3.14 - Monohybrid Inheritance and Genetic Diagrams Flashcards
What do family trees show?
Family trees show the inheritance of different phenotypes over generations in the same family.
What is a monohybrid cross?
A monohybrid cross looks at the probability of the offspring of two parents having certain genotypes and phenotypes.
How is a monohybrid cross performed?
This is done using the alleles the two parents have for a gene and a Punnett square diagram.
What do uppercase letters represent in genetics?
Uppercase letters are used to represent dominant characteristics.
What do lowercase letters represent in genetics?
Lowercase letters represent recessive characteristics.
Which letters are commonly used to represent alleles?
You can choose any letter but usually either A or B is used for simplicity.
What is the chance of having an offspring who is homozygous dominant?
Combining the alleles results in a 1/4 chance of having an offspring who is homozygous dominant (BB, or has two dominant alleles).
Uppercase letters are used to represent dominant characteristics. Lowercase letters represent recessive characteristics. You can choose any letter but usually either A or B is used for simplicity. Notice that combining the alleles shown above results in 1⁄4 chance of having an offspring who is homozygous dominant (BB, or has two dominant alleles),
What is the chance of having a homozygous recessive offspring if both parents have the allele?
There is no chance of having a homozygous recessive offspring.
What determines whether Bb (heterozygous recessive) offspring show symptoms?
It depends on whether the condition is recessive or dominant.
What are family pedigrees used for?
Family pedigrees are used to show how a condition (or the allele causing it) is passed down through generations.
How do family pedigrees help in understanding genetic patterns?
They help to better visualize certain patterns, such as how recessive alleles normally ‘skip a generation’.
What shape represents males in a lineage?
Squares represent males.
What shape represents females in a lineage?
Circles represent females.
What do black shapes represent in a lineage?
Black shapes represent an affected individual.
What do white shapes represent in a lineage?
White shapes represent an unaffected individual.
What does a line through a shape indicate?
A line through the shape means that the individual is deceased.
What does a line passing directly between two shapes signify?
A line passing directly between two shapes means that the two are partners.
What does a line overhanging a group of individuals indicate?
A line overhanging a group of individuals means that they are siblings.
