Can someone please help me with this question

Which is an example of a population?

Common symptoms of an iron-defiency anemia include muscle weakness shortness of breath and lightheadedness why does iron deficiency causes these symptoms

Which of the following is a feature of all cells? o a. all cells have a nucleus. o b. all cells have dna for at least part of their life cycle. het . o c. all cells are spheres. o d. all cells have a rigid cell wall.