Cellular Control Systems Test

Homeostasis, Feedback Mechanisms & the Cell Cycle

Name:

Date:

🔬 Part 1: Multiple Choice

Circle the best answer for each question.

1. Which type of feedback mechanism is responsible for maintaining a stable body temperature of approximately 98.6°F?

A) Positive feedback

B) Negative feedback

C) Neutral feedback

D) Cascade feedback

2. Which of the following is an example of a positive feedback mechanism?

A) Blood glucose regulation by insulin

B) Thermoregulation during fever

C) Uterine contractions intensifying during childbirth

D) Pupil constriction in bright light

3. During which phase of the cell cycle does DNA replication occur?

A) G1 phase

B) S phase

C) G2 phase

D) M phase

4. What is the correct sequence of genetic information flow in a cell?

A) RNA → DNA → Protein

B) Protein → DNA → RNA

C) DNA → RNA → Protein

D) DNA → Protein → RNA

5. A cell that skips the G1 checkpoint and divides uncontrollably is most likely exhibiting characteristics of:

A) Apoptosis

B) Meiosis

C) Cancer

D) Differentiation

✏️ Part 2: Short Answer

Answer each question using complete sentences.

6. Define homeostasis and explain why it is essential for the survival of an organism.

7. Compare and contrast negative feedback and positive feedback. Give one real-world body example of each.

8. Explain the role of checkpoints in the cell cycle. What could happen if a checkpoint fails to function properly?

🖊️ Part 3: Diagram & Application

9. Label the Feedback Loop: In the box below, draw and label a negative feedback loop using blood glucose regulation as your example. Include: stimulus, receptor, control center, effector, and response.

10. Select ALL steps that are part of the Central Dogma of Molecular Biology:

Transcription (DNA → mRNA)

Translation (mRNA → Protein)

Replication (DNA → DNA)

Glycolysis (Glucose → Pyruvate)

Reverse Transcription (RNA → DNA)

11. Fill in the blanks using the word bank below.

Word Bank: effector | receptor | stimulus | set point | response

In a homeostatic feedback loop, a change in the environment is called a _________________. A _________________ detects this change and sends a signal to the control center. The control center compares the information to the _________________ and activates an _________________, which produces a _________________ to restore balance.

12. Critical Thinking: A patient's body temperature rises to 104°F. Describe two specific physiological responses the body would use to bring the temperature back to normal (98.6°F), and identify what type of feedback mechanism is involved.