Which of the following is considered an extensive property?
- A. Weight
- B. Density
- C. Conductivity
- D. Malleability
Correct Answer: A
Rationale: Weight is correctly identified as an extensive property. Extensive properties are dependent on the amount of the substance present. Weight is directly proportional to the quantity of the substance, making it an extensive property. In contrast, density, conductivity, and malleability are intensive properties, which remain constant regardless of the amount of substance. Therefore, the correct answer is 'Weight' as it changes with the quantity of the substance, aligning with the definition of an extensive property.
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Which human body system is correctly matched with its function?
- A. Respiratory system; exchanges oxygen and carbon dioxide in the lungs.
- B. Circulatory system; transports oxygen to cells and removes carbon dioxide.
- C. Lymphatic system; produces antibodies that destroy virally affected or foreign cells.
- D. Endocrine system; regulates hormones controlling bodily functions and metabolism.
Correct Answer: B
Rationale: The circulatory system is responsible for the transportation of oxygen from the lungs to all the body's cells and tissues, as well as removing carbon dioxide from the cells and transporting it back to the lungs to be exhaled. This process is crucial for cellular respiration and the exchange of gases necessary for bodily functions. Choice B accurately matches the role of the circulatory system by describing its function of transporting oxygen to cells and removing carbon dioxide, which is essential for maintaining proper cellular activities. Choices A, C, and D are incorrect because they do not accurately match the body system with its function. The respiratory system primarily involves the exchange of gases in the lungs, not transportation to cells; the lymphatic system deals with immunity through the production of antibodies, not gas exchange; and the endocrine system's main function is hormone regulation, not the transport of gases.
Which of the following describes an experiment?
- A. The final math grades for a group of students passing through each year of elementary school are examined.
- B. The health trends of smokers in a small random sample are examined.
- C. Citizens in a local community are surveyed to determine concerns related to the next election.
- D. The effects of a new drug are tested on a group of participants.
Correct Answer: D
Rationale: Option D describes an experiment because it involves testing the effects of a new drug on a group of participants. In an experiment, researchers intentionally manipulate an independent variable (in this case, the new drug) to observe its effects on a dependent variable (the participants' health outcomes). This method allows for establishing cause-and-effect relationships between variables, which is a key characteristic of experimental research design. Choices A, B, and C do not represent experiments. Choice A involves observational analysis of math grades, choice B involves observational analysis of health trends, and choice C involves a survey, none of which involve manipulating variables to establish cause-and-effect relationships.
In a scientific investigation, what is the first step?
- A. Analysis of results
- B. Drawing conclusions
- C. Formation of hypothesis
- D. Performing the experiment
Correct Answer: C
Rationale: The correct answer is C: Formation of hypothesis. In a scientific investigation, forming a hypothesis is the initial step. A hypothesis is an educated guess or prediction based on existing knowledge and observations. It helps guide the experiment and provides a direction for the research process. Without a hypothesis, there is no specific aim or goal for the experiment. Choices A, B, and D are incorrect because they occur after the formation of a hypothesis. Analysis of results and drawing conclusions typically come after the experiment has been conducted, while performing the experiment is done to test the hypothesis formed at the beginning of the investigation.
What is correct about the hormones that stimulate male and female organs to produce male and female sex hormones?
- A. Female organs are stimulated by female hormones and male organs by male hormones.
- B. The same hormones that produce male or female sex characteristics stimulate the organs.
- C. The same hormones stimulate both male and female organs to produce sex hormones.
- D. The hypothalamus stimulates the pituitary gland's secretion of male and female hormones.
Correct Answer: C
Rationale: The correct answer is C. The same hormones stimulate both male and female organs to produce sex hormones. Hormones such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are produced by the pituitary gland and act on the ovaries in females and the testes in males to stimulate the production of sex hormones (estrogen and progesterone in females, testosterone in males). Therefore, the same hormones stimulate both male and female organs to produce sex hormones. Choices A, B, and D are incorrect because they do not accurately describe the relationship between hormones and the stimulation of male and female organs to produce sex hormones.
When a patient is lying flat on their back, which of the following positions are they in?
- A. Prone.
- B. Supine.
- C. Lateral.
- D. Medial.
Correct Answer: B
Rationale: When a patient is lying flat on their back, they are in the supine position. In the supine position, the person's face is facing upward, and their back is touching the surface they are lying on. This position is commonly used for medical examinations and procedures. Choice A, 'Prone,' refers to lying face down, not on the back. Choice C, 'Lateral,' indicates lying on the side. Choice D, 'Medial,' pertains to the middle or center, not a position in relation to lying on the back.
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