Genes for sex determination is:
**Core Concept**
The sex determination of an individual is primarily governed by the presence of specific sex chromosomes, which are X and Y. The interaction between these sex chromosomes and specific genes influences the development of male or female reproductive organs.
**Why the Correct Answer is Right**
The correct answer is based on the presence of the SRY gene on the Y chromosome, which is responsible for initiating the development of testes in the embryo. The SRY gene encodes a transcription factor that triggers the expression of other genes involved in testis development, ultimately leading to the formation of male reproductive organs. The presence of the SRY gene is crucial for the development of male sex characteristics, and its absence or mutation leads to sex reversal or other disorders of sex development.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the genes for sex determination are not solely controlled by the autosomal chromosomes. While autosomal genes can influence sex determination, the primary control is exerted by the sex chromosomes.
**Option B:** This option is incorrect because the gene for sex determination is not a single gene but a complex interplay of multiple genes and chromosomes.
**Clinical Pearl / High-Yield Fact**
The presence of the SRY gene on the Y chromosome is a critical factor in the development of testes and male sex characteristics. A mutation or deletion of the SRY gene can lead to sex reversal or disorders of sex development, emphasizing the importance of this gene in sex determination.
**Correct Answer: C. SRY gene on the Y chromosome**