Answer:
Iodine
Explanation:
Iodine is needed by animals because the body's metabolic rate is controlled by the action of an iodine hormone, called thyroxine, which is secreted by the thyroid gland in the neck.
If the animal fails to supply enough iodine through food to be able to make a normal amount of this compound, then the thyroid gland enlarges or expands trying to create enough, resulting in a common type of goiter.
Gaurd cells are high for exchange of gad
The best way to do a observation can be a microscope or by taking notes ,and by , taking pictures or, asking questions about the subject that you and the teacher or you, your teacher and the class is talking about .! Hope this helps ..
<span>(According to Reference)
Whereas an onion epidermal cell has a cell wall, a human cheek cell does not. Instead, a semi-permeable membrane surrounds the cytoplasm of the cheek cell. While there are chloroplasts present in onion cells, they are absent in cheek cells. </span>
The correct option is C.
Obligate anaerobes are micro organisms that are poisoned and killed when exposed to the normal atmospheric oxygen concentration. These organisms can only survive in the absences of oxygen, therefore, they carry out only anaerobic form of respiration in order to obtain the energy that they need. <span />