GED Science Practice Questions: Structure and Function of Living Cells

All life is composed of cells, which in turn act as building blocks for the specialized tissues and organs that make up our bodies. Although these cells perform many complex functions, you won’t need to know all the specific details when you take the GED Science test.

In the following practice questions, you start with a diagram or a passage of text, which contains all the information you’ll need to answer the question.

Practice questions

The first question refers to the following image of a human nerve cell.

1. The nerve cells in your body carry messages in the form of electrical signals. The signals travel from the cell body along the axon, which is protected by the

   

   The next question refers to the following passage.

   Cells Cells are the basic unit of all living things in the universe. Not only are flowers, weeds, and trees composed of cells, but you, your dog, and all other living things are also composed of cells. However, cells are different from organism to organism. That is why some plants produce roses and others produce dandelions and why some cells are in people and others in fish.

2. Which of the following is not composed of cells?

   A. dogs B. flowers C. granite D. forests

Answers and explanations

1. The correct answer is myelin sheath.

   You can see in the diagram that the axon is surrounded by the myelin sheath, a protective coating.

2. The correct answer is Choice (C).

   All the answer choices except granite are living substances that are made up of cells. Granite is an igneous rock, not a living substance.