Genetics Exam 3

Paralogs are…

DNA sequences that are similar to one another due to duplication.

functional redundancy

two identical genomic loci that have the same function causing immediate gain of function

solution to functional redundancy

Ohno’s Model and the DDC Model

Ohno’s Model has three fates:

neofunctionalization, pseudofunctionalization, retention of same ancestral function

DDC Model

Duplication Degeneration Complementary model

DDC leads to…

subfunctionalization

3 types of RNA produced during transcription and the specific polymerases

1. RNA polymerase I transcribes ribosomal RNA (rRNA) genes.

2. RNA polymerase II transcribes all structural genes (mRNA).

3. RNA polymerase III transcribes transfer RNA (tRNA) and the 5S RNA genes.

RNA polymerase I

transcribes ribosomal RNA (rRNA) genes

RNA polymerase II

transcribes all structural genes (mRNA).

RNA polymerase III

transcribes transfer RNA (tRNA) and the 5S RNA genes.

Central Dogma

How many Hox genes do humans have?

39

Hox clusters exhibit which two types of collinearity

temporal and spatial collinearity

Spatial Colinearity

Hox gene position in cluster matches relative position of Hox transcription/expression along

the primary Anterior-posterior axis.

Temporal collinearity

position of a Hox gene in the cluster determines timing of expression in

embryonic life.

processed pseudogene

mRNA molecules reverse transcribed by a special reverse transcription

polymerase, forming double stranded RNA/DNA hybrid that cannot be translated and can

integrate anywhere in the genome.

The wobble rule

The first codon of any protein in any organism is ‘AUG’. The tRNA with an anticodon ‘UAC’ carries the amino acid Methionine. Thus the first amino acid of any protein in any organism is Methionine. The start codon (AUG) defines the beginning of the open reading frame (ORF), a sequence of codons that defines the sequence of the polypeptide.

Exon skipping

spliceosome removes exon along with introns during mRNA splicing causing exon to be left out of final mRNA transcript

Cis mutation

A genetic alteration on the same DNA, chromosome, gene as the gene it affects

Trans mutation

Concept describing the evolutionary change of species into another

Pseudogenization

Paralog accumulates a LOF mutations eg deletion, nonsense,etc that makes it nonfunctional

Neofunctionalization

The extra paralog that is freed from constraints takes on a new function by cis and/or trans mutations

Retention of ancestral function

The second pardlog retains the same ancestral function.

The production of gene families, such as the goblin genes, is the result of

gene duplication

homologous genes with in a single species are said to be

paralogs

Activator proteins bind to what type of DNA sequence

enhancers

What is the result when the core histones are acetylated via histone acexyltransferase

The DNA becomes less associated with the core

Combination control of transcription factors refers to …

The combination of many factors determines the expression of any given

splicing joins together

two exons