Autosome

one of the pairs of chromosomes that determines the sex of an individual. The sex chromosomes are X and Y.

sex chromosome