Test your knowledge of the fundamental unit of life with these application-based questions.
Read the following scenario and answer the questions:
Scenario: A scientist is observing two different unknown tissue samples under a high-powered electron microscope.
Sample A cells possess a rigid, thick outer boundary, large empty-looking central sacs, and green oval structures.
Sample B cells have a flexible, thin outer boundary, small scattered sacs, and no green structures.
Q1. Identify the likely source of Sample A and Sample B (whether they belong to a plant or an animal). State two pieces of evidence from the observation that support your conclusion for Sample A.
Q2. The scientist notices that the cells in Sample B are actively changing their shape as they move. Why can the cells in Sample B do this, while the cells in Sample A cannot?
Q3. Imagine removing the nucleus from a living amoeba cell using a microscopic needle. What would be the immediate and long-term consequences for this cell?
Q4. Mitochondria are often called the "powerhouses" of the cell. If a person suffers from a genetic disorder where their mitochondria do not function correctly, what physical symptoms would they most likely experience in their daily life?
Directions: For the following questions, a statement of Assertion (A) is followed by a statement of Reason (R). Choose the correct option:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Q5.
Assertion (A): The cell membrane is called a selectively permeable membrane.
Reason (R): It allows only specific, useful substances to enter the cell while preventing harmful substances from passing through, and allows waste to exit.
Q6.
Assertion (A): Plant cells can survive without a vacuole.
Reason (R): The central vacuole in a plant cell stores water, sap, and waste products, and helps maintain the cell's turgidity (firmness).
Q7. Antibiotics like penicillin work by destroying the cell walls of bacteria, causing them to burst and die. Explain biologically why taking penicillin cures a bacterial infection in a human, but does not harm the human's own cells in the process.