Which statement is true regarding the process of digestion?

Correct Answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.

Correct Answer: C

Rationale: The correct answer is C, 'Three.' The uterus is composed of three tissue layers: the endometrium, myometrium, and perimetrium. The endometrium is the innermost layer that thickens during the menstrual cycle and sheds during menstruation or supports a developing embryo during pregnancy. The myometrium is the middle layer, consisting of muscle tissue that contracts during labor. The perimetrium is the outer layer that covers the uterus. These three layers work together to support the functions of the uterus, such as menstruation, pregnancy, and labor. Choices A, B, and D are incorrect because the uterus is not made up of just one or two layers but rather three distinct tissue layers.

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.

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.

Correct Answer: B

Rationale: A neuron consists of three main parts: dendrites, axon, and cell body. Dendrites receive signals from other neurons or sensory receptors. The cell body (soma) contains the nucleus and organelles essential for neuron function. The axon transmits electrical impulses away from the cell body to other neurons, muscles, or glands. Choice A is incorrect because an effector is not a part of a neuron. Choice C is incorrect because a receptor is not a component of a neuron but rather interacts with neurons. Choice D is incorrect because the synapse is a junction between neurons for signal transmission, not a structural part of a neuron.

Correct Answer: A

Rationale: The correct answer is A: Glial cells. Glial cells are responsible for producing the myelin sheaths that surround and insulate nerve cells in the central and peripheral nervous systems. Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system are types of glial cells that form the myelin sheaths. Choice B, dendrites, are not involved in forming myelin sheaths; they are extensions of neurons that receive signals. Choice C, melanocytes, are cells responsible for producing melanin, not myelin. Choice D, squamous cells, are flat epithelial cells found in various tissues but are not involved in myelin sheath formation.

Correct Answer: B

Rationale: The correct answer is B - Stomach. The stomach is primarily involved in the digestive system, breaking down food through digestion. In contrast, the thyroid gland, intestines, and pancreas are part of the endocrine system or digestive system, involved in hormone production, nutrient absorption, and digestion. Therefore, the stomach stands out as the odd one in this group as it is the only organ specifically dedicated to digestion, while the others have dual roles or different primary functions.

Correct Answer: B

Rationale: The brain is a crucial organ that serves as the command center of the body, making it a key component of the nervous system. It processes sensory information, coordinates movements, and regulates various bodily functions. Therefore, the brain is correctly categorized as part of the nervous system. Choices A, C, and D are incorrect because the integumentary system pertains to the skin, the endocrine system involves hormone regulation, and the respiratory system is responsible for breathing. These systems do not encompass the brain's functions or structure.

Correct Answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.