Genetic Control of Cell Function and Inheritance

Vocabulary flashcards covering key terms from the lecture notes on genetic control, inheritance, and chromosomal disorders.

Chromosome

A DNA-containing structure that carries genes; humans have 23 pairs.

Karyotype

The complete set of chromosomes of an individual, in number and appearance.

Phenotype

The observable traits or characteristics resulting from gene expression.

Genotype

The genetic makeup of an individual—the alleles present at a locus.

Allele

One of two or more variant forms of a gene at a given locus.

Homozygous

Having two identical alleles at a gene locus.

Heterozygous

Having two different alleles at a gene locus.

Dominant

An allele that expresses its trait when present in one or two copies.

Recessive

An allele that expresses its trait only when two copies are present.

Autosomal

Relating to non-sex chromosomes; inheritance patterns on autosomes.

Sex-linked (X-linked)

Genes located on the X chromosome; often show different male vs female expression.

Carrier

An individual who carries one copy of a recessive mutation but is usually phenotypically normal.

Gene locus

The specific location of a gene on a chromosome.

Mutation

A permanent change in the DNA sequence.

Oncogene

A gene that can cause cancer when mutated or overexpressed.

Tumor suppressor gene

A gene that restrains cell growth; loss can lead to cancer.

SNP (Single nucleotide polymorphism)

A single base-pair variation in the genome that is common in the population.

Aneuploidy

Abnormal number of chromosomes in a cell.

Genomics

The study of the structure, function, and mapping of genomes.

Pharmacogenomics

The study of how genetic variation affects drug response.

Translocation

A chromosomal rearrangement where segments exchange between chromosomes.

Marfan syndrome

A connective tissue disorder due to FBN1 gene mutation affecting skeleton, eyes, and heart.

Neurofibromatosis

A genetic disorder causing nerve-associated tumors; NF1 or NF2 types.

Xanthoma

Fatty plaque under the skin associated with high cholesterol.

Xanthelasma

Yellow cholesterol-rich deposits around the eyelids.

Familial hypercholesterolemia

Inherited condition with elevated LDL due to defective LDL receptors.

LDL receptor

Liver cell receptor that clears LDL cholesterol from blood; loss leads to high LDL.

APC gene

Tumor suppressor gene on 5q21; mutations raise colon cancer risk.

Lisch nodules

Hamartomas on the iris seen in neurofibromatosis type 1.

Café-au-lait spots

Light brown skin patches common in NF1.

PKU (Phenylketonuria)

Autosomal recessive metabolic disorder due to phenylalanine hydroxylase deficiency.

CFTR

Gene encoding a chloride channel; mutations cause cystic fibrosis.

Cystic fibrosis

Autosomal recessive disease with thick mucus affecting lungs and pancreas.

Wilson disease

Copper accumulation disorder due to ATP7B mutation; Kayser-Fleischer rings.

Hexosaminidase A

Enzyme deficient in Tay-Sachs disease; leads to lipid accumulation and neurodegeneration.

Fragile X syndrome

X-linked disorder caused by CGG repeat in FMR1 gene; features include large ears, long face, macroorchidism, intellectual disability.

G6PD deficiency

X-linked enzyme defect causing hemolysis under stress; Heinz bodies on blood smear.

Down syndrome (Trisomy 21)

Nondisjunction leading to three copies of chromosome 21; characteristic facial features and intellectual disability.

Turner syndrome (Monosomy X)

Female with a missing or partial X chromosome; features include short stature and webbed neck.

Klinefelter syndrome (XXY)

Male with an extra X chromosome; features include tall stature, gynecomastia, small testes.

Colonoscopy (regarding prevention)

An example of secondary prevention; screening to detect disease earlier.

Aneuploidy example

Having an abnormal number of chromosomes in a cell (e.g., trisomy, monosomy).