Nokea
Which element has the same number of protons and neutrons?
- A. Carbon (C)
- B. Oxygen (O)
- C. Lithium (Li)
- D. Helium (He)
Correct Answer: D
Rationale: The correct answer is Helium (He). Helium has an atomic number of 2, meaning it has 2 protons. It also has 2 neutrons, which gives it a total mass number of 4. Therefore, Helium is an example of an element with an equal number of protons and neutrons.
Choice A (Carbon) has 6 protons and usually has more neutrons than protons. Choice B (Oxygen) has 8 protons and 8 neutrons, so the numbers are not equal. Choice C (Lithium) has 3 protons and usually has more neutrons than protons, so it does not fit the criteria of having the same number of protons and neutrons.
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What is a group of organisms of the same species living in a particular area called?
- A. Community
- B. Population
- C. Ecosystem
- D. Habitat
Correct Answer: B
Rationale: A) Community refers to all the populations of different species living and interacting in a particular area. Since the question specifies organisms of the same species, community is not the correct answer. B) Population is a group of organisms of the same species living in a particular area. This term specifically refers to individuals of the same species and their interactions within a defined area. C) Ecosystem includes all the living organisms (biotic factors) and non-living components (abiotic factors) in a particular area and their interactions. While populations are part of an ecosystem, the term 'ecosystem' is broader and includes multiple populations. D) Habitat refers to the specific environment where an organism lives, including the physical and biological factors. It is the place where a population or individual organism resides, but it does not specifically refer to a group of organisms of the same species.
What is the outermost protective layer of the kidney?
- A. Renal cortex
- B. Renal medulla
- C. Renal capsule
- D. Renal pelvis
Correct Answer: C
Rationale: The correct answer is C, Renal capsule. The renal capsule is the outermost protective layer of the kidney. It is a tough fibrous layer that surrounds the kidney and helps protect it from injury and maintain its shape. Choice A, Renal cortex, is the outer region of the kidney where filtration occurs. Choice B, Renal medulla, is the inner region of the kidney where urine is formed. Choice D, Renal pelvis, is the funnel-shaped structure that collects urine from the kidney and funnels it into the ureter. Therefore, the renal capsule is specifically designated as the outermost protective layer of the kidney.
What are the three main types of RNA?
- A. Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
- B. DNA, RNA, and protein
- C. Adenine, guanine, cytosine, and thymine
- D. Deoxyribose, ribose, and phosphate
Correct Answer: A
Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis.
- Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis.
- Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis.
Options B, C, and D are incorrect:
- Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA.
- Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA.
- Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic
Which of the following is the main organ responsible for producing bile?
- A. Liver
- B. Gallbladder
- C. Pancreas
- D. Stomach
Correct Answer: A
Rationale: The liver is the main organ responsible for producing bile. Bile, a greenish-yellow fluid, is produced by the liver and stored in the gallbladder. Its primary function is to aid in the digestion and absorption of fats in the small intestine. When needed, the gallbladder releases bile into the small intestine to facilitate fat digestion. The pancreas produces digestive enzymes and insulin, not bile, making choice C incorrect. The stomach's primary role is to digest food through gastric juice secretion, making choice D incorrect. Therefore, the correct answer is the liver, as it is the main organ responsible for bile production.
What is the unit of measurement for momentum?
- A. Newton-second (N·s)
- B. Kilogram-meter (kg·m)
- C. Joule (J)
- D. Meter per second (m/s)
Correct Answer: A
Rationale: The correct unit of measurement for momentum is Newton-second (N·s). Momentum is calculated as the product of an object's mass and its velocity. The unit of mass is kilograms (kg) and the unit of velocity is meters per second (m/s). Therefore, the unit of momentum is kilogram-meter per second (kg·m/s). By Newton's second law of motion (F = ma), force is measured in Newtons (N), which is equivalent to kg·m/s². Multiplying the unit of force (N) by the unit of time (s) gives the unit of momentum as Newton-second (N·s). Choice B, Kilogram-meter (kg·m), is incorrect because it represents the unit of work or energy, not momentum. Choice C, Joule (J), is incorrect as it is a unit of energy. Choice D, Meter per second (m/s), is incorrect as it represents velocity alone, not momentum which is a vector quantity involving mass and velocity.