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.
Iguanas are reptiles and nearly all reptiles lay eggs. There are some reptiles that do not lay eggs, but they are very rare. Female iguanas usually lay a clutch of eggs every year once they're mature. If there is no male iguana, she will still lay eggs, but they won't be fertile.
On average, pullets, or juvenile hens, start laying eggs at about 6 months of age, depending on the breed. Larger, heavier birds like Wyandottes, Plymouth Rocks and Orpingtons will lay on the later side whereas lighter, smaller breeds like Leghorns, Stars, and Australorps will start laying sooner.