Question

Pseudoalleles are
a. Two closely placed genes with nearly similar expression
b. Forms of the same allele
c. Mutations in different genes producing alleles with similar effect
d. Alleles producing a similar effect under changed conditions.

Answer 1

Hint: Pseudoalleles are the genes that are located close to each other, and similar in nature, and are genetically linked, which means that these two genes are nearly inherited together, and the functions are also nearly the same. So they appear to act as the same genes, hence they got the name Pseudoalleles.

Complete answer:
Characteristics of Pseudoalleles.
- Some hypothesis states that Pseudoalleles are formed as a result of gene duplication.
- These duplicated genes later can undergo the gene evolution, so that they develop new functions.
- In some cases of Pseudoalleles, the two genes can be separated or it can be recombined.
- Some of the characteristics of Pseudoalleles are, within the genes, they can cross over each other. And they can affect the same character.
- Even though they cross over, the recombination which generally occurs is very low frequency.

Example of pseudoalleles.
- Lozenge eye in drosophila is one of the examples of Pseudoalleles.
- Green and green had studied about the Lozenge eye in drosophila, where several alleles of the Lozenge gene are identified and Mapped together, and the mutant gene produces an eye with a glossy smooth surface.
- In drosophila, all heterozygous carrying two mutants were lozenge in phenotype.
- But the progeny of the heterozygous produce wild types of recombinants with a frequency higher than spontaneous mutations, indicating that those genes are Pseudoalleles.

Hence, the correct answer is option (A).

Note: Pseudoalleles, exhibit Cis-Trans position effect, in the case of trans heterozygous, mutants of Pseudoalleles produce the mutant Phenotype, while the pseudoalleles of Cis heterozygous produce the wild Phenotype. Another example of the Pseudoalleles is the Star asteroid eye in drosophila.