Nokea
Which of the following structures is a mass within the ovary that secretes hormones to maintain the uterine lining during pregnancy?
- A. Oviduct
- B. Umbilical cord
- C. Oocyte
- D. Corpus luteum
Correct Answer: D
Rationale: The correct answer is the corpus luteum. The corpus luteum is a temporary endocrine structure in the ovary that forms after ovulation. It secretes hormones, primarily progesterone, which are essential to maintain the uterine lining during pregnancy. The other options, such as the oviduct, umbilical cord, and oocyte, do not have the function of secreting hormones to support the uterine lining in pregnancy.
You may also like to solve these questions
What type of tissue primarily makes up the pharynx?
- A. Bone
- B. Muscle
- C. Nervous
- D. Cartilage
Correct Answer: B
Rationale: The pharynx is primarily composed of muscle tissue. Muscle tissue in the pharynx plays a crucial role in functions such as swallowing and breathing. It allows the pharynx to contract and relax, facilitating the movement of food and air through this vital passage in the throat.
In light of the recent discovery that worm infection can relieve certain autoimmune disorders, how should the hypothesis be modified regarding parasitic infections?
- A. Worm infection reduces certain autoimmune disorders.
- B. Worm infestation is a cause of some autoimmune disorders.
- C. Worm infestation prevents immune malfunction.
- D. Worm infections exacerbate immune reactions.
Correct Answer: A
Rationale: The recent discovery that worm infection can relieve certain autoimmune disorders suggests a need to modify the hypothesis. Instead of viewing all parasitic infections as harmful, the new information indicates that worm infection can actually reduce certain autoimmune disorders. This challenges the previous belief and highlights a potential therapeutic benefit. Choices B, C, and D do not reflect the new understanding and should be eliminated. Therefore, option A, 'Worm infection reduces certain autoimmune disorders,' aligns with the updated hypothesis based on the recent discovery and is the correct answer.
Which component of an atom has relatively little mass that is considered negligible when calculating the atomic mass number?
- A. Neutron
- B. Proton
- C. Electron
- D. Quark
Correct Answer: C
Rationale: The correct answer is C: Electron. Electrons have significantly less mass compared to protons and neutrons, making their contribution to the atomic mass number negligible. When calculating the atomic mass, the mass of electrons is typically not factored in due to their minimal mass compared to the other components of the atom. While protons and neutrons contribute significantly to the atomic mass number, electrons, due to their much smaller mass, are considered to have a negligible impact on the overall calculation. Therefore, electrons can be disregarded when determining the atomic mass of an atom.
The triple point of a substance is the temperature and pressure at which of the substance exists as which of the following?
What is the triple point of a substance?
- A. Simultaneously in solid, liquid, and gas phases.
- B. As soil with gas and solid trapped in liquid.
- C. As a gel with solid and liquid trapped in gas.
- D. Simultaneously in solid, gel, and plasma phases.
Correct Answer: A
Rationale: The triple point of a substance refers to the specific temperature and pressure at which the substance can exist in equilibrium as solid, liquid, and gas phases simultaneously. This unique point represents the conditions under which all three phases coexist in equilibrium, allowing for phase transitions without a change in temperature or pressure. It is a crucial concept in thermodynamics and phase diagrams, illustrating the conditions where a substance can exhibit distinct phases simultaneously.
Which of the following statements is correct regarding the pH scale?
- A. A substance with a pH of 3 is more acidic than a substance with a pH of 4.
- B. A substance with a pH of 3 is two times more alkaline than a substance with a pH of 4.
- C. A substance with a pH of 3 is 10 times more alkaline than a substance with a pH of 4.
- D. A substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4.
Correct Answer: D
Rationale: The correct answer is D. The pH scale measures the acidity or basicity of a substance on a scale of 0 to 14. Each whole pH value below 7 is ten times more acidic than the next higher value. Therefore, a substance with a pH of 3 is 10 times more acidic than a substance with a pH of 4. The difference in pH values indicates the concentration of hydrogen ions in the substance, with lower pH values representing higher acidity and higher pH values representing higher basicity.