1. You design an experiment to test the effectiveness of a new fertilizer. Which of the following factors would be considered a dependent variable?

A. The type of fertilizer used
B. The size and age of the plants
C. The amount of plant growth observed
D. The cost of the fertilizer per unit

Correct answer: C

Rationale: The dependent variable is the factor that is being measured or observed in an experiment. In this case, the amount of plant growth observed is the variable that is being influenced by the independent variable, which is the type of fertilizer used. The size and age of the plants (option B) could potentially be controlled variables, while the type of fertilizer used (option A) is the independent variable being tested. The cost of the fertilizer per unit (option D) is not directly related to the plant growth being measured in this experiment.

2. What is the structure that attaches to each chromosome during mitosis?

A. Centromere
B. Telomere
C. Spindle apparatus
D. Nucleolus

Correct answer: A

Rationale: Rationale: The centromere is the structure that attaches to each chromosome during mitosis. It is a region of the chromosome where the two sister chromatids are held together and where the spindle fibers attach during cell division. The centromere plays a crucial role in ensuring that each daughter cell receives the correct number of chromosomes during cell division. Telomeres are structures found at the ends of chromosomes that protect them from deterioration and fusion with neighboring chromosomes. The spindle apparatus is a structure made of microtubules that helps separate chromosomes during cell division. The nucleolus is a region within the nucleus where ribosomal RNA synthesis occurs and is not directly involved in chromosome attachment during mitosis.

3. A decorative box has a rectangular base (20cm by 15cm) and a hemispherical top with the same diameter as the base. What is the total surface area of the box (excluding the base)?

A. 825 sq cm
B. 1075 sq cm
C. 1325 sq cm
D. 1575 sq cm

Correct answer: C

Rationale: Calculate the surface area of the lateral sides and the hemisphere, then add them up.

4. What is the meaning of the phrase "to be on the same page"?

A. To be physically close
B. To agree or understand each other
C. To be sharing the same goal
D. To be facing the same direction

Correct answer: B

Rationale: The phrase means to be in agreement or share the same understanding.

5. Which vitamin is known to play a vital role in immune function?

A. Vitamin A
B. Vitamin B12
C. Vitamin D
D. Vitamin E

Correct answer: D

Rationale: The correct answer is Vitamin D. Vitamin D is known to play a vital role in immune function as it helps regulate the immune system's response to infections and reduces inflammation. It is involved in the production of antimicrobial peptides that help fight off pathogens. Vitamin A is important for vision and skin health, Vitamin B12 is essential for red blood cell formation and neurological function, and Vitamin E is an antioxidant that protects cells from damage. However, Vitamin D specifically stands out for its crucial role in supporting the immune system, making it the correct answer in this context.

6. 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.