Question

Which of the following statements about Drosophila melanogaster (fruit fly) is incorrect in the context of its use in genetic experiments?

• A. It has a short 2-week life cycle
• B. Grows in complex rare medium
• C. Shows clear sex differentiation
• D. A single mating produces a large population

Hint:

Remember the major advantages of Drosophila: short life cycle, high fertility, easy maintenance, and distinct hereditary traits.

Answer 1

The Correct Option is B

Concept: Drosophila melanogaster, commonly known as the fruit fly, is one of the most extensively used model organisms in genetics. Scientists prefer this organism because it is easy to culture in laboratories, has a short life cycle, produces a large number of offspring, and exhibits clear hereditary traits. The pioneering genetic experiments conducted by Thomas Hunt Morgan on Drosophila helped establish the chromosomal theory of inheritance. To identify the incorrect statement, we must examine each option carefully.

Step 1: Analysis of Option (A)
Fruit flies complete their life cycle in approximately 10--14 days under suitable laboratory conditions. This short generation time allows researchers to study multiple generations within a relatively short period. Therefore, this statement is correct.

Step 2: Analysis of Option (B)
One of the major advantages of using Drosophila is that it can be easily grown on a simple and inexpensive culture medium consisting of materials such as banana, yeast, cornmeal, and agar. The statement that it grows in a “complex rare medium” is incorrect because no specialized or rare growth medium is required. Therefore, Option (B) is the incorrect statement.

Step 3: Analysis of Option (C)
Male and female fruit flies exhibit clear sexual dimorphism. Males are generally smaller and possess darker posterior abdominal segments, whereas females are larger with pointed abdomens. Thus, this statement is correct.

Step 4: Analysis of Option (D)
A single mating can produce hundreds of offspring. This large progeny size helps geneticists study inheritance patterns with statistical reliability. Therefore, this statement is also correct. Conclusion: Among all the given options, only Option (B) is incorrect. \[ \boxed{\text{(B) Grows in complex rare medium}} \]