Ellen began forgetting where she put her purse, how to balance a checkbook, and where she left the car in the parking lot. She is experiencing the signs and symptoms of:
Alzheimer's disease.
menopause.
menarche.
old age.

Alzheimer's disease

Explanation:

Alzheimer's disease occurs when there is a presence of abnormally structured  neurons and a reduced amount of acetylcholine in the regions of the brain involved in reason and memory. These neurons have fibrous proteins present in the form of bundles around the nucleus and amyloid plaques. Malfunctioning of these regions of the brain results in a gradual loss of reason with memory lapses. It makes the person unable to perform any type of daily activity. The given symptoms represent the fact that she is suffering from Alzheimer's disease

answer; ///i believe the answer your looking for is (ribosomes);

plato users:

d.  

there was a variety of food available on island x, but there were only large seeds and nuts on island y.