Which of the following is NOT a function of the cilia lining the respiratory tract?
- A. Trapping inhaled dust and debris
- B. Moistening inhaled air
- C. Producing mucus
- D. Propelling mucus upwards towards the throat
Correct Answer: B
Rationale: The correct answer is B: Moistening inhaled air. The cilia lining the respiratory tract primarily function to trap inhaled dust and debris, produce mucus, and propel the mucus upwards towards the throat for removal. Moistening inhaled air is primarily done by the mucous membranes in the nasal passages, which contain blood vessels that help warm and humidify the air as it passes through the nasal cavity. Therefore, the function of moistening inhaled air is not directly associated with the cilia in the respiratory tract, making it the correct choice in this scenario. Choices A, C, and D are incorrect as they are all functions carried out by the cilia in the respiratory tract.
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What is the final stage of both mitosis and meiosis?
- A. Interphase
- B. Telophase
- C. Cytokinesis
- D. G1 phase
Correct Answer: B
Rationale: - Interphase (option A) is not the final stage of mitosis or meiosis; it is the phase before cell division where the cell prepares for division by growing and replicating its DNA.
- Telophase (option B) is the final stage of both mitosis and meiosis. During telophase, the separated chromosomes reach opposite poles of the cell, the nuclear membrane reforms around each set of chromosomes, and the chromosomes begin to decondense.
- Cytokinesis (option C) is the process of dividing the cytoplasm to form two separate daughter cells. While it occurs after telophase, it is not considered the final stage of mitosis or meiosis.
- G1 phase (option D) is the first gap phase in the cell cycle, occurring before DNA replication. It is not the final stage of mitosis or meiosis.
What is the term for the distance between the center of a lens or curved mirror and its focal point?
- A. Aperture
- B. Focal length
- C. Refractive index
- D. Lens thickness
Correct Answer: B
Rationale: The correct answer is B: Focal length. Focal length is the distance between the center of a lens or curved mirror and its focal point. It determines how strongly the lens converges or diverges light, affecting the image formation. Aperture, choice A, refers to the opening through which light enters the lens, controlling the amount of light passing through. Refractive index, choice C, measures how much light bends when passing through a medium, affecting the speed of light. Lens thickness, choice D, is the physical dimension of the lens, influencing optical properties and compatibility with frames.
What is the process of combining two or more substances to form a heterogeneous mixture called?
- A. Dissolving
- B. Diluting
- C. Mixing
- D. Reacting
Correct Answer: C
Rationale: The correct answer is 'Mixing.' When substances are combined, a heterogeneous mixture is formed where the components are physically distinguishable. 'Dissolving' (Choice A) is the process of a solute becoming uniformly dispersed in a solvent to form a solution, not a heterogeneous mixture. 'Diluting' (Choice B) refers to reducing the concentration of a solute in a solution. 'Reacting' (Choice D) involves a chemical change where substances interact to form new products, rather than just physically mixing to form a heterogeneous mixture.
Why is the electrical conductivity of a strong acid solution higher than that of a weak acid solution?
- A. Strong acids are more concentrated.
- B. Strong acids release more hydrogen ions.
- C. Weak acids are better at dissolving salts.
- D. Strong acids have a lower pH.
Correct Answer: B
Rationale: The correct answer is B because strong acids release more hydrogen ions compared to weak acids. This higher concentration of ions in the solution leads to a higher electrical conductivity. Strong acids ionize completely in solution, producing a higher concentration of ions that can conduct electricity, whereas weak acids only partially ionize, resulting in a lower concentration of ions and lower electrical conductivity. Choice A is incorrect because the concentration of the acid does not directly determine its electrical conductivity. Choice C is incorrect as the ability to dissolve salts is not directly related to electrical conductivity. Choice D is incorrect because the pH of the solution, although related to acidity, does not directly determine the electrical conductivity.
What type of inheritance pattern results in a 3:1 ratio of dominant to recessive phenotypes in the F2 generation?
- A. Incomplete dominance
- B. Codominance
- C. Sex-linked inheritance
- D. Autosomal dominant inheritance
Correct Answer: D
Rationale: Autosomal dominant inheritance results in a 3:1 ratio of dominant to recessive phenotypes in the F2 generation. This inheritance pattern occurs when a single copy of the dominant allele is enough to express the dominant phenotype.
A) Incomplete dominance: In incomplete dominance, the heterozygous phenotype is a blend of the two homozygous phenotypes, and it does not lead to a 3:1 ratio of dominant to recessive phenotypes in the F2 generation.
B) Codominance: In codominance, both alleles are fully expressed in the heterozygous phenotype, but this pattern also does not result in a 3:1 ratio of dominant to recessive phenotypes in the F2 generation.
C) Sex-linked inheritance: Sex-linked inheritance involves genes located on the sex chromosomes and does not typically lead to a 3:1 ratio of dominant to recessive phenotypes in the F2 generation.