1. Centrioles are structures involved in cell division. What is their specific role?

A. Forming the nuclear envelope
B. Replicating DNA
C. Organizing microtubules during cell division
D. Protein synthesis

Correct answer: C

Rationale: Centrioles are cylindrical structures found in animal cells that play a crucial role in organizing microtubules during cell division. They form the spindle fibers that help separate chromosomes during mitosis and meiosis. This organization is essential for the proper alignment and separation of chromosomes, ensuring accurate distribution of genetic material to daughter cells. Centrioles do not participate in forming the nuclear envelope, replicating DNA, or protein synthesis. Therefore, the correct answer is C, as centrioles are primarily involved in microtubule organization to facilitate cell division.

2. What is the function of ribosomes?

A. Packaging and transporting proteins
B. Storing genetic material
C. Controlling cell division
D. Synthesizing proteins

Correct answer: D

Rationale: The correct answer is D: 'Synthesizing proteins.' Ribosomes are the cellular organelles responsible for protein synthesis. They read the mRNA and assemble amino acids into proteins according to the genetic information encoded in the mRNA. This process is crucial for building and maintaining cellular structures, enzymes, and various other proteins essential for the functioning of the cell. Options A, B, and C do not accurately describe the primary function of ribosomes, making them incorrect choices for this question.

3. What is the formula to calculate acceleration?

A. Acceleration= Mass Force â€‹
B. Acceleration= Force Mass â€‹
C. Acceleration= Time Distance â€‹
D. Acceleration= Time Change in Velocity â€‹

Correct answer: A

Rationale: Acceleration is calculated as the change in velocity divided by the time taken.

4. The rigid structure that provides shape and support to plant cells is called the:

A. Cell wall
B. Plasma membrane
C. Nucleus
D. Cytoplasm

Correct answer: A

Rationale: The correct answer is A: Cell wall. The cell wall is a rigid structure found in plant cells, providing support and shape to the cell. It is composed mainly of cellulose, a tough and fibrous substance that helps plants maintain their structure. The plasma membrane, option B, is a semi-permeable membrane that surrounds the cell and regulates the passage of substances in and out of the cell. The nucleus, option C, is the control center of the cell that contains genetic material. Cytoplasm, option D, is the jelly-like substance that fills the cell and houses organelles. In this context, the function of providing shape and support points specifically to the cell wall, making it the correct choice.

5. The process by which a single-celled organism divides into two identical daughter cells is called

A. Conjugation
B. Binary fission
C. Endocytosis
D. Mitosis

Correct answer: B

Rationale: Rationale: A) Conjugation is a process in which genetic material is transferred between two bacterial cells through a conjugation tube. It does not involve the division of a single-celled organism into two identical daughter cells. B) Binary fission is the process by which a single-celled organism, such as a bacterium, divides into two identical daughter cells. This is a common method of reproduction in prokaryotic organisms. C) Endocytosis is a cellular process in which cells engulf external materials by wrapping them in a vesicle. It is not a method of cell division. D) Mitosis is a type of cell division that occurs in eukaryotic cells, leading to the production of two daughter cells with identical genetic material. However, the question specifically refers to a single-celled organism, which typically undergoes binary fission for reproduction.

6. 7 is divisible by which of the following numbers?

A. 2 only
B. 3 only
C. 1 and 7 only
D. 2, 3, and 7

Correct answer: D

Rationale: Rationale: 1. 7 is divisible by 1 because every number is divisible by 1. 2. 7 is divisible by 7 because any number is divisible by itself. 3. 7 is not divisible by 2 because 7 is an odd number and not divisible by 2. 4. 7 is not divisible by 3 because the sum of the digits of 7 (7) is not divisible by 3. Therefore, 7 is divisible by 1, 7, and itself (7), making the correct answer D) 2, 3, and 7.