Genetics Lecture Notes

A comprehensive set of flashcards covering the key vocabulary and concepts related to Genetics as outlined in the lecture notes.

Genetics

Study of the hereditary and the variation of inherited characteristics.

Genes

DNA sequences that encode specific proteins.

Genome

A complete set of genetic information in a person’s cells.

Nucleotides

DNA consists of a sequence of these building blocks: A, G, C, and T.

Exome

Consists of the protein-coding regions of the genome; this accounts for <2% of the human genome.

Encoded

Genetic information is stored in DNA, and expressed in RNA and protein.

Modes of Inheritance

Patterns by which genes are transmitted in families.

Karyotype

Chart displaying 23 chromosome pairs in size order.

Autosomes

Pairs 1 to 22 of chromosomes which determine traits, but not sex.

Sex chromosomes

Pair 23 of chromosomes that codes for gender.

Alleles

Various forms of a gene that differ in DNA sequence.

Homozygous

A person who has 2 identical alleles of a particular gene.

Heterozygous

A person with 2 different alleles for a gene.

Genotype

Particular combination of alleles for a specific gene.

Phenotype

Appearance of a trait or health condition resulting from gene expression.

Dominant allele

Allele that masks expression of recessive allele in heterozygote.

Recessive allele

Allele that may be masked by a dominant gene.

Punnett Square

Table used to predict probabilities of genotypes in offspring.

Pedigree

Diagram showing family relationships, genotypes, and phenotypes.

Autosomal dominant disorder

Albinism is an example; affects the production of melanin pigment.

Aneuploidy

Cells that are not euploid; results from meiotic error.

Nondisjunction

When a chromosome pair fails to separate evenly during cell division.

Down syndrome

The most common autosomal aneuploid condition, caused by an extra chromosome 21.

Genetic Heterogeneity

Same phenotype that occurs from mutations in different genes.

Multifactorial traits

Traits affected by multiple factors including genes and environment.

Chromosomal Inheritance

Inheritance pattern involving entire chromosomes.

Sex-linked traits

Traits coded for by genes on sex chromosomes, mainly the X chromosome.

Incomplete penetrance

Some individuals do not express the phenotype despite having the genotype.

Variable expressivity

The manifestation of a phenotype varies among individuals.