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# Problem: In humans, dark hair (B) is dominant over blondness (b), and color blindness (c) is a sex-linked recessive trait. A women has a blond brother, a blond mother, and a dark-haired father. Her brother and her parents have normal vision. She bears the following three children by her blond, normal-visioned husband:a dark-haired son with normal vision,a dark-haired daughter with normal vision, anda dark-haired color-blind soni) Make a pedigree of the entire family showing the probable genotypes of all individuals.ii) What is the probability that her next (fourth) child will be a color-blind boy?iii) If her fourth child is a boy, what is the probability that he will have dark hair?iv) What is the chance that her next four children will all be girls?

###### Problem Details

In humans, dark hair (B) is dominant over blondness (b), and color blindness (c) is a sex-linked recessive trait. A women has a blond brother, a blond mother, and a dark-haired father. Her brother and her parents have normal vision. She bears the following three children by her blond, normal-visioned husband:

a dark-haired son with normal vision,

a dark-haired daughter with normal vision, and

a dark-haired color-blind son

i) Make a pedigree of the entire family showing the probable genotypes of all individuals.

ii) What is the probability that her next (fourth) child will be a color-blind boy?

iii) If her fourth child is a boy, what is the probability that he will have dark hair?

iv) What is the chance that her next four children will all be girls?

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Genetic Counseling concept. You can view video lessons to learn Genetic Counseling. Or if you need more Genetic Counseling practice, you can also practice Genetic Counseling practice problems.

What is the difficulty of this problem?

Our tutors rated the difficulty ofIn humans, dark hair (B) is dominant over blondness (b), and...as high difficulty.

How long does this problem take to solve?

Our expert Biology tutor, Kaitlyn took 19 minutes and 15 seconds to solve this problem. You can follow their steps in the video explanation above.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Herrick's class at UCONN.