When this happens, the thyroid gland is no longer under pituitary control. The amount of hormone it produces is dependent on levels of TSI. TSI are the direct cause of hyperthyroidism in Gravesâ disease and various immune system chemicals known as cytokines also contribute to the symptoms that occur in this disorder.
Confidence votes 20. Female Iguanas will lay eggs when they become sexually mature, which is around 1.5 to 2 years old. They do not need to be fertilized to lay so therefore do not need a male Iguana. They need to be healthy before they lay or else there can be very serious problems.
Land iguanas are large â more than 3 feet long â with males weighing up to 30 pounds. They live in the drier areas of the Islands, and in the mornings can be found sprawled beneath the hot equatorial sun. To escape the heat of the midday sun, they seek the shade of cacti, rocks, trees or other vegetation.