Lecture 17 - Genetic Variation & Disease #1 Flashcards
How much DNA do diploid organisms receive from each parent?
1/2
What is DNA packaged onto?
CHromosomes
What does each chromosome have?
a particular set of genes in a particular order
How many of each chromosome does a diploid organism have?
two of each chromosome (one from each parent)
Will the chromosomes from each parent be identical?
NO
What is an allele?
an alternative form of a genetic variant
What is the criteria for an allele?
The variation must be located on the same place in the gene
What could happen with differing alleles?
You could have two different versions of a protein
When can we track an inheritance pattern?
when a genetic variant causes a visible/measurable change in phenotype
What is the phenotype?
the observable characteristics or traits in an individual
What determines phenotype?
genotype - combination of alleles a person has for a a particular genetic variant
What is a dominant allele?
an organism with at least one dominant allele will show that alleles phenotype
What is a recessive allele?
An organism will only show a recessive allele when both alleles are the same
What does the mode of inheritance an allele has depend on?
What the allele does to the protein and how the protein functions
Are the modes of inheritance for gain of function and loss of function alleles usually the same?
No usually different
What does a gain of function allele do?
causes the protein to work too well or do something new
What does a loss of function allele do?
causes the protein to no longer work
What type of inheritance pattern will gain of function alleles often show?
Often dominant because it is hard to hide the gain in function
What type of inheritance pattern do loss of function alleles often show?
recessive - because usually the other allele can compensate for the lost function
What is a monogenic trait?
An inherited trait/characteristic that is controlled by a single gene
What type of inheritance pattern will monogenic traits often follow?
Simple dominant/recessive inheritance patterns
Does the environment influence monogenic traits?
Yes sometimes ie. no. of freckles you have
What is a polygenic trait?
An inherited trait/characteristic that is controlled by multiple genes