Pedigree Charts and Inheritance

Flashcards about pedigree charts and inheritance patterns, covering topics such as interpreting symbols, modes of inheritance, and identifying genotypes and phenotypes.

What do squares, circles, shading, and lines represent in pedigree charts?

Squares represent males, circles represent females. Shading indicates the presence of a specific trait. Lines indicate relationships and connections between individuals.

What is the purpose of using pedigree charts?

Pedigree charts can be used to observe patterns and predict the inheritance of traits within families, and to determine if a trait is dominant or recessive.

How are individuals and generations identified in a pedigree chart?

Each individual is numbered and each generation is labeled (I, II, III, etc.) in a pedigree chart to effectively communicate patterns.

Name some examples of X-linked recessive or dominant disorders.

Duchenne muscular dystrophy, Haemophilia A and B, Fragile X syndrome, and Alport syndrome.

Name some examples of autosomal dominant disorders.

Huntington's disease (HD) and Intestinal polyposis.

Name another example of a disorder with autosomal dominant inheritance.

Dwarfism.

Name some examples of autosomal recessive disorders.

Sickle-cell disease, Thalassaemia, and Cystic fibrosis.

What is an example of recessive inheritance?

A pedigree for red hair. Individual II2 and his partner do not have red hair but some of their children have it. They are both carrying the allele for red hair, but not expressing it.

What is an example of dominant inheritance?

A pedigree for tongue rolling. Individual II1 and her partner can roll their tongues and some of their offspring can and some cannot. The parents are both heterozygous for tongue rolling.

In the Rudolph’s red nose pedigree, which trait is dominant and which is recessive?

A reindeer with bright shiny noses have the recessive trait (n) and reindeer with the traditional black nose have the dominant trait (N).

What is a pedigree chart?

A diagram that shows a family’s relationships and how characteristics are passed on from one generation to the next.

Pedigree charts can be used to observe the mode of inheritance, including:

Autosomal dominant, autosomal recessive, X-linked dominant and X-linked recessive.