The cuticle decreases water loss and stomata assist gas exchange. The plants from wet habitats must have a comparatively large number of stomata and thin cuticle. The plants existing in dry habitats must have comparatively few stomata and thick cuticle.
Answer;
Iodine
A diffuse, nontoxic goiter is usually due to a lack of Iodine in the diet.
Explanation;
-A diffuse non-toxic goiter is an enlargement of the thyroid gland without nodularity. It occurs in an endemic and sporadic distribution. It does not result from an inflammatory or neoplastic process and is not associated with abnormal thyroid function.
-Simple nontoxic goiter, which may be diffuse or nodular, is noncancerous hypertrophy of the thyroid without hyperthyroidism, hypothyroidism, or inflammation. Except in severe iodine deficiency, thyroid function is normal and patients are asymptomatic except for an obviously enlarged, non tender thyroid.
3D models are better than diagrams cause a diagram is flat, and its on a piece of paper, on the other hand 3D models have 3 Dimensions which show the model in a different view, they are also sometimes on paper but you have a better view if the model which helps you get more information of the diagram.
Hope I helped ya!! And plz put it under the right subject next time. This should go under Math.