1. What skin condition is characterized by red, itchy, and inflamed patches?

A. Eczema
B. Psoriasis
C. Melanoma
D. Keloid

Correct answer: A

Rationale: The correct answer is A: Eczema. Eczema is a common skin condition that is characterized by red, itchy, and inflamed patches on the skin. It is often triggered by environmental factors or allergies and can vary in severity. Psoriasis (option B) is also a skin condition that causes red, scaly patches on the skin, but it is typically thicker and more silver or white in color compared to eczema. Melanoma (option C) is a type of skin cancer that usually presents as a new mole or a changing mole on the skin, rather than red, itchy patches. Keloid (option D) is a raised scar that can result from an overgrowth of scar tissue. Therefore, the most appropriate answer to this question is A: Eczema, based on the description of red, itchy, and inflamed patches.

2. What is the characteristic property of acids?

A. Bitter taste
B. Sour taste
C. Slippery feel
D. Sweet taste

Correct answer: b

Rationale: Acids typically have a sour taste. The other choices do not accurately describe the characteristic properties of acids.

3. What is the main target organ for insulin, the hormone produced by the pancreas?

A. Liver
B. Kidneys
C. Muscles
D. Brain

Correct answer: C

Rationale: The correct answer is C: Muscles. Insulin is a hormone produced by the pancreas that plays a crucial role in regulating blood sugar levels. Its main target organs are the liver, muscles, and adipose tissue. Insulin acts on muscle cells to promote glucose uptake and storage as glycogen, helping to lower blood sugar levels. While the liver and adipose tissue are also important targets for insulin, muscles are particularly significant for glucose utilization and storage. Therefore, muscles are considered the main target organ for insulin in the body.

4. How many moles of water are produced when 0.5 moles of methane (CH4) react with excess oxygen?

A. 0.5 moles
B. 1 mole
C. 2 moles
D. 3 moles

Correct answer: c

Rationale: The balanced equation is CH4 + 2O2 â†’ CO2 + 2H2O, indicating a 1:2 ratio between CH4 and H2O.

5. Which property of a wave determines its pitch in sound waves?

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

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency refers to the number of cycles of a wave that occur in a unit of time, usually measured in hertz (Hz). Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the height of a wave and is related to the loudness of the sound. Wavelength is the distance between two consecutive points in a wave that are in phase, and speed is the rate at which a wave travels through a medium.

6. What is the main function of peroxisomes in the cell?

A. To break down hydrogen peroxide
B. To synthesize lipids and other cellular components
C. To package and transport proteins
D. To store genetic material

Correct answer: A

Rationale: Rationale: Peroxisomes are membrane-bound organelles found in eukaryotic cells that contain enzymes involved in various metabolic processes. One of the main functions of peroxisomes is to break down hydrogen peroxide, a toxic byproduct of metabolism, into water and oxygen through the action of the enzyme catalase. This process helps protect the cell from oxidative damage caused by hydrogen peroxide. While peroxisomes are involved in other metabolic functions such as lipid metabolism and the synthesis of bile acids, their primary role is the breakdown of hydrogen peroxide.