1. The fluid-filled sacs that cushion the brain within the skull are called:

A. Meninges
B. Cerebrospinal fluid
C. Dura mater
D. Arachnoid mater

Correct answer: B

Rationale: The correct answer is B: Cerebrospinal fluid. Cerebrospinal fluid is a clear, colorless fluid that surrounds the brain and spinal cord, acting as a cushion to protect the central nervous system from injury. Meninges (Option A) are the protective membranes that cover the brain and spinal cord, while the dura mater (Option C) and arachnoid mater (Option D) are specific layers of the meninges. However, cerebrospinal fluid is the fluid-filled sac that directly cushions the brain within the skull, making it the most appropriate answer for this question.

2. What is the importance of RNA splicing?

A. Removes introns from the mRNA molecule
B. Adds the poly-A tail to the mRNA molecule
C. Activates the mRNA molecule for translation
D. Modifies the structure of the protein

Correct answer: A

Rationale: Rationale: A) RNA splicing is a crucial process in gene expression where non-coding regions called introns are removed from the pre-mRNA molecule, and the remaining coding regions called exons are joined together to form the mature mRNA molecule. This process ensures that only the protein-coding sequences are retained in the mRNA for translation, allowing for the production of functional proteins. Therefore, option A is the correct answer as it accurately describes the importance of RNA splicing in generating mature mRNA molecules for protein synthesis. B) Adding the poly-A tail to the mRNA molecule is a post-transcriptional modification that occurs after RNA splicing and is not directly related to the process of removing introns. C) Activating the mRNA molecule for translation is typically achieved through the addition of a 5' cap and the poly-A tail, rather than through RNA splicing. D) Modifying the structure of the protein is not directly

3. The process of a gas changing directly into a solid is called:

A. Condensation
B. Deposition
C. Sublimation
D. Evaporation

Correct answer: B

Rationale: This process, also known as sublimation, involves gas particles losing energy and transitioning directly into the solid state.

4. What is the main purpose of biological classification?

A. To create a rigid and unchanging system for labeling organisms
B. To understand the diversity and interconnectedness of life
C. To simplify nature into neat and tidy categories
D. To assign organisms to specific ecological niches

Correct answer: B

Rationale: Rationale: Biological classification, also known as taxonomy, is the science of categorizing and organizing living organisms based on shared characteristics. The main purpose of biological classification is not to create a rigid and unchanging system (option A) or to simplify nature into neat and tidy categories (option C). Instead, it aims to help us understand the diversity of life on Earth and how different organisms are related to each other. By classifying organisms into groups based on their evolutionary relationships, we can gain insights into the interconnectedness of life and better appreciate the complexity and beauty of the natural world. Assigning organisms to specific ecological niches (option D) is more related to ecological studies rather than biological classification.

5. Which type of energy is possessed by an object in motion?

A. Potential energy
B. Kinetic energy
C. Thermal energy
D. Chemical energy

Correct answer: b

Rationale: Kinetic energy is the energy possessed by an object in motion.

6. A ball is thrown horizontally off a cliff with a speed of 10 m/s. What is the horizontal distance the ball travels before hitting the ground?

A. 10 m
B. 20m
C. 30m
D. Cannot be determined without knowing the height of the cliff

Correct answer: C

Rationale: When a ball is thrown horizontally, its horizontal velocity remains constant throughout its motion. The time taken to hit the ground is determined by the vertical motion, which is independent of the horizontal velocity. Therefore, the horizontal distance traveled by the ball is determined by the horizontal velocity and the time taken to hit the ground. In this case, the horizontal distance is calculated as distance = velocity × time = 10 m/s × time. Since the horizontal velocity is 10 m/s and the time taken to hit the ground is determined by the vertical motion, the horizontal distance traveled by the ball is 10 m/s × time. Without knowing the height of the cliff, we can still determine the horizontal distance traveled by the ball, which is 10 m/s × time.