Sertoli cells have receptors for follicle stimulating hormone (FSH) and testosterone which are the main hormonal regulators of spermatogenesis. Hormones such as testosterone, FSH and luteinizing hormone (LH) are known to influence the germ cell fate. Their removal induces germ cell apoptosis.
In very basic terms, ISO is the level of sensitivity of your camera to available light. The lower the ISO number, the less sensitive it is to the light, while a higher ISO number increases the sensitivity of your camera. The component within your camera that can change sensitivity is called âimage sensorâ or simply âsensorâ.
ISO rating for Film Speed. ISO stand s for ' International Organization for Standardization ' and their film speed ratings are used to indicate the relative amount of light necessary to give a proper exposure. A normal film will be rated at ISO 100.