MI Unit 2

PLTW Medical Interventions Unit 2

Gene

A segment of DNA on a chromosome that codes for a specific trait

genetic counselor

person trained to collect, analyze, and explain data about human inheritance patterns

Genome

the complete instructions for making an organism, consisting of all the genetic material in that organism's chromosomes

genetic testing

The use of methods to determine if someone has a genetic disorder, will develop one, or is a carrier

genetic disorder

An abnormal condition that a person inherits through genes or chromosomes

single-gene trait

trait controlled by one gene that has two alleles

autosomal dominant

inheritance pattern of a dominant allele on an autosome; requires only ONE copy to be expressed

autosomal recessive

two copies of an abnormal gene must be present in order for the disease or trait to develop

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

multifactorial inheritance

an interaction between genes and the environment that contributes to a phenotype or trait

chromosomal disorders

deletion, inversions, duplications, and translocations that alter the typical amount of genetic material on a chromosome; can be seen on a karyotype

Mitochondrial disorders

Caused by mutations in mitochondrial DNA (not in the nucleus). Mitochondrial DNA is only passed down by the mother (only one copy of the gene). Deals with energy and metabolism. It usually affects all cells in the body, but not always.

Karyotype

A display of the chromosome pairs of a cell arranged by size and shape.

polymerase chain reaction (PCR)

A technique for amplifying DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.

primer

A short segment of DNA that acts as the starting point for a new strand

Denaturing

separates the DNA molecule; occurs at HIGHER temperatures

Annealing

binding of primers to single DNA strands (in PCR)

Extending

the extension of the DNA molecule with the help of Taq polymerase

Taq polymerase

A heat-stable form of DNA polymerase extracted from bacteria that live in hot environments, such as hot springs, that is used during PCR technique

Thermal cycler

An instrument that automatically cycles through different temperatures used to complete PCR reactions

Genotype

genetic makeup of an organism

Phenotype

An organism's physical appearance, or visible traits.

single nucleotide polymorphism (SNP)

One base-pair variation in the genome sequence

blunt ends

Restriction fragments with no overlapping ends and that never combine with another type of DNA

sticky ends

Single stranded ends of DNA left after cutting with enzymes

Electrophoresis

method of separating DNA by size and shape

chorionic villus sampling (CVS)

A technique associated with prenatal diagnosis in which a small sample of the fetal portion of the placenta is removed for analysis to detect certain genetic and congenital defects in the fetus.

amniocentesis

needle puncture of the amniotic sac to withdraw amniotic fluid for analysis via aspiration

gene therapy

The introduction of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder

CRISPR/Cas9

a revolutionary gene editing technique derived from the immune system of simple prokaryotes used to modify specific sequences of DNA

Vectors

An organism that transmits disease by conveying pathogens from one host to another

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

liposomes

artificial membrane-bound vesicles that can carry DNA; made of lipids

Adeno-associated virus

replicates only in cells infected with adenovirus

Retrovirus

An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.

Lentivirus

A virus characterized by a long incubation period.

in vivo gene therapy

gene is delivered directly into the body

in vitro

modification of living cells that occurs OUTSIDE of the organism, such as in a test tube or petri dish

cystic fibrosis (CF)

hereditary disorder of the exocrine glands characterized by excess mucus production in the respiratory tract, pancreatic deficiency, and other symptoms

CFTR gene

a gene that codes for a protein involved in chloride and water transport across membranes. In patients with cystic fibrosis, a mutation in this gene disrupts chloride and water transport across membranes. The end result is production of thick and sticky mucus that obstructs the airways in the lungs and the ducts in the pancreas.

preimplantation genetic diagnosis

In assisted reproductive technology, the determination of genetic abnormalities in the embryo before it is transferred to the uterus

Cloning

A process in which a cell, cell product, or organism is copied from an original source.