4) In a species of water strider, two alleles of one gene determine the characte

Question

4) In a species of water strider, two alleles of one gene determine the character difference o long versus short wings, and two alleles of a separate, independent gene determine t difference of green versus brown wing veins. The phenotype results for four separate (each involving different parents) are shown below. (Remember that these are matings among separate individuals and that the same phenotype can be produced by different genotypes.) the character Offspring Phenoty 294 0. Mating Parental Phenotypes long/brown long/green short/brown short/green 301 147 0 1long/brown x short/green 311 long/brown x short/brown 295 3long/green x short/brown 604 -4 | long/green x short/brown lisi 148 154 a) Using the letter L. for wing length and G for color, indicate which traits are dominant (uppercase) and which are recessive (lowercase). Dominant/Recessive? (cirele one wing length gene: long L short color gene: green brown G b) What are the genotypes of each parent in each cross? If more than one genotype is possible, list the alternative possibilities. (Remember that each mating involved a separate set of parents, so the 4 matings involved 8 separate parents in total). Genotype Phenotype of Genotype of Parent #2 Mating Phenotype long/brown1 2 long/brown 3 long/green 4 long/green | | Parent #2 short/green short/brown short/brown short/brown of Parent # 1 or Parent #1 THE NEXT QUESTION BEGINS ON THE NEXT PAGE

Explanation / Answer

ANSWER 4)
Long (L) > Short (l)
Long genotypes = LL, Ll, lL
Short genotypes = ll

Brown (G) > Green (g)
Brown genotypes = GG, Gg, gG
Green genotypes = gg

Answer a)
Since the 4 crosses show greater number of Longs and Browns, and hence these two become dominant traits while their counterparts are recessrive traits.

Answer b)
1. Since Long/Brown x Short/Green is giving Long/Brown : Long/Green :: 1 : 1
Hence, therefore,
Long/Brown has to be LLGg
Short/Green has to be llgg

2. Since Long/Brown x Short/Brown is giving Long/Brown : Short/Brown :: 1 : 1
Hence, therefore,
Long/Brown has to be LlGG or LlGg (provided other partner is not also Gg)
Short/Brown has to be llGG or llGg (provided other partner is not also Gg)

3. Since Long/Green x Short/Brown is giving all Long/Brown
Hence, therefore,
Long/Green has to be LLgg
Short/Brown has to be llGG

4. Since Long/Green x Short/Brown is giving all 4 outcomes in equal proportion
Hence, therefore,
Long/Green has to be LlGg
Short/Brown has to be llgg

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.