Question

1. which offspring could not arise from the parent cells with the chromosomes shown below? assume crossovers can occur between chromosome pairs in the parent cells.

allele key
dominant
c - curly wing
b - brown body
l - legs on head
r - red eyes
recessive
c - normal wing
b - black body
l - antenna
r - orange eyes
parent 1
parent 2
a
b
c
d
offspring a
offspring b
offspring c
offspring d

Explanation:

Step1: Identify parental allele sets

Parent 1: Chromosomes carry alleles $C, B, L, R$ (dominant) and $C, b, l, R$
Parent 2: Chromosomes carry alleles $c, B, L, r$ and $c, b, l, r$

Step2: Analyze possible allele combinations

All offspring must inherit one allele for each trait from each parent. For the eye color trait: Parent 1 only has $R$ (dominant red eyes), so all offspring will get $R$ from Parent 1, meaning no offspring can have recessive orange eyes ($rr$).

Step3: Match offspring traits to alleles

Offspring D has black body ($bb$) and orange eyes ($rr$). But Parent 1 cannot pass on $r$, so $rr$ is impossible.

Answer:

Offspring D