Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: CHAPTER SUMMARY 37.1 Types of Hormones There are three basic types of hormones: lipid-derived, amino acid-derived, and peptide. Lipid-derived hormones are structurally similar to cholesterol and include steroid hormones such as estradiol and testosterone. Amino acid-derived hormones are relatively small molecules and include the adrenal hormones epinephrine and norepinephrine. Peptide hormones are polypeptide chains or proteins and include the pituitary hormones, antidiuretic hormone (vasopressin), and oxytocin. Answer: peptide
[EX A]: There are three basic types of hormones: lipid-derived, amino acid-derived, and what?

[EX Q]: Passage: In addition to having a plasma membrane, cytoplasm, a nucleus and ribosomes, eukaryotic cells also contain membrane-bound organelles . Each organelle in a eukaryote has a distinct function. Because of their complex level of organization, eukaryotic cells can carry out many more functions than prokaryotic cells. The main differences between prokaryotic and eukaryotic cells are shown in Figure below and listed in Table below . Keep in mind that some eukaryotic cells may have characteristics or features that other eukaryotic cells lack, such as the cell wall. Answer: eukaryotic cells
[EX A]: Which type of cell can carry out more functions, eukaryotic cells or prokaryotic cells?

[EX Q]: Passage: Red blood cells are shaped like flattened disks. There are trillions of red blood cells in your blood. Each red blood cell has millions of molecules of hemoglobin. Hemoglobin is a protein that contains iron. The iron in hemoglobin gives red blood cells their red color. It also explains how hemoglobin carries oxygen. The iron in hemoglobin binds with oxygen molecules so they can be carried by red blood cells. Answer: iron
[EX A]:
What in hemoglobin gives red blood cells their red color?