1. In the nematode Caenorhabditis elegans, d (dumpy), u (uncoordinated, and (kno

Question

1. In the nematode Caenorhabditis elegans, d (dumpy), u (uncoordinated, and (knobby) are recessive genes located on the same chromosome. Females normal for all three traits were mated with dumpy, uncoordinated, knobby males and the following progeny were observed: Phenotypes Number Dumpy, uncoordinated, knobby Uncoordinated, knobby 392 Knobby 34 Uncoordinated 61 Dumpy, uncoordinated 32, Dumpy, knobby Dumpy Wildtype tester d a) What were the genotypes of the crosses (P generation an generation)? (5 pts.) i. why was the trihybrid F1 female mated with dumpy, uncoordinated, knobby males? (This is not a reality TV show. ii. What must be the genotype of the F2 offspring that are uncoordinated? That are dumpy, knobby? iii. If you got these, then write out the gametotypes based on the F1 mother's gametes for all offspring. iv. the haplotypes in complementary pairs. Each pair Arrange should have two alleles at each of the three loci between them. Each haplotype in a pair should have approximately the same numbers. Did you get it right? v. Which haplotypes are the parental? vi. You know that the original parents are homozygous. (Why?) Write out the parental cross. Write out the F1 x Tester cross.

Explanation / Answer

a) The genotypes of the crosses are -

Heterozygous females - DdUuKk

Recessive trait - dduukk

i) the trihybrid F1 was mated with the recessive dumpy, uncoordinated, knobby males because . This test is called the test cross in which the recessive trait is mated with the wild type to know The homozygousity or heterozygosity of the F1.

ii) genotype of F2 having

- uncoordinated phenotype is ddUUkk

- dumpy phenotype is DDuukk

- knobby is dduuKK

V) the parental haplotypes are :

- dduukk and DDUUKK.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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