Select the odd one out w.r.t genic balance theory of sex-determination in Drosophila
(a) Y-chromosome plays no role in sex-determination
(b) Given by C.B . Bridges
(c) If X/A ratio is one, superfemales are produced
(d) If X/A ratio is less than 0.5, supermales are produced

Options

A. Y-chromosome plays no role in sex-determination
B. Given by C.B . Bridges
C. If X/A ratio is one, superfemales are produced
D. If X/A ratio is less than 0.5, supermales are produced

Answer

To solve the question regarding the odd one out with respect to the genic balance theory of sex determination in Drosophila, we will analyze each option step by step.

### Step 1: Understanding the Genic Balance Theory
The genic balance theory of sex determination, proposed by C.B. Bridges, states that the sex of an organism is determined by the ratio of X chromosomes to the number of sets of autosomes (A).

### Step 2: Analyzing Each Option
- **Option (a)**: "Y-chromosome plays no role in sex-determination."
- This statement is **incorrect**. According to the genic balance theory, the Y chromosome does not play a significant role in determining sex; it is primarily the X/A ratio that determines sex. Therefore, this option is a candidate for being the odd one out.

- **Option (b)**: "Given by C.B. Bridges."
- This statement is **correct**. The genic balance theory was indeed proposed by C.B. Bridges. This option cannot be the odd one out.

- **Option (c)**: "If X/A ratio is one, superfemales are produced."
- This statement is **incorrect**. An X/A ratio of 1 produces normal females, not superfemales. This option is also a candidate for being the odd one out.

- **Option (d)**: "If X/A ratio is less than 0.5, supermales are produced."
- This statement is **correct**. According to the theory, an X/A ratio of less than 0.5 results in the production of supermales. This option cannot be the odd one out.

### Step 3: Identifying the Odd One Out
From the analysis:
- Options (a) and (c) are both incorrect statements related to the genic balance theory.
- Therefore, both (a) and (c) can be considered odd ones out.

### Final Answer
The odd ones out with respect to the genic balance theory of sex determination in Drosophila are:
- (a) Y-chromosome plays no role in sex-determination.
- (c) If X/A ratio is one, superfemales are produced.