*Question*
Q: Models may be physical, conceptual, or what else? Read this paragraph and choose the correct option from the provided answers: Models may be physical, conceptual, or mathematical. Choices: - experimental - fundamental - theoretical - mathematical A:
**Answer**
mathematical

*Question*
Q: What decides what may enter or leave a cell? Read this paragraph and choose the correct option from the provided answers: The cell membrane also decides what may enter or leave a cell. The membrane is said to be semipermeable or selectively permeable, allowing only certain ions and organic molecules to cross the membrane. The plasma membrane contain many proteins, as well as other lipids called sterols. The proteins have various functions, such as channels (channel proteins) that allow certain molecules into the cell, and receptors (receptor proteins) that bind to signal molecules. In Figure above , the smaller (green) molecules shown between the phospholipids are cholesterol molecules. Cholesterol helps keep the plasma membrane firm and stable over a wide range of temperatures. At least ten different types of lipids are commonly found in plasma membranes. Each type of cell or organelle will have a different percentage of each lipid, protein and carbohydrate. Choices: - nucleus - cell wall - golgi apparatus - cell membrane A:
**Answer**
cell membrane

*Question*
Q: What term is used to describe the line of latitude right in the middle of the planet? Read this paragraph and choose the correct option from the provided answers: Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. Choices: - Prime Meridian - orbital - pole - equator A:
**Answer**
equator

*Question*
Q: Maintaining a high metabolic rate takes a lot of what? Read this paragraph and choose the correct option from the provided answers: Maintaining a high metabolic rate takes a lot of energy. The energy must come from food. Therefore, mammals need a nutritious and plentiful diet. The diets of mammals are diverse. Except for leaf litter and wood, almost any kind of organic matter may be eaten by mammals. Choices: - food - calories - fuel - energy A:
**Answer**
energy