Question

Drosophila has four homologous pairs of chromosomes. What is the number of linkage groups (homologous) in this animal?
A. Four
B. Two
C. Eight
D. Uncertain

Answer 1

Hint: Drosophila is a genus of flies, belonging to the family Drosophilidae who are commonly called as small fruit flies, pomace flies, vinegar flies or wine flies. The most common species of Drosophila is D. melanogaster and the entire genus contains almost 1500 species and is diverse in appearance, breeding, habitat and behavior. Drosophila are small flies basically pale yellow to reddish brown in color with red eyes. Developing brain structure in these flies make them the optimum candidate for neuro-genetic research.

Complete answer:
 The sperm cells of males are delivered to females in tangled coils and are the longest sperm cells of any studied organism on Earth. Drosophila species have wide reproductive capacity and some rare resources have ovaries that mature 10-20 eggs at a time and lay together on a site. The linkage is defined as the tendency of a gene located on the same chromosome to stay together in hereditary transmission. The genes which are located on the same chromosomes are called linked genes. The concept of linkage was put forward in 1910 by Thomas Hunt Morgan based on his experiment on D. melanogaster. It has four linkage groups which is the number of chromosomes that form the genome. The principle of linkage was discovered in 1906 by Bateson and Punnett in a sweet pea plant.

Hence, the correct option is A. Four.

Note: Drosophila species is extensively used as model organism in genetics, cell biology, biochemistry and developmental biology. The data of the genome is used for a variety of purposes including evolutionary genome comparison between various species.