1. Acne vulgaris, commonly known as acne, is primarily caused by

A. Dry skin (Dry skin can worsen acne but isn't the primary cause)
B. Clogged pores and excess oil production
C. Bacterial infection alone (Bacteria play a role but not the sole cause)
D. Vitamin deficiency

Correct answer: B

Rationale: The correct answer is B: 'Clogged pores and excess oil production.' Acne vulgaris, or acne, is primarily caused by a combination of factors including excess sebum (oil) production by the skin's sebaceous glands and the accumulation of dead skin cells, leading to clogged pores. This environment provides a breeding ground for acne-causing bacteria, contributing to inflammation and the formation of pimples. While factors like dry skin, bacterial infections, and even vitamin deficiencies can exacerbate acne, they are not the primary cause. Thus, B is the most accurate option for the primary cause of acne.

2. What property of a substance remains constant regardless of the amount of the substance present?

A. Mass
B. Weight
C. Density
D. Volume

Correct answer: c

Rationale: Density remains constant for a specific substance regardless of the quantity present. It's the mass per unit volume and remains the same for a substance.

3. What is the term for an organism with two different alleles for a gene?

A. Homozygous
B. Heterozygous
C. Dominant
D. Recessive

Correct answer: B

Rationale: An organism with two different alleles for a gene has a mixed genotype and may exhibit either the dominant or recessive trait depending on the specific gene and its alleles.

4. Which property of a wave determines its loudness in sound waves?

A. Amplitude
B. Wavelength
C. Frequency
D. Speed

Correct answer: a

Rationale: Amplitude in sound waves relates to the loudness or intensity of the sound.

5. What is the scientific name for the building blocks of proteins?

A. Residues
B. Monomers
C. Macromolecules
D. Peptides

Correct answer: B

Rationale: Rationale: - Proteins are made up of long chains of amino acids. - Amino acids are the building blocks of proteins and are considered monomers. - Monomers are the individual units that can be linked together to form larger molecules called polymers. - In the context of proteins, amino acids are the monomers that are linked together through peptide bonds to form polypeptide chains, which then fold into functional proteins. - Residues refer to the specific amino acids within a protein after certain modifications or cleavages have occurred, so it is not the correct term for the building blocks of proteins. - Macromolecules are large molecules made up of smaller subunits, such as proteins, nucleic acids, and carbohydrates, but they are not the specific building blocks of proteins. - Peptides are short chains of amino acids linked by peptide bonds, but they are not the fundamental building blocks of proteins.

6. A rocket blasts off from Earth. What is the main force propelling the rocket upwards?

A. Gravitational force
B. Air resistance
C. Thrust from the rocket engine
D. Normal force from the launchpad

Correct answer: C

Rationale: Thrust from the rocket engine. This force is produced by the action-reaction principle and pushes the rocket upwards against the exhaust gases.