Complete linkage is observed in Male Drosophila sp.

Explanation:
Complete linkage refers to a type of genetic linkage where the genes controlling two different traits are located on the same chromosome and are very close to each other. In this type of linkage, the recombinants are completely absent, and the parental combinations are observed.

In the context of the given options, complete linkage is observed in Male Drosophila sp. This is because Drosophila is a well-studied model organism in genetics, and its inheritance patterns have been extensively studied. In Drosophila, the genes controlling different traits are located on different chromosomes. However, within each chromosome, there may be multiple genes that are closely linked.

In the case of Male Drosophila sp., complete linkage is observed because the genes controlling the specific traits being studied are located on the same chromosome, and there is no crossing over or recombination between them. This means that the traits will always be inherited together as a single unit, without any variation.

On the other hand, Female Drosophila sp. does not exhibit complete linkage because it has two X chromosomes. During meiosis, recombination can occur between homologous chromosomes, leading to the formation of recombinant gametes. Therefore, the traits controlled by genes on different chromosomes can show independent assortment and recombination.

Similarly, Female silkworm does not exhibit complete linkage because it also has multiple chromosomes, and recombination can occur during meiosis.

In conclusion, complete linkage is observed in Male Drosophila sp. due to the absence of recombination between closely linked genes on the same chromosome.

Ans a and c both are correct