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What type of bond holds water molecules together?
- A. Covalent bond
- B. Hydrogen bond
- C. Ionic bond
- D. Peptide bond
Correct Answer: B
Rationale: The correct answer is B: Hydrogen bond. Hydrogen bonds are responsible for holding water molecules together. In a water molecule, the oxygen atom is slightly negative, and the hydrogen atoms are slightly positive, creating a partial positive and negative charge. This polarity allows hydrogen bonds to form between adjacent water molecules. Covalent bonds involve the sharing of electrons, ionic bonds involve transfer of electrons between ions, and peptide bonds are specific to linking amino acids in proteins, which are not relevant to water molecule interactions.
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What is the best tool to measure the volume of a solid?
- A. Triple beam balance
- B. Measuring wheel and mathematical formula
- C. Graduated cylinder
- D. Measuring wheel
Correct Answer: C
Rationale: A graduated cylinder is the most suitable tool to measure the volume of both liquids and solids. It works by measuring the displacement of water when the solid is submerged in the graduated cylinder. Choice A, the triple beam balance, is used to measure mass, not volume. Choice B, using a measuring wheel and mathematical formula, is typically used to measure distance or area, not volume. Choice D, a measuring wheel, is used to measure distance, making it inappropriate for measuring the volume of a solid.
A researcher wants to conduct qualitative research. Which method should they use?
- A. Collecting patient narratives
- B. Tracking the dosage of a drug and its blood levels in the patient
- C. Observing a patient's physical changes
- D. Writing journal notes about the research experience
Correct Answer: A
Rationale: Qualitative research focuses on gathering non-numerical, descriptive data to explore experiences, behaviors, or perspectives. Collecting patient narratives aligns with qualitative research as it involves capturing detailed accounts of individuals' experiences or viewpoints. Choices B, C, and D involve more quantitative approaches by focusing on measurable quantities, observations, or structured note-taking, which are not characteristic of qualitative research methods.
Which structure in the lungs is the site of gas exchange?
- A. Trachea
- B. Alveoli
- C. Bronchioles
- D. Diaphragm
Correct Answer: B
Rationale: The correct answer is B: Alveoli. Alveoli are tiny air sacs in the lungs where gas exchange occurs. Oxygen from inhaled air diffuses into the bloodstream, while carbon dioxide from the blood is released into the alveoli to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs, but it is not involved in gas exchange. Bronchioles (Choice C) are small air passages within the lungs that branch off from the bronchi, leading air to the alveoli but not directly involved in gas exchange. The diaphragm (Choice D) is a muscle below the lungs that helps in breathing by expanding and contracting the chest cavity, but it is not the site of gas exchange.
Which blood type is known as the universal donor?
- A. Type A
- B. Type B
- C. Type AB
- D. Type O
Correct Answer: D
Rationale: Type O blood is known as the universal donor because it lacks antigens on the surface of red blood cells. This characteristic makes it compatible with all blood types during transfusions. Type A, Type B, and Type AB blood types have specific antigens that can cause adverse reactions if transfused to an incompatible recipient.
Which part of the digestive system is responsible for absorbing water and forming feces?
- A. Stomach
- B. Small intestine
- C. Large intestine
- D. Esophagus
Correct Answer: C
Rationale: The correct answer is the large intestine. The large intestine is responsible for absorbing water and forming feces from undigested food. The stomach's main function is to break down food with acid and enzymes. The small intestine is where most of the nutrients are absorbed into the bloodstream. The esophagus is the tube that connects the mouth to the stomach and does not play a role in absorbing water or forming feces.