B3 - Pedigree Charts

Last updated over 1 year ago

24 questions

Note from the author:

Instructions

B3 - Pedigree Charts

Last updated over 1 year ago

24 questions

Note from the author:

https://www.khanacademy.org/science/ap-biology/heredity/non-mendelian-genetics/a/hs-pedigrees-review

Instructions

https://www.khanacademy.org/science/ap-biology/heredity/non-mendelian-genetics/a/hs-pedigrees-review

Question 1

01:19

Question 2

01:23

Question 3

02:09

Question 4

02:27

Question 5

02:39

Question 6

02:47

Question 7

03:03

Question 8

03:21

Question 9

03:30

Questions 10 & 11

03:45

Question 12

04:01

Draggable item		Corresponding Item

Draggable item		Corresponding Item

Pedigrees are used to analyze the pattern of inheritance of a particular trait throughout a family. Pedigrees show the presence or absence of a trait as it relates to the relationship among parents, offspring, and siblings.

Pedigrees represent family members and relationships using symbols.

By analyzing a pedigree, we can determine genotypes, identify phenotypes, and predict how a trait will be passed on in the future. The information from a pedigree makes it possible to determine how certain alleles are inherited: whether they are dominant, recessive, autosomal, or sex-linked.

To start reading a pedigree:
Determine whether the trait is dominant or recessive. If the trait is dominant, one of the parents must have the trait. Dominant traits will not skip a generation. If the trait is recessive, neither parent is required to have the trait since they can be heterozygous.
Determine if the chart shows an autosomal or sex-linked (usually X-linked) trait. For example, in X-linked recessive traits, males are much more commonly affected than females. In autosomal traits, both males and females are equally likely to be affected (usually in equal proportions).

In this pedigree the recessive gene is "pimples on your back" represented by p. 
The dominant gene is "no pimples on your back" represented by P.

Answer the following questions.
A) How many kids did I-1 and I-2 have? _______
B) Which is a carrier of "pimples on their back", I-1 or I-2? _______ 
C) Which family member from generation 2 has "pimples on their back", II-1, II-2, II-3, or II-4? _______
D) Does the child in generation III have pimples on his back or not? _______ 

The diagram shows the inheritance of freckles in a family. The allele for freckles (F) is dominant to the allele for no freckles (f).

At the top of the pedigree is a grandmother (individual I-2) who has freckles. Two of her three children have the trait (individuals II-3 and II-5) and three of her grandchildren have the trait (individuals III-3, III-4, and III-5).

The diagram shows the inheritance of colorblindness in a family. Colorblindness is a recessive and X-linked trait Xb. 

The allele for normal vision is dominant and is represented by XB 

In generation I, neither parent has the trait, but one of their children (II-3) is colorblind. Because there are unaffected parents that have affected offspring, it can be assumed that the trait is recessive. In addition, the trait appears to affect males more than females (in this case, exclusively males are affected), suggesting that the trait may be X-linked.

Draggable item		Corresponding Item
Dominant allele		The genetic makeup of an organism (ex: TT)
Recessive allele		The physical characteristics of an organism (ex: tall)
Phenotype		Allele that is phenotypically expressed over another allele (it dominates it)
Genotype		Allele that is only expressed in absence of a dominant allele

Draggable item		Corresponding Item
Heterozygous		Having two identical alleles for a particular gene
Homozygous		Having two different alleles for a particular gene

B3 - Pedigree Charts

B3 - Pedigree Charts

Match the following terms with their meanings

Matche the following

What represents males on a pedigree?

What represents females on a pedigree?

Which is dominant?

Why is the male square shaded half way?

Why was the wife of the male shaded in her circle completely?

The first born male has a completely shaded square. What does that mean?

The daughter and son in law are shaded half way. What does that mean?

What is the most accurate depiction of the alleles for the grandkids?

Carries are heterozygous and have one dominant and one

A carrier is represented by a

Recessive genes are signified by

By analyzing a pedigree we can..

An affected male is represented by...

An affected female is represented by...

What is the genotype of individual I-2?

What is the genotype of individual III-2?