Nokea
What is the term for the process of breaking a large molecule into smaller fragments by applying heat?
- A. Polymerization
- B. Hydrogenation
- C. Isomerization
- D. Pyrolysis
Correct Answer: D
Rationale: Pyrolysis is the correct answer. It is the process of breaking down large molecules into smaller fragments by applying heat in the absence of oxygen. This results in the decomposition of molecules into simpler compounds. Polymerization, the process of synthesizing large molecules from smaller units, is incorrect as it is the opposite process. Hydrogenation involves adding hydrogen atoms to a compound, usually with a catalyst, which is not related to breaking down large molecules. Isomerization refers to rearranging atoms within a molecule to form isomeric compounds with the same molecular formula but different structural arrangements, which is also unrelated to the process described in the question.
You may also like to solve these questions
What is the difference between homologous chromosomes and sister chromatids?
- A. Homologous chromosomes have the same genes but may have different alleles, while sister chromatids are identical copies of the same chromosome.
- B. Homologous chromosomes are only found in diploid cells, while sister chromatids are found in both haploid and diploid cells.
- C. Both homologous chromosomes and sister chromatids are genetically identical, but only sister chromatids separate during mitosis.
- D. Both homologous chromosomes and sister chromatids can separate during mitosis, but only homologous chromosomes have different alleles.
Correct Answer: A
Rationale: Rationale:
- Homologous chromosomes are pairs of chromosomes that have the same genes in the same order, one from each parent. While they carry the same genes, they may have different alleles (variants of a gene).
- Sister chromatids are exact copies of each other, formed during DNA replication. They are held together by a centromere and are produced during the S phase of the cell cycle.
- During meiosis, homologous chromosomes pair up and exchange genetic material through crossing over, leading to genetic variation. Sister chromatids separate during mitosis to ensure each daughter cell receives an identical copy of the genetic material.
What phenomenon is responsible for the creation of rainbows?
- A. Reflection only
- B. Diffraction
- C. Refraction and reflection
- D. Polarization
Correct Answer: C
Rationale: Rainbows are created by both refraction and reflection of sunlight within water droplets in the atmosphere. When sunlight enters a water droplet, it is refracted, then internally reflected, and finally refracted again as it exits the droplet. This process causes the separation of light into its component colors and the formation of a rainbow. Choice A is incorrect because rainbows are not solely formed by reflection. Choice B, diffraction, is not the primary phenomenon responsible for rainbows. Choice D, polarization, is not directly involved in the creation of rainbows. Therefore, the correct answer is C.
Which element shares the same group (family) on the periodic table with helium (He)?
- A. Neon (Ne)
- B. Boron (B)
- C. Carbon (C)
- D. Oxygen (O)
Correct Answer: A
Rationale: Neon (Ne) shares the same group (family) on the periodic table with helium (He). Both helium and neon belong to Group 18 (Noble Gases) due to their complete and stable outer electron shells, making them chemically inert. Boron (B), Carbon (C), and Oxygen (O) are not in the same group as helium. Boron is in Group 13, Carbon is in Group 14, and Oxygen is in Group 16 on the periodic table.
What is the term for the energy absorbed during a chemical reaction?
- A. Kinetic energy
- B. Potential energy
- C. Heat energy
- D. Endothermic energy
Correct Answer: D
Rationale: The correct term for the energy absorbed during a chemical reaction is 'Endothermic energy.' Endothermic reactions absorb energy from their surroundings, leading to a decrease in temperature. The prefix 'endo-' means 'inward' or 'within,' indicating that energy is taken in during the reaction. Choices A, B, and C are incorrect because kinetic energy refers to the energy of motion, potential energy is stored energy, and heat energy is a form of energy transfer rather than specifically the energy absorbed during a chemical reaction.
Scoliosis is a condition characterized by abnormal lateral curvature of the spine. Which part of the spine is most commonly affected?
- A. Cervical spine (neck)
- B. Thoracic spine (upper back)
- C. Lumbar spine (lower back)
- D. All of the above
Correct Answer: B
Rationale: Scoliosis most commonly affects the thoracic spine, which is the upper back region. While scoliosis can potentially affect any part of the spine, the thoracic spine is the most frequently involved area. This region is more commonly affected due to the natural structural curves of the spine and the biomechanics of the thoracic area. The cervical spine (neck) and lumbar spine (lower back) can also be affected by scoliosis, but the thoracic spine is the primary area of involvement in most cases. Therefore, the correct answer is B, as it is the part of the spine most commonly affected by scoliosis.