Nokea
What is the building block of RNA?
- A. Amino acid
- B. Nucleotide
- C. Protein
- D. Fatty acid
Correct Answer: B
Rationale: Nucleotide: Nucleotides are the building blocks of RNA. A nucleotide consists of a nitrogenous base (adenine, guanine, cytosine, or uracil in RNA), a sugar (ribose in RNA), and a phosphate group. A) Amino acid: Amino acids are the building blocks of proteins, not RNA. C) Protein: Proteins are made up of amino acids, not nucleotides. D) Fatty acid: Fatty acids are components of lipids, not RNA.
You may also like to solve these questions
What pigment is responsible for the yellow color of bananas?
- A. Potassium
- B. Calcium
- C. Phosphorus
- D. Carotene
Correct Answer: D
Rationale: Carotene is the pigment responsible for the yellow color of bananas. It belongs to a group of plant pigments called carotenoids, which are responsible for giving fruits and vegetables their vibrant colors, including the yellow hue of bananas. Potassium, calcium, and phosphorus are essential minerals found in bananas but are not responsible for their yellow color.
Which property of a substance remains constant regardless of changes in its shape or size?
- A. Mass
- B. Weight
- C. Volume
- D. Density
Correct Answer: A
Rationale: The correct answer is 'Mass.' Mass is a measure of the amount of matter in an object and remains constant regardless of changes in its shape or size. Weight, volume, and density can all change depending on the conditions, but mass remains the same. Weight is the force exerted on an object due to gravity, which can change based on the gravitational pull. Volume is the amount of space an object occupies, which can change if the shape or size of the object changes. Density is the mass of a substance per unit volume, which can change if either the mass or volume changes. Therefore, in this scenario, mass is the property that remains constant regardless of changes in shape or size.
What is the term for the process of converting a liquid into a gas at a temperature below its boiling point?
- A. Vaporization
- B. Evaporation
- C. Condensation
- D. Sublimation
Correct Answer: B
Rationale: Evaporation is the correct term for the process of converting a liquid into a gas at a temperature below its boiling point. During evaporation, molecules of the liquid gain enough energy to escape into the gas phase, primarily occurring at the liquid's surface. Vaporization is a broader term that encompasses the conversion of a substance from a liquid or solid state to a gas, not specifically at temperatures below the boiling point. Condensation is the reverse process of evaporation, involving the conversion of a gas into a liquid. Sublimation, on the other hand, refers to the direct transition of a substance from the solid phase to the gas phase without passing through the liquid phase.
What phenomenon occurs when light passes through a medium without changing direction, such as when passing through a window?
- A. Diffraction
- B. Reflection
- C. Dispersion
- D. Transmission
Correct Answer: D
Rationale: The correct answer is 'Transmission.' Transmission refers to the phenomenon where light passes through a medium without changing direction, as observed when light passes through a window. Diffraction involves the bending of light waves around obstacles, reflection is the bouncing back of light waves from a surface, and dispersion is the separation of light into its different colors. In this case, the question specifically asks about the situation where light passes through a medium without changing direction, which aligns with the process of transmission.
Why is warming up before exercise important?
- A. To prevent dehydration
- B. To prevent muscle soreness
- C. To prevent increased heart rate
- D. To prevent low blood sugar
Correct Answer: B
Rationale: Warming up before exercise is crucial to prevent muscle soreness. It helps by increasing blood flow to the muscles, improving flexibility, and preparing the body for physical activity. Dehydration, increased heart rate, and low blood sugar are not directly prevented by warming up before exercise. Dehydration is prevented by proper hydration before and during exercise; increased heart rate is a normal physiological response to exercise; and low blood sugar is managed through proper nutrition and timing of meals before physical activity.