1. What is the difference between a ventral and dorsal root of a spinal nerve?

A. Ventral carries motor, dorsal carries sensory information.
B. Ventral carries sensory, dorsal carries motor information.
C. Ventral is larger, dorsal is smaller.
D. Ventral is located anteriorly, dorsal is posteriorly.

Correct answer: A

Rationale: The correct answer is A: 'Ventral carries motor, dorsal carries sensory information.' Ventral roots of spinal nerves contain motor fibers that carry signals from the central nervous system to muscles and glands, controlling movement and function. Dorsal roots, on the other hand, contain sensory fibers that transmit information such as touch, pain, and temperature from the peripheral nervous system to the central nervous system for processing. Understanding this distinction is crucial for comprehending how information is transmitted and processed in the nervous system.

2. Which verb tense best fits the blank: "By next month, she _____ the project for a year."

A. will have been working on
B. will work on
C. has been working on
D. had worked on

Correct answer: C

Rationale: The sentence emphasizes the completed duration of the project by next month, requiring the present perfect continuous tense.

3. What is the building block of DNA?

A. Amino acid
B. Nucleotide
C. Nucleotide
D. Fatty acid

Correct answer: B

Rationale: Rationale: - Amino acids are the building blocks of proteins, not DNA. - Nucleotide is the correct building block of DNA. A nucleotide consists of a sugar (deoxyribose in DNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, or guanine). - The option "C) Nucleotide" is a duplicate of the correct answer "B) Nucleotide." - Fatty acids are not the building blocks of DNA; they are a type of lipid molecule.

4. Vaccines work by:

A. Directly killing pathogens
B. Introducing weakened or inactive versions of pathogens to trigger immune response
C. Stimulating production of specific antibodies immediately
D. None of the above

Correct answer: B

Rationale: The correct answer is B: Introducing weakened or inactive versions of pathogens to trigger an immune response. Vaccines work by exposing the immune system to a harmless version of a pathogen, which allows the body to recognize and develop a defense against the pathogen without causing illness. This process stimulates the immune system to produce memory cells that can quickly recognize and attack the pathogen if encountered in the future. Vaccines do not directly kill pathogens (option A) or immediately stimulate the production of specific antibodies (option C). Therefore, option B is the most accurate description of how vaccines work.

5. Which of the following structures plays a crucial role in controlling the cell cycle and preventing uncontrolled cell growth?

A. The centrioles
B. The nucleolus
C. The Golgi apparatus
D. The endoplasmic reticulum

Correct answer: A

Rationale: Rationale: - Centrioles are cylindrical structures found in animal cells that play a crucial role in organizing the spindle fibers during cell division (mitosis). They are involved in the separation of chromosomes during cell division, ensuring that each daughter cell receives the correct number of chromosomes. - Centrioles are also involved in the formation of cilia and flagella, which are important for cell motility and sensory functions. - The other structures listed in the options (nucleolus, Golgi apparatus, and endoplasmic reticulum) do not directly play a role in controlling the cell cycle and preventing uncontrolled cell growth.

6. What is the difference between a real image and a virtual image formed by a lens?

A. Real images can be projected onto a screen, while virtual images cannot.
B. Real images are always upright, while virtual images can be inverted.
C. Real images are formed by converging lenses, while virtual images are formed by diverging lenses.
D. All of the above are true.

Correct answer: A

Rationale: Real images are formed by the actual convergence of light rays and can be projected onto a screen, while virtual images are formed by the apparent divergence of light rays and cannot be projected.