a little genetics review
TRANSCRIPT
A Little Genetics Review
1. A pink elephant is mated with a blue oneand all the offspring are pink with bluespots! This is an example of
A. normal inheritanceB. codominanceC. incomplete domianceD. a sex-linked trait
1. A pink elephant is mated with a blue oneand all the offspring are pink with bluespots! This is an example of
A. normal inheritanceB. codominanceC. incomplete domianceD. a sex-linked trait
2. A dark gray chinchilla is crossed with alight gray chinchilla and there are lightgray offspring and dark gray offspring.This is because of
A. normal inheritance.B. codominance.C. incomplete dominance.D. sex-linked inheritance.
2. A dark gray chinchilla is crossed with alight gray chinchilla and there are lightgray offspring and dark grey offspring.This is because of
A. normal inheritance.B. codominance.C. incomplete dominance.D. sex-linked inheritance.
3. A normal woman and a normal man have fivechildren, 4 boys and one girl. The girl and one ofthe boys are normal, the other three boys haveflippitis (the uncontrolled flipping of channelswith the remote). Flippitis is caused by:
A. normal inheritance.B. codominance.C. incomplete dominance.D. sex-linked inheritance.
3. A normal woman and a normal man have fivechildren, 4 boys and one girl. The girl and one ofthe boys are normal, the other three boys haveflippitis (the uncontrolled flipping of channelswith the remote). Flippitis is caused by:
A. normal inheritance.B. codominance.C. incomplete dominance.D. sex-linked inheritance.
4. Back to the chinchillas … If one parent isdark gray and the other is light gray, whatpercentage of their offspring will be lightgray? How many will be dark gray?
A. 50% light gray; 50% dark grayB. 25% light gray; 75% dark grayC. 75% light gray; 25% dark gray
* How do you know?
4. Back to the chinchillas … If one parent is darkgray and the other is light gray, what percentageof their offspring will be light gray? How manywill be dark gray?
A. 50% light gray; 50% dark grayB. 25% light gray; 75% dark grayC. 75% light gray; 25% dark gray
* How do you know?
Here’s why…DD, Dd = dark gray dd = light gray
Dark gray X Light gray Dd dd
Geno: 2 Dd : 2 dd
Pheno: 2 Dark gray: 2 Light grayddDdd
ddDdd
dD
5. A normal man and a normal woman are planning to havea family but they are concerned because the man’sbrother has hemophilia (a disorder whose gene islocated on the X chromosome). There is no history of thedisease in the woman’s family. What are their chances ofhaving any children with the disorder?
A. 50%B. 25%C. 100%D. 0%
How do you know?
5. A normal man and a normal woman are planning to havea family but they are concerned because the man’sbrother has hemophilia (a disorder whose gene islocated on the X chromosome). There is no history of thedisease in the woman’s family. What are their chances ofhaving any children with the disorder?
A. 50%B. 25%C. 100%D. 0%
How do you know?
• Here’s whyNormal ♀ X Normal ♂
XNXN X XNY
Geno: 2 XNXN :2 XNY
Pheno: 2 normal ♀: 2 normal ♂XNYXNYY
XNXNXNXNXN
XNXN
6. More elephants…If two spotted elephantswere mated what types of offspring wouldyou expect and in what ratio?
A. 100% spottedB. 25% spotted; 50% blue; 25% pinkC. 50% pink; 50% blueD. 50% spotted; 25% pink; 25% blue
Be able to explain your answer.
6. More elephants…If two spotted elephantswere mated what types of offspring wouldyou expect and in what ratio?
A. 100% spottedB. 25% spotted; 50% blue; 25% pinkC. 50% pink; 50% blueD. 50% spotted; 25% pink; 25% blue
Be able to explain your answer.
Here’s why…EPEP = pink EPEB = spotted EBEB = blue
Spotted X Spotted EPEB EPEB
Geno: 1 EBEB: 2EBEP: 1EPEP
Pheno: 1 Blue: 2 Spotted: 1 Pink
EBEBEPEBEB
EPEBEPEPEP
EBEP