1. 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.

2. What is the main function of the urinary system?

A. Transporting oxygen
B. Fighting off infections
C. Maintaining acid-base balance
D. All of the above

Correct answer: D

Rationale: The correct answer is D: 'All of the above.' The main function of the urinary system is not just limited to one specific task but encompasses multiple important functions. It is responsible for maintaining acid-base balance by regulating the pH of the blood through the excretion of acids and bases. Additionally, the urinary system plays a crucial role in filtering waste products from the blood and expelling them from the body, which helps in fighting off infections. Moreover, the urinary system is not involved in transporting oxygen, as this function is primarily carried out by the respiratory system. Therefore, 'All of the above' is the correct choice as it includes the comprehensive functions of the urinary system.

3. What is the primary function of DNA polymerase?

A. Packaging DNA
B. Replicating DNA
C. Transcribing DNA
D. Translating mRNA

Correct answer: B

Rationale: Rationale: DNA polymerase is an enzyme responsible for synthesizing new DNA strands during DNA replication. It adds nucleotides to the growing DNA strand based on the template provided by the existing DNA strand. This process ensures that genetic information is accurately copied and passed on to daughter cells during cell division. Packaging DNA (option A) refers to the coiling and organization of DNA into chromatin, a process involving histones and other proteins. Transcribing DNA (option C) involves the synthesis of RNA from a DNA template, a process carried out by RNA polymerase. Translating mRNA (option D) refers to the process of protein synthesis where the information encoded in mRNA is used to assemble amino acids into a polypeptide chain.

4. What is the role of DNA in heredity?

A. Provides energy for the cell
B. Determines the structure and function of proteins
C. Stores and transmits genetic information
D. Controls cell division

Correct answer: C

Rationale: Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

5. What is the role of RNA in the regulation of gene expression?

A. Provides energy for the process
B. Controls the timing and location of protein synthesis
C. Translates the genetic code into amino acids
D. Stores genetic information

Correct answer: B

Rationale: Rationale: A) RNA does not provide energy for the process of gene expression. Energy is typically provided by molecules like ATP. B) RNA plays a crucial role in controlling the timing and location of protein synthesis through processes like transcriptional regulation, RNA splicing, and post-transcriptional modifications. It helps determine when and where specific proteins are produced in the cell. C) While mRNA translates the genetic code into amino acids during the process of translation, this is not the primary role of RNA in the regulation of gene expression. D) RNA does not store genetic information in the same way that DNA does. DNA is the molecule responsible for storing genetic information in the form of genes. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in regulating gene expression.