1. What is the term for the shedding of the outermost layer of the epidermis?

A. Desquamation
B. Exfoliation
C. Keratinization
D. Epidermolysis

Correct answer: A

Rationale: The correct term for the shedding of the outermost layer of the epidermis is desquamation. Desquamation is a natural process where old skin cells are shed off to make way for new cells. Exfoliation refers to the removal of dead skin cells through external means like scrubs. Keratinization is the process by which skin cells produce the protein keratin, while epidermolysis is a condition where the epidermis separates from the dermis. Therefore, in this context, desquamation is the most appropriate term for the shedding of the outermost layer of the epidermis.

2. Which macromolecule serves as the repository of genetic information in all living organisms?

A. Ribonucleic acid (RNA)
B. Deoxyribonucleic acid (DNA)
C. Protein
D. Carbohydrate

Correct answer: B

Rationale: Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

3. A guitar string vibrates at a fundamental frequency of 440 Hz. What is the frequency of the second harmonic (first overtone)?

A. 220 Hz
B. 440 Hz
C. 880 Hz
D. 1760 Hz

Correct answer: C

Rationale: Harmonics have frequencies that are multiples of the fundamental frequency. The second harmonic has a frequency twice the fundamental, so it's 440 Hz * 2 = 880 Hz.

4. Which of the following is a characteristic of alkenes?

A. They have a double bond between carbon atoms.
B. They are saturated hydrocarbons.
C. They contain only single bonds.
D. They are derivatives of ammonia.

Correct answer: A

Rationale: Alkenes have a double bond between carbon atoms, making them unsaturated hydrocarbons. The other choices do not accurately describe alkenes.

5. A scientist observes a new species of bird with uniquely shaped wings. They hypothesize that the wing shape allows for superior gliding ability. Which observation would most strongly support this hypothesis?

A. The bird is found in mountainous regions.
B. The bird has feathers with low friction.
C. The bird can fly long distances without flapping.
D. The bird's wing muscles are stronger than other birds.

Correct answer: C

Rationale: Direct observation of gliding ability directly tests the hypothesis about the wing shape's function. Other observations might be relevant but provide less direct evidence.

6. Which statement is TRUE about valence electrons?

A. They are located in the innermost electron shell.
B. They have the highest binding energy to the nucleus.
C. They are most likely to participate in chemical bonding.
D. They have no influence on the element's chemical properties.

Correct answer: C

Rationale: They are most likely to participate in chemical bonding - Valence electrons occupy the outermost shell and are readily involved in forming bonds with other atoms.