Food is a basic need for all organisms
The correct terms to fill in the blanks would be contracts and dilates. In stressful situations, the sympathetic nervous system contracts the arteries of the circulatory system resulting to the dilation of the pupils of the eyes. Also, during these situations, the blood sugar levels are raised since the hormones for stress kick in to combat the stress which in turn raises the blood sugar.
The elements are pure forms of matter that cannot be broken down into simpler substances.
It is called haemogloblin.
Answer:
Homeostasis is defined as the state of body in which body maintains several chemical and physical changes inside the body affected by external factors.
Negative feedback loop includes a sensor, stimulus, control center, and effector which is used to control homeostasis.
A negative feedback loop is a reaction that reduce an excessive response and maintain the functions within the normal range. for example: if temperature and blood glucose level increases in the body, negative feedback loops control both the variables and maintain homeostasis.
Hence, negative feedback loops used to control body homeostasis.