Part 1. Norrie disease is caused by a recessive mutation on the X chromosome in a gene called norrin. The disease affects the eyes and can cause blindness. In the picture below, the left (A) and right (B) retinas from the same female mouse are shown. The X chromosome inherited from the father is labeled magenta and the X chromosome inherited from the mother is labeled yellow. A. B. From this picture, and the information you know about X chromosomes, what can you conclude? Imprinting randomly renders one of these X chromosomes inactive per cell, so this is what you would expect from that process. The maternal chromosome is likely imprinted in the left eye while the paternal chromosome is likely imprinted in the right eye. In the left eye, more of the cells have the paternal chromosome inactivated than in the right eye. In the left eye, more of the cells have the maternal chromosome inactivated than in the right eye.

STUDY GUIDE Name a A HUMAN TRAITS In your textbook, read about color blindness in Section 27:2. 1. Color blindness is a trait carried on the sex chromosomes. Let C be normal color vision and c b red-green color blindness. Use the diagrams to answer the questions. a. What is the sex of each of these people? Write either male or female on the blank below each. XX XX X Xa XX C b. Which are red-green color blind? c. Which have normal color vision? X X XXXXX B ①① X X XXXXX M a XaXa Date a d. Which has normal color vision even with the gene for color blindness? 2. a. Complete the following Punnett squares. The first one has been done for you. b. Using these colors, shade the following parts of the Punnett squares. Blue-normal females Yellow-normal males Red-color blind females Green-color blind males X X XXXXX Class D CHAPTER 27 X X XXXXX a Xalo E X X X×××× X oooolgolma 8 X X XXXXX a X a Xa 15 1

5. In German Shepherd dogs, hair length and hip dyslpasia are determined by two different genes located on different chromosomes. In answering the following questions, use the letters D and d for fur length and H and h for hip dysplasia. Max, a long-haired dog with no hip dysplasia, was bred with Rin, a short-haired dog that was later found to have hip dysplasia. All of their children had long hair and hip dysplasia. a. Give the genotypes of the following: Мах Rin Their children (the F,) Buddy is a German Shepherd dog with short hair and was heterozygous for having hip dysplasia. b. What is Buddy's genotype? c. Give the genotypes of all of the gametes Buddy could produce.

Question:- A female fruit fly that is heterozygous for the white-eye mutation has red-eyed sons and white-eyed sons in equal proportions:   a. regardless of the genotype of the male.   b. only when mated with a red-eyed male.   c. only when mated with a white-eyed male.   d. only when mated with a heterozygous male.

pls answer only item no. 7, 8, and 9. thank u in advancee!

2) In humans, one X chromosome in females is inactivated. Why does a female with one X chromosome show Turner syndrome? What is the difference between two X chromosomes with one X inactivated and one X chromosome in a female?

Can someone help with this question?

Color blindness in humans is an X-linked recessive trait. This means that... O a. Females are more likely to be color blind than males b. The gene associated with color blindness is found on the X chromosome, and an individual must have one (in males) or two (in females) mutant copies of the allele in order to be diagnosed as being color blind