## Rajp98 3 years ago In a monohybrid cross, if the gene for tall (T) plants was incompletely dominant over the gene for short (t) plants, what would be the predicted result of crossing two intermediate (Tt) parent plants? (Hint: You may want to complete a Punnett square.) A. 25% tall, 50% intermediate, 25% short B. 25% tall, 75% intermediate C. 50% tall, 25% intermediate, 25% short D. 100% intermediate

1. Rajp98

i set up a punnet square, but still dont get it

2. yukitou

|dw:1339804224049:dw| 1 TT : 2 Tt :1tt 1 tall: 2 intermediate : one short i hope this helps.

3. Rajp98

thanks so much!

4. Rajp98

know this one--?? In guinea pigs, dark hair (D) is dominant over light hair (d) and curly hair (C) is dominant over smooth hair (c). Complete a dihybrid cross for parents with the genotypes: DdCc × DdCc and answer the following in complete sentences. Describe how you would set up a Punnett square for this cross. List the likelihood of each possible offspring genotype. List the likelihood of each possible offspring phenotype.

5. Rajp98

been trying it for a while but i just cant make a good sqaure for it

6. Rajp98

7. yukitou

|dw:1339804784081:dw| If you have a parent genotype which is DdCc, the possible gametes is DC, Dc, dC and dc (4 different combinations). When you cross these 4 posibles choices of gametes with another 4 possible gametes, you have 9 different genotype and 4 different phenotype.

8. yukitou

You can take your time to cross the allele and group the phenotype and genotype.

9. Rajp98

K i crossed em

10. Rajp98

now?

11. Rajp98

is the likelihood of each possible offspring genotype 25%, and the likelihood of a possible phenotype 75%??

12. Rajp98

i think im right

13. Rajp98

Yukitou, can you help =(

14. yukitou

which one? Usually in dihybrid cross, the phenotype ratio is 9:3:3:1 where 9 is D-/C-, 3 is dd/C-, another 3 is D-/cc and the 1 is dd/cc. D and C are dominant allele, d and c are recessive. The dash can be either the dominant or recessive allele because their 'partner' allele is dominant. is the likelihood of each possible offspring genotype 25%, and the likelihood of a possible phenotype 75%?? You're right but the percentages might change depends on situation. You can have DD/CC (which is one out of sixteen genotypes) but the phenotype by this DD/CC is 9 out of 16 because of D and C dominant alleles and there are also DDCc, DdCC and DdCc contributes to this 9/16 ratio.

15. Rajp98

no i mean answering- List the likelihood of each possible offspring genotype. List the likelihood of each possible offspring phenotype.

16. Rajp98

Do you get it ???

17. Rajp98

I answered the first quetion, about setting up the square, now I need the last 2- List the likelihood of each possible offspring genotype. List the likelihood of each possible offspring phenotype.

18. Rajp98

19. yukitou

ok.... If you cross DC and DC, you get DDCC. If cross dc and dc, you get ddcc. You repeat the same thing for others combinations. possible genotype: 1 DDCC, 1 DDcc, 1 ddcc, 1ddCC, 2 DDCc, 2 DdCc, 4 DdCC, 2 ddCc, 2 Ddcc possible phenotype: 9 dark and curly, 3 light and curly, 3 dark and smooth, 1 light and smooth

20. Rajp98

Thank you for all your help. You are a lifesaver, tommorow i will find out result. May God Bless your Grave Son.,

21. yukitou

no problem. This is a learning process for me too :D