Answer:
Option A
Explanation:
Thyroid is primarily caused by lack of iodine but there are other reasons as well that lead to increased size of the thyroid gland. Some of these reason is
a) over- or underproduction of thyroid hormones
b) Nodules in the glans
Some times, due to overstimulation immune system itself attack the thyroid gland thereby producing excess thyroxine and hence causing the thyroid to swell
Thus, Option A is correct
The right answer is c. 3 to 10 million
The latest estimates are a bit more precise: there are 8.7 million living species (which is included in the range between 3 and 10 million), 6.5 million on land and 2.2 million in the water. Which is amazing, since there is more sea than land on our planet.
Researchers estimate that there are 7.77 million animal species, only 298,000 plant species and 611,000 species of fungi and molds.
study suggests that photosynthetic eukaryotes may have emerged around 1.9 billion years ago in freshwater habitats. Eukaryotes are thought to have evolved the capacity for photosynthesis through a process called endosymbiosis, in which a protist host encapsulated a photosynthetic cyanobacterium.
