1. The outermost layer of the skin, providing protection against pathogens and the environment, is the:

A. Dermis
B. Epidermis
C. Hypodermis
D. Stratum corneum (part of the epidermis)

Correct answer: D

Rationale: The correct answer is D, 'Stratum corneum (part of the epidermis).' The stratum corneum is the outermost layer of the epidermis, consisting of dead skin cells that provide a protective barrier against pathogens and environmental factors. The dermis is located beneath the epidermis and contains connective tissue, nerves, and blood vessels. The hypodermis is the deepest layer of the skin, consisting of fat and connective tissue. Understanding the layers of the skin and their functions is essential for comprehending the skin's role in protecting the body.

2. In the reaction 4Al + 3O2 â†’ 2Al2O3, what is the mole ratio of aluminum to oxygen?

A. 4:3
B. 2:3
C. 3:2
D. 3:4

Correct answer: a

Rationale: The coefficients in the balanced equation represent the mole ratio, which is 4 moles of Al to 3 moles of O2.

3. Bone is a type of

A. Epithelial tissue
B. Connective tissue
C. Hard connective tissue
D. Muscle tissue

Correct answer: C

Rationale: The correct answer is C: "Hard connective tissue." Bone is classified as hard connective tissue because it is composed of cells embedded in a matrix of mineralized collagen fibers, providing support and protection to the body. Epithelial tissue (A) covers body surfaces and lines cavities, while connective tissue (B) includes bone, cartilage, and blood. Muscle tissue (D) is responsible for movement and is not the same as bone tissue.

4. Identify the compound-complex sentence in the following options:

A. The baker decorated the cake, and then he presented it proudly.
B. Although it was raining, the children played outside.
C. When the sun rises, the birds begin to sing.
D. He enjoyed reading the book because it was suspenseful.

Correct answer: D

Rationale: A compound-complex sentence contains at least two independent clauses and at least one dependent clause.

5. Which sentence uses the past perfect tense correctly?

A. By the time I arrived, the party had already begun.
B. I wish I had studied harder for the exam.
C. We will have finished the project by Monday.
D. She had been waiting for hours before he finally showed up.

Correct answer: A

Rationale: Option A expresses an action ("party began") completed before another past action ("I arrived").

6. Which of the following is the main function of the small intestine?

A. To store food and break it down into smaller pieces
B. To absorb nutrients into the bloodstream
C. To produce enzymes that help digest food
D. To eliminate waste products from the body

Correct answer: B

Rationale: Rationale: The small intestine is a crucial part of the digestive system where the majority of nutrient absorption takes place. It is lined with tiny finger-like projections called villi that increase the surface area for absorption. The small intestine absorbs nutrients such as carbohydrates, proteins, fats, vitamins, and minerals from the digested food into the bloodstream to be transported to cells throughout the body for energy, growth, and repair. Options A, C, and D do not accurately describe the main function of the small intestine.