4 - 4 Pedigree Analysis

Question 1

Pedigree Analysis

Answer 1

• A diagram that shows how traits are inherited from one generation to the next.
• A diagram tracing a particular trait through a family.
• They are used by genetic counselors to predict the likelihood of passing on a genetic disease.
• Ex: Sickle Cell Anemia, Downs Syndrome, and Cystic Fibrosis

Question 2

Drawing a Pedigree

Answer 2

• Generations are numbered with Roman numerals (I, II, III) on the left side of the pedigree.
• Print each person’s name or number neatly under their symbol.
• Children are put in age order from left to right if given, but may be rearranged to show special relationships. (ex: marriages)
• Provide a key for all symbols used.

Question 3

Male

Answer 3

Square

Question 4

Female

Answer 4

Circle

Question 5

Marriage

Answer 5

Horizontal line between couple

Question 6

Divorce

Answer 6

Broken horizontal line between couple

Question 7

Multiple marriages

Answer 7

Numbered horizontal line between couples

Question 8

Death

Answer 8

Diagonal slash over person’s symbol

Question 9

Siblings

Answer 9

Vertical line from parents to a bracketed horizontal line over siblings

Question 10

Fraternal twins

Answer 10

Connected by a triangular line above

Question 11

Identical twins

Answer 11

Connected by a triangular line above and a horizontal line between

Question 12

Adoption

Answer 12

Capital “A” inside symbol

Question 13

Having a trait

Answer 13

Shaded in as specified in your key