Question

Antennae development in ants is thought to be a trait controlled by maternal effect. In ants, zig-zag coils are dominant to curly coils. Assume that a female develops zig-zag coils. What can be determined about inheritance of this trait in her family?
a. Her mother has zig-zag antennae.
b. Her brother has zig-zag antennae.
c. This female carries the zig-zag allele
d. This female's offspring will have zig-zag antennae.

Answer 1

Answer:

a. Her mother has zig-zag antennae.

b. Her brother has zig-zag antennae.

Explanation:

Available data:

• Antennae development ⇒ controlled by maternal effect
• Zig-zag coils are dominant
• Curly coils are recessive
• A female develops zig-zag coils

Maternal effect: Refers to the influence of the “environment provided by the mother” on the progeny phenotype. The mother´s genotype directly determines the progeny phenotype. Even though the progeny has a different genotype, it is irrelevant, as well as the father´s genotype or phenotype. This means that no matter what is the genotype of the offspring, all of them will express the same phenotype as their mother. The maternal effect is commonly seen in insects and might be seen in some mammals and plants.

So, if a female has zig-zag coils, this means that the mother also has zig-zag antennae and that all the brothers and sisters of this female ant have zig-zag antennae, independently of their genotype.

a. Her mother has zig-zag antennae ⇒ True. The trait is inherited from the mother.  

b. Her brother has zig-zag antennae ⇒ True. The whole progeny will express sig-zag antennae.

c. This female carries the zig-zag allele ⇒ Not necessarily.

d. This female's offspring will have zig-zag antennae ⇒ Depends on it´s genotype