Flipped Lesson 1 - Inheritance Patterns

Genome

All of the hereditary information that an organism has encoded in its DNA (or RNA for some viruses)

Chromosomes are made up of

DNA & protein (chromatin)

A ___ is a unit of heredity

Gene

Allele

Homozygous

Heterozygous

Phenotype is a result of what

Genetic makeup & environmental influences

Genotype

Traits/Character can be dichotomous - what does this mean

You either have it or you don’t - Yes/No

E.g. extra finger or presence/absence of a disease

Traits/Character can be quantitative/continuous - what does this mean

Not a simple/discrete yes/no property

Often involve a number of genes

E.g. Height/IQ

What are mendelian characters

Name a mendelian character

Presence of Huntington’s disease

Huntington’s disease gene map location

4p16.3

Is Huntington’s disease dominant or recessive

Dominant

Give an example of a mendelian trait which is recessive and disease causing

Cystic Fibrosis

Penetrance

Probability of a genotype being expressed. Yes/No

Incomplete penetrance

Is Huntington’s disease fully penetrative or does it have reduced penetrance

Fully penetrative

Name a disease with reduced penetrance

People with these genes are at high risk of developing breast cancer but aren’t guaranteed to get it

Expressivity

Difference between incomplete penetrance & variable expressivity

Incomplete dominance

Give an example of incomplete dominance

Example = achondroplasia