Question

crosscutting concepts

1. connect to nature of science how is it that the cell theory can be designated as a scientific theory? based on what you learned in chapter 1, describe how the history of the cell theorys development is typical of the process of science.
2. structure and function why are cell walls useful in plant cells yet animal cells function well without them? describe another structure that is useful in either plant or animal cells but not in the other.
3. stability and change using figure 8 - 17, argue either against or in support of this statement: cells maintain homeostasis by minimizing the movement of molecules within and outside the cell.

Explanation:

1. The cell theory is a scientific theory as it is based on extensive observations and experiments by multiple scientists over time. Its development involved formulating hypotheses, testing them, and refining ideas, which is typical of the scientific process.
2. Plant cell walls provide rigidity and support, protecting against mechanical damage and helping maintain shape. Animal cells don't need them as they have other ways to maintain structure. Chloroplasts are useful in plant cells for photosynthesis but absent in animal cells.
3. Cells do not maintain homeostasis by minimizing molecule movement. They regulate the movement of molecules in and out through processes like diffusion, osmosis, and active transport to keep internal conditions stable. For example, they take in nutrients and expel waste.

Answer:

1. The cell theory is a scientific theory due to its basis in observation and experimentation, and its development follows the scientific process of hypothesis - testing and idea - refinement.
2. Plant cell walls offer rigidity and protection. Chloroplasts are in plant cells but not animal cells.
3. Cells maintain homeostasis by regulating, not minimizing, molecule movement through various transport processes.