Final answer:
The organelle responsible for producing steroid hormones such as testosterone and estrogen in the reproductive organs is the smooth endoplasmic reticulum. Specific cells, like Leydig cells in the testes and theca cells in the ovaries, conduct the synthesis of these hormones.
Step-by-step explanation:
In the reproductive organs, the organelle that produces the steroid hormones testosterone and estrogen is known as the smooth endoplasmic reticulum (SER). However, the specific cell types within the gonads—testes in males and ovaries in females—that are responsible for the synthesis of these hormones are the Leydig cells and the theca cells & granulosa cells, respectively. The testes are responsible for the production of testosterone, which is crucial for male secondary sex characteristics and reproduction functions, such as sperm production. The ovaries produce estrogen and progesterone, which regulate the female reproductive cycle and prepare the body for pregnancy. Leydig cells in men and theca cells in women synthesize steroid hormones from cholesterol within the SER, which then perform various functions key to human development and reproductive health.