Nokea
What is the initial step of the scientific method?
- A. construct a hypothesis
- B. make observations
- C. analyze data
- D. form a question
Correct Answer: B
Rationale: The first step of the scientific method is to make observations. This involves collecting data and information about a specific phenomenon or problem. Observations serve as the basis for developing a question to be explored further. Forming a hypothesis (Choice A) comes after making observations, as the hypothesis is an educated guess to explain the observations. Analyzing data (Choice C) occurs later in the scientific method after data has been collected and experiments conducted. Forming a question (Choice D) is a crucial step but typically follows observations in the scientific process.
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What is the primary function of the large intestine?
- A. absorbing digested material into the blood
- B. nutrient processing and metabolizing
- C. absorbing water and compacting material into solid waste
- D. bile production and storage
Correct Answer: C
Rationale: The large intestine's primary function is to absorb water from undigested food remnants and compact them into solid waste (feces). This process helps regulate hydration levels in the body and aids in waste elimination. Choices A, B, and D are incorrect. Absorbing digested material into the blood is mainly done in the small intestine, nutrient processing and metabolizing occur in various parts of the digestive system, and bile production and storage are functions of the liver and gallbladder, not the large intestine.
Which of the following is NOT a function of the liver?
- A. nutrient processing
- B. blood filtration and detoxification
- C. cholesterol and lipoprotein production
- D. insulin production and blood sugar regulation
Correct Answer: D
Rationale: The correct answer is D. The liver does not produce insulin; instead, insulin is produced by the pancreas. The liver plays a crucial role in regulating blood sugar levels by storing and releasing glucose but does not directly produce insulin. Choices A, B, and C are functions of the liver. Nutrient processing, blood filtration, detoxification, cholesterol, and lipoprotein production are essential roles performed by the liver to maintain overall metabolic balance and health.
What term describes a series of muscle contractions that transports food down the digestive tract in a wave-like fashion?
- A. digestion
- B. deglutition
- C. defecation
- D. peristalsis
Correct Answer: D
Rationale: Peristalsis is the correct term for the series of muscle contractions that move food down the digestive tract in a wave-like manner. This process helps propel food through the esophagus, stomach, and intestines, facilitating digestion and nutrient absorption. Digestion (Choice A) refers to the breakdown of food into smaller components, deglutition (Choice B) is the act of swallowing, and defecation (Choice C) is the elimination of waste from the body. Therefore, peristalsis is the most appropriate term to describe the described muscle contractions in the digestive system.
Which of the following is an example of adaptive immunity?
- A. Inflammation
- B. Fever
- C. Antibodies
- D. Phagocytosis
Correct Answer: C
Rationale: Antibodies are produced by the adaptive immune system in response to specific antigens. They play a crucial role in targeting and neutralizing pathogens, providing long-lasting immunity against future infections. In contrast, options A (inflammation), B (fever), and D (phagocytosis) are examples of innate immunity, the body's immediate, non-specific defense mechanisms. Inflammation is a response to tissue damage, fever is a systemic response to infection, and phagocytosis is a process where cells engulf and digest pathogens, all part of the innate immune response.
What type of reaction is represented by the following equation: 2C₆Hâ‚â‚„ + 19Oâ‚‚ → 12CO + 14Hâ‚‚O?
- A. Substitution reaction
- B. Acid-base reaction
- C. Enzyme reaction
- D. Combustion reaction
Correct Answer: D
Rationale: The given chemical equation represents a combustion reaction. Combustion reactions involve the burning of a hydrocarbon (C₆Hâ‚â‚„) in the presence of oxygen (Oâ‚‚) to produce carbon monoxide (CO) and water (Hâ‚‚O). Combustion reactions typically release heat and light energy. In this case, the reactants are a hydrocarbon and oxygen, resulting in the formation of carbon monoxide and water. Choices A, B, and C are incorrect because the reaction does not involve substitution, acid-base reactions, or enzyme catalysis. Combustion reactions are characterized by the rapid combination of a substance with oxygen, leading to the production of heat and light energy.