Chapter 4 - genetics

Genetic linkage

Refers to the tendency of certain genes to be inherited together because they are located near each other on the same chromosome.

Parental

The term used to describe offspring that inherit a combination of alleles that are the same as one of the parents.

Recombinant

Offspring that have inherited a new combination of alleles different from that of the parents due to crossing over during meiosis.

Map unit

A unit of measurement in genetics that corresponds to a 1% chance of recombination occurring between two genes.

centiMorgan

Another unit of genetic distance equal to 1% recombination frequency.

SCO = single crossover

A genetic event during meiosis where a single crossover occurs between homologous chromosomes.

DCO = double crossover

A genetic event during meiosis where two crossovers occur between homologous chromosomes.

RNA interference

A biological process where RNA molecules inhibit gene expression or translation.

siRNA = small interfering RNA

Small RNA molecules that can trigger the degradation of specific mRNAs.

microRNA = miRNA

Small non-coding RNA molecules that regulate gene expression post-transcriptionally.

DICER

An enzyme involved in the processing of double-stranded RNA into small RNA molecules.

RISC complex

RNA-induced silencing complex, which is involved in the regulation of gene expression by small RNAs.

CRISPR array

Clustered Regularly Interspaced Short Palindromic Repeats, a genetic locus containing short, repetitive DNA sequences.

Cas proteins

CRISPR-associated proteins that are involved in the CRISPR-Cas immune system in bacteria and archaea.

Cas9

A type of Cas protein commonly used in CRISPR gene editing technology.

Cas nuclease

The enzymatic activity of Cas proteins that can cut DNA at specific target sequences.

Guide RNA

RNA molecules that direct the Cas nuclease to specific target sequences for gene editing.

sgRNA = single guide RNA

A synthetic RNA molecule used in CRISPR gene editing as a simplified version of guide RNA.