Genomics and Epigenetics Flashcards

Flashcards about Genomics and Epigenetics

Genome Size

The total number of nucleotides an organism has.

Gene Number

The total number of genes (sequences of nucleotides that code for a product).

Gene Density

The ratio of gene number to genome size.

Genomic Imprinting

Certain genes are expressed depending on which parent they are inherited from.

DNA Methylation

Stops gene expression by tightening chromatin organization of DNA without altering nucleotide sequence.

Temperature-Dependent Sex Determination

Gender is determined by the environmental temperature during a thermosensitive period of embryonic development.

Histone Acetylation

Increases gene expression by loosening chromatin organization of DNA, making it more accessible for transcription.

Prader-Willi Syndrome

A set of genes are only expressed on the father’s Chromosome 15, while the mother’s genes are imprinted. If the paternal genes are mutated, the child develops health conditions.

Angelman Syndrome

A set of genes is only expressed on the mother’s Chromosome 15, while the father’s genes are imprinted. If the maternal copies of the gene are deleted or mutated, health conditions result.

Queen Bees

The queen larva is fed a special diet of royal jelly that blocks DNA methylation, allowing for the expression of different genes, resulting in a different phenotype.

Epigenetics In Action

Epigenetic mechanisms like DNA methylation, histone acetylation, and non-coding RNAs are used to modify which hormone pathway gets expressed, leading to different sex organ development