CAST Practice: Cells and Life

​CAST Practice: Cells & Life

​What do you know about cell theory?

Multiple Choice

Students carried out an investigation in which they examined pond water under a light microscope. When they look at some green objects found in the pond water, they see detailed structures like the diagram.

Did this investigation produce evidence that this object is a living thing?

•  No; living things are large enough to be seen without a microscope.

• No; there is no mouth or digestive system.

• Yes; it is composed of cells

• Yes; it contains organized body systems.

​What do you know about a cell wall?

Multiple Select

Two students working on a model of a cell disagree about cell walls. One student says all cells have cell walls, and they help control the movement of substances into and out of the cell. The other student says that animals don’t have cell walls, and that cell walls are stiff, with the function of helping the cell hold its shape. Which of the following statements could be used by the students to develop an accurate model? Select all that apply

• Cell walls are found only in plants, fungi, bacteria, and some protists.

• Cell walls line the cell on the inside of the cell membrane.

• Cell walls manage the movement of all substances into and out of the cell.

• Cell walls often help the cell keep a rigid shape, especially in plants.

• Cell walls prevent viruses and harmful organisms from entering the cell.

​A student is given two slides containing samples and asked to examine them under the microscope during an investigation. They noticed that the two samples looked very different from one another. This is what the student sees.

​What do you notice?
What do you wonder?

Open Ended

Classify each of the samples as living or nonliving, and provide evidence to support your response.

Open Ended

Provide an explanation for the differences between the samples.

​A student used candy, frosting, and rice cakes to build a model of a cell.

I you were building a model of a cell using items from home or around the classroom, what would items would you choose to represent the different organelles?

Multiple Choice

Performance Task: In this performance task, you will apply your knowledge of cells and life. A student plans to build a physical model of a plant cell for a science project. The student is collecting available materials from the classroom and their home. They want to incorporate information about the function of the organelles and cell structures into a physical model, if possible. The first step is to decide on what to use for the outside of the cell, which will contain the rest of the cell material. The chosen material should demonstrate, if possible, the function as well as the form of the structure it models.

Which of the following is the best choice for the cell exterior?

• A cardboard box lined on the inside with a piece of cloth.

• A cardboard box lined on the inside with plastic wrap.

• A cardboard box with a piece of fabric wrapped around it.

• A hollow plastic ball that has been cut in half.

• A wooden box lined on the inside with some aluminum foil.

​Building a Model of a Cell

The student decides to represent the internal organelles of the cell by making shapes out of modeling clay. Where possible, they intend to press small items or pictures into the clay to illustrate how the organelles contributes to the overall function of the cell. Which of the following is the most accurate representation of the organelles listed?

Multiple Choice

The student decides to represent the internal organelles of the cell by making shapes out of modeling clay. Where possible, they intend to press small items or pictures into the clay to illustrate how the organelles contributes to the overall function of the cell. Which of the following is the most accurate representation of the organelles listed?

• Column J

• Column K

• Column L

• Column M