Answered

Discover new knowledge and insights with IDNLearn.com's extensive Q&A database. Find in-depth and trustworthy answers to all your questions from our experienced community members.

in roses, red is dominant over white. short stems are dominant over long stems. if you cross two heterozygous red, short-stemmed roses, what are the chances of producing the desirable trait of long-stemmed red roses?

Sagot :

LammettHashidn

Let

• R = red

• r = white

• S = short stem

• s = long stem

Then two heterozygous (RrSs) parents can each contribute one of the following allele pairs:

RS, Rs, rS, rs

so that the genotypes of their offspring have the following distribution:

[tex]\begin{array}{ccccc} & RS & Rs & rS & rs \\ RS & \boxed{RRSS} & \boxed{RRSs} & \boxed{RrSS} & \boxed{RrSs} \\ Rs & \boxed{RRSs} & RRss & \boxed{RrSs} & Rrss \\ rS & \boxed{RrSS} & \boxed{RrSs} & \boxed{rrSS} & \boxed{rrSs} \\ rs & \boxed{RrSs} & Rrss & \boxed{rrSs} & rrss \end{array}[/tex]

The probability of producing offspring with either the SS or Ss genotype is then 12/16 = 3/4.

In other words, there are 4² = 16 possible genotypes among the offspring, and each parent has a 1/2 probability of contributing the S allele. There are 2 cases to consider:

• both parents contribute the S allele with probability (1/2)² = 1/4

• one parent contributes the S allele while the other contributes the s allele, and this can happen in 2 ways with probability 2 × (1/2)² = 1/2

These events are mutually exclusive, so the total probability is 1/4 + 1/2 = 3/4.

We value your presence here. Keep sharing knowledge and helping others find the answers they need. This community is the perfect place to learn together. IDNLearn.com has the solutions to your questions. Thanks for stopping by, and see you next time for more reliable information.