The answer to Question 23 will be different if R and T are very far apart on their chromosome (and if that is true, then automatically r and t will also be very far apart on their chromosome). If it undergoes meiosis, there are four genotypes that can be produced, not just two. Why? What are the four genotypes? Which represent recombinant chromosomes? Which represent parental chromosomes? Look at Figure 16-18 for help if you need it.

Figure 16-18

Question 23

We say that genes that are close together on the same chromosome are linked. What does that mean? Imagine that in a diploid nucleus, one chromosome has the allele R and right next to it on the same chromosome is the allele T for a different gene. Are these linked? Imagine that r is right next to t on the homologous chromosome. If this cell never undergoes meiosis, does this matter at all? If it does undergo meiosis, what are the two genotypes that the gametes are most likely to have? Look at Figure 16-17 for help if you need it.

Figure 16-17

Transcribed Image Text:

Meiosis (A) SY (B) 50% S1 Two possible Ss Yy individuals 50% or S ST Test parent: SsYy, S linked to Y, s linked to y Possible gametes (no crossing over): 50% SY, 50% sy 50% Types of gametes if no crossing over occurs st 50% Double homozygous recessive parent: ssyy Phenotype: wrinkled, green Possible gametes: 100% sy sy 100% SY 50% 50% SsYy smooth yellow ssyy Meiosis sy 50% 50% wrinkled green