Nokea
Which of the following statements best defines an organelle?
- A. Layer of polysaccharides outside the plasma membrane of cells.
- B. Abnormal infectious proteins.
- C. Specialized structures within a cell.
- D. Collection of tissues used to serve a specific function.
Correct Answer: C
Rationale: The correct answer is C: 'Specialized structures within a cell.' An organelle is a specialized subunit within a cell that has a specific function. Organelles are membrane-bound structures found within the cytoplasm of eukaryotic cells, each performing distinct roles that contribute to the overall functioning of the cell. Choices A, B, and D are incorrect. Option A describes the glycocalyx, which is a layer of polysaccharides outside the plasma membrane of cells. Option B refers to prions, abnormal infectious proteins. Option D defines an organ, a collection of tissues used to serve a specific function, rather than an organelle within a cell.
You may also like to solve these questions
What is the control, if any, in this experiment?
- A. There is no control in this experiment
- B. The control is the water
- C. The control is the diet soda
- D. The control is the amount of sunlight provided to the plants
Correct Answer: B
Rationale: The correct answer is B: 'The control is the water.' In a scientific experiment, the control group is used as a baseline comparison to evaluate the effects of the variables being tested. Here, the water serves as the control group against which the effects of other substances like diet soda or different amounts of sunlight can be compared. Choice A is incorrect as every experiment should have a control group for comparison. Choice C and D are incorrect as they are not the standard control in this scenario.
What is the primary function of antibodies?
- A. Production of white blood cells
- B. Initiation of gluconeogenesis
- C. Promotion of intracellular storage of lipids
- D. Facilitate the breakdown of antigens
Correct Answer: D
Rationale: The correct answer is D: Facilitate the breakdown of antigens. Antibodies are protein molecules produced by the immune system in response to the presence of foreign substances, known as antigens, in the body. Antibodies bind to specific antigens and mark them for destruction by other immune cells, thereby helping the body to defend against infections and other threats. Choices A, B, and C are incorrect because antibodies do not have a direct role in the production of white blood cells, initiation of gluconeogenesis, or promotion of intracellular storage of lipids. The primary function of antibodies is to target and facilitate the destruction of antigens in the body.
Why is it essential to formulate a hypothesis before conducting an experiment?
- A. It will increase the investigator's reputation and prestige if their hypothesis is proven correct.
- B. The hypothesis helps guide the investigation by suggesting what the investigator should be looking for.
- C. Formulating a hypothesis shows potential sources of funding that the investigator has given some thought to the experiment.
- D. The hypothesis directs which results to keep and publish; results that do not match the hypothesis should be discarded.
Correct Answer: B
Rationale: Formulating a hypothesis before conducting an experiment is crucial because it helps guide the investigation by suggesting what the investigator should be looking for. A hypothesis serves as a prediction or an educated guess about what might happen in the experiment, providing a clear direction for the research process. It allows the investigator to focus on specific variables and outcomes, making the experiment more organized and effective. Choice A is incorrect because the primary purpose of a hypothesis is not to boost an investigator's reputation but to guide the research. Choice C is incorrect as formulating a hypothesis is not primarily about impressing funders but about setting a clear direction for the study. Choice D is incorrect because the hypothesis is not meant to dictate which results to keep based on preconceived notions but to guide the investigation and allow for unbiased interpretation of results.
What is the primary function of Bartholin's glands?
- A. Secretes hormones that help the body respond to stress
- B. Provide lubrication for the vagina
- C. Helps control growth and development of the body
- D. Stimulate the development of T cells
Correct Answer: B
Rationale: Bartholin's glands are two small glands located on each side of the vaginal opening. Their primary function is to secrete fluids that help lubricate the vagina during sexual arousal. This lubrication helps to reduce friction and discomfort during sexual activity, making intercourse more comfortable and pleasurable. Choices A, C, and D are incorrect because Bartholin's glands do not secrete hormones to respond to stress, control growth and development, or stimulate the development of T cells. Their main role is specifically related to vaginal lubrication.
If a scientist finds that the results of her experiment seem to contradict her hypothesis, what is the best course of action?
- A. Publish the results anyway, acknowledging that her hypothesis seems to have been incorrect.
- B. Keep trying the experiment until the results match her hypothesis.
- C. Publish the results, retroactively changing the hypothesis.
- D. None of the above; this cannot occur. The experimental results cannot contradict the hypothesis, by definition.
Correct Answer: A
Rationale: The best course of action is to publish the results anyway, acknowledging that her hypothesis seems to have been incorrect. Science relies on accurate reporting and transparency, even if the results do not align with the original hypothesis. This allows for further discussion, analysis, and potentially new hypotheses to be developed based on the findings. It is essential in scientific research to report both positive and negative results to contribute to the body of knowledge and advance understanding in the field. Choice B is incorrect because persisting with the same experiment to force results to align with the hypothesis goes against scientific integrity and may lead to biased conclusions. Choice C is incorrect as changing the hypothesis after obtaining results is not scientifically sound and undermines the credibility of the research. Choice D is incorrect because science embraces the possibility of experimental results contradicting hypotheses, as this provides valuable insights for refining theories and expanding scientific knowledge.