BS1050

Genetics

What is chromatin?

Contains DNA, Proteins, DNA metabolising enzymes, structural proteins. Ensures DNA is expressed properly

What is n in relation to the Genome?

n = number of chromosomes. There is no correlation between n and the complexity of an organism. 2n = diploid, 3n = triploid (only works in plants but results in no seeds)

What is c in relation to DNA content?

c = the amount of DNA in a haploid, unreplicated cell

What does homologous mean?

Gene copies related by descent, same gene in different species

What does Orthologous mean?

Pair of genes that are homologous and do the same job

What does paralogous mean?

pair of genes that are homologous but perform different jobs

What does analogous mean?

Genes that look the same (same sequence) but are not homologous

What is incomplete dominance?

When the heterozygous has a phenotype that is in between the phenotypes of the two homozygous, NOT codominance

What is a wild type allele?

the allele most commonly seen ‘in the wild’

What are examples of dominant mutations?

Huntingtons disease and achondroplasia (dwarfism)

What is epistasis?

gene interactions that affect the phenotype. (e.g. a gene can only be expressed if the other one is)

What is incomplete penetrance?

when the presence of a particular allele results in a defined phenotype in some but not all individuals

What is expressivity?

the extent in which a genotype is expressed in the phenotype (e.g. polydactyly can cause more than 6 fingers)