mti_exam_key

# mti_exam_key - Biological Sciences 101 Dr. Mark Sanders...

This preview shows pages 1–2. Sign up to view the full content.

Biological Sciences 101 Dr. Mark Sanders Summer Session II 2008 Midterm I Exam Key 1a. (2) 5 = 32 phenotypic classes 1b. (1/2) 5 = 1/32 = .031 1c. (1/2) 2 (1/4) 3 = 1/256 = .0039 [Scoring: 2 pts answer, 2 pts work for each] 2a. The probability Marta is a carrier of galactosemia is ¼ (2 pts). Since Marta’s great grandmother was aa , Marta’s grandmother was Aa . There is a ½ chance the recessive allele was passed to Marta’s mother and another ½ chance the allele was passed to Marta. (1 pt). 2b. There is a 2/3 chance Paul is a carrier of galactosemia. Both of Paul’s parents are carriers, and since Paul is healthy and is not aa like his sister, his carrier probability is the 2/3 as determined by conditional probability. 2c. (1/4) (2/3) (1/4) = 1/24 = .042 2d. (23/24) 2 = (0.958) 2 = 0.918 2e. ¼. Having a child with galactosemia confirms that both Marta and Paul are carriers of the recessive allele. Each time they have a child there is a 1 in 4 chance the child will be homozygous recessive. [Scoring on 2b-e: 2 pts work, 1 pt answer or explanation]

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## mti_exam_key - Biological Sciences 101 Dr. Mark Sanders...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online