Nokea
What is the basic structure of an atom?
- A. Protons, neutrons, electrons
- B. Protons, electrons, ions
- C. Neutrons, electrons, ions
- D. Protons, ions, molecules
Correct Answer: A
Rationale: The basic structure of an atom consists of protons and neutrons located in the nucleus, with electrons orbiting around the nucleus in specific energy levels or shells. Protons carry a positive charge, neutrons carry no charge, and electrons carry a negative charge. This arrangement maintains the overall neutrality of the atom, with the number of protons equaling the number of electrons. Therefore, the correct answer is 'Protons, neutrons, electrons.' Choices B, C, and D are incorrect as they do not accurately represent the fundamental components of an atom. Choice B includes 'ions,' which are charged particles, not fundamental components of an atom. Choice C includes 'ions' and lacks protons. Choice D includes 'ions' and 'molecules,' which are not part of the basic structure of an atom.
You may also like to solve these questions
Which of the following is directly transcribed from DNA and represents the first step in protein synthesis?
- A. siRNA
- B. rRNA
- C. mRNA
- D. tRNA
Correct Answer: C
Rationale: mRNA (messenger RNA) is directly transcribed from DNA in the nucleus during the process of transcription. It serves as a template for protein synthesis during translation in the cytoplasm. mRNA carries genetic information from the DNA to the ribosomes, where it determines the sequence of amino acids in a protein. Thus, mRNA represents the first step in protein synthesis as it carries the code from the DNA to be translated into a protein. Choice A, siRNA (small interfering RNA), is involved in post-transcriptional gene silencing and does not play a role in protein synthesis. Choice B, rRNA (ribosomal RNA), is a component of the ribosome and plays a structural and functional role in protein synthesis but is not directly transcribed from DNA. Choice D, tRNA (transfer RNA), is responsible for bringing amino acids to the ribosome during protein synthesis but is not directly transcribed from DNA.
Which statement is true about the pH of a solution?
- A. A solution cannot have a pH less than 0.
- B. A solution always has a pH of 7.
- C. A solution's pH is not influenced by its chemical composition.
- D. A solution with a pH of 14 is considered acidic.
Correct Answer: A
Rationale: The pH scale ranges from 0 to 14, with 0 being the most acidic, 7 neutral, and 14 the most basic. A solution with a pH less than 0 would be outside the defined pH range, as 0 is the lower limit. Therefore, a solution cannot have a pH less than 0. Choice B is incorrect because a pH of 7 is considered neutral, not always the pH of a solution. Choice C is incorrect because a solution's pH is influenced by its chemical composition. Choice D is incorrect as a solution with a pH of 14 is considered highly basic, not acidic.
What hormones are produced in the ovaries, and what are their functions?
- A. Insulin: regulates blood sugar levels
- B. Progesterone: stimulates uterine lining growth
- C. Adrenaline: increases heart rate
- D. Cortisol: regulates stress response
Correct Answer: B
Rationale: The correct answer is B. Progesterone, produced in the ovaries, stimulates uterine lining growth and plays a crucial role in regulating the menstrual cycle. Insulin is produced in the pancreas to regulate blood sugar levels, not in the ovaries. Adrenaline is produced by the adrenal glands and increases heart rate in response to stress or danger, not in the ovaries. Cortisol, also produced by the adrenal glands, helps regulate the body's response to stress, not in the ovaries.
What is the approximate composition of blood?
- A. 45% plasma, 55% formed elements
- B. 55% plasma, 45% formed elements
- C. 55% water, 45% blood cells
- D. 45% water, 55% plasma
Correct Answer: B
Rationale: Blood is composed of approximately 55% plasma (mostly water with proteins, electrolytes, and nutrients) and 45% formed elements (red blood cells, white blood cells, and platelets). Choice B is the correct answer. Choice A is incorrect as it reverses the percentages. Choice C is incorrect because it incorrectly states that blood cells make up 45% of blood, while they are part of the formed elements along with platelets. Choice D is incorrect as it suggests that water makes up 45% of blood, which is not accurate.
Identify the correct sequence of the 3 primary body planes as numbered 1, 2, and 3 in the above image.
- A. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is transverse.
- B. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is medial.
- C. Plane 1 is coronal, plane 2 is sagittal, and plane 3 is medial.
- D. Plane 1 is sagittal, plane 2 is coronal, and plane 3 is transverse.
Correct Answer: A
Rationale: In the standard anatomical position, plane 1 (coronal/frontal plane) divides the body into anterior and posterior portions, plane 2 (sagittal plane) divides the body into left and right portions, and plane 3 (transverse/horizontal plane) divides the body into superior and inferior portions. Therefore, the correct sequence is Plane 1 as coronal, Plane 2 as sagittal, and Plane 3 as transverse, which corresponds to Choice A. Choice B is incorrect as it misidentifies the planes. Plane 2 cannot be coronal as it specifically divides the body into left and right portions. Choice C is incorrect as it misidentifies Plane 2 as sagittal when it should be coronal. Choice D is incorrect as it incorrectly designates Plane 2 as coronal when it should be sagittal, leading to an inaccurate sequence of the primary body planes.