Science

Science Related

Review Science related questions and content

Which of the following characteristics of water helps explain why coastal areas experience less dramatic temperature changes during the day than more inland areas?

  • A. Water's adhesive properties prevent evaporation.
  • B. Water is a versatile solvent.
  • C. Water has a high specific heat capacity.
  • D. Water forms covalent bonds with other water molecules.
Correct Answer: C

Rationale: The correct answer is C. Water has a high specific heat capacity, meaning it can absorb and store a large amount of heat energy before its temperature rises significantly. This characteristic allows water to moderate temperature changes by absorbing heat during the day and releasing it slowly at night, resulting in less dramatic temperature fluctuations along coastal areas compared to inland areas. Water's adhesive properties (choice A) do not directly contribute to moderating temperature changes. While being a versatile solvent (choice B) is a notable property of water, it is not the primary reason for the specific temperature moderation observed in coastal areas. Water forming covalent bonds with other water molecules (choice D) is more related to its molecular structure rather than its role in temperature moderation.

You may also like to solve these questions

What is the approximate threshold value for mammalian neurons?

  • A. -80 mV
  • B. -55 mV
  • C. 0 mV
  • D. +35 mV
Correct Answer: B

Rationale: The approximate threshold value for mammalian neurons is around -55 mV. At this membrane potential, the neuron becomes more excitable and is more likely to generate an action potential. If the membrane potential reaches this level or depolarizes beyond it, it triggers the opening of voltage-gated ion channels, leading to the initiation of an action potential. Values below this threshold are considered subthreshold and do not usually result in action potential generation. Understanding the threshold potential is crucial in assessing the excitability and firing properties of neurons, as it represents the critical point at which the neuron transitions from a resting state to an active state, enabling the transmission of electrical signals.

Which of the following organelles is the site of intracellular digestion?

  • A. Ribosomes
  • B. Lysosomes
  • C. Centrosomes
  • D. Mitochondria
Correct Answer: B

Rationale: Lysosomes are the organelles responsible for intracellular digestion within the cell. These specialized vesicles contain various enzymes that break down different molecules, such as old cell components or foreign substances. This breakdown process aids in cellular maintenance, recycling of materials, and waste elimination. Ribosomes are primarily involved in protein synthesis, centrosomes are essential for cell division processes, and mitochondria are the powerhouses of the cell, producing energy in the form of ATP. Therefore, the correct answer is B, Lysosomes, as they are specifically designed for intracellular digestion.

What action would result in an increase in the rate of a chemical reaction?

  • A. Adding more of the reactants
  • B. Decreasing the temperature of the reactants
  • C. Using a mortar and pestle to grind a solid reactant to a powder
  • D. Sealing the reaction in an airtight container
Correct Answer: C

Rationale: Grinding a solid reactant to a powder increases the surface area exposed to other reactants, leading to more frequent collisions and a faster reaction rate. This process enhances the chances of successful collisions, hence accelerating the reaction. The other options do not directly impact the rate of a chemical reaction in the same manner. Adding more of the reactants provides more reactant particles to collide, promoting a higher reaction rate. Decreasing the temperature of the reactants generally slows down reactions by reducing the kinetic energy of the particles. Sealing the reaction in an airtight container may affect the equilibrium but not necessarily the reaction rate.

Which of the following macromolecules forms the cytoskeleton of a cell?

  • A. Proteins
  • B. Carbohydrates
  • C. Nucleic acids
  • D. Lipids
Correct Answer: A

Rationale: The correct answer is Proteins (Choice A). The cytoskeleton of a cell is primarily composed of proteins. Proteins such as actin, tubulin, and intermediate filaments form the structural framework of the cytoskeleton, providing support, shape, and aiding in cellular movement. Carbohydrates, nucleic acids, and lipids do not constitute the cytoskeleton; instead, they serve various functions within the cell. Therefore, understanding the composition of the cytoskeleton is crucial for comprehending cellular structure and function.

What is the primary function of centrosomes in animal cells?

  • A. Pathogen digestion
  • B. Cytoplasm formation
  • C. Organelle trafficking
  • D. Microtubule organization
Correct Answer: D

Rationale: Centrosomes play a crucial role in animal cells by organizing microtubules. They act as the main microtubule organizing center (MTOC) and are essential for various cellular processes such as cell division, cell shape maintenance, and intracellular transport. Correctly organized microtubules are vital for maintaining cell structure and function, making option D, 'Microtubule organization,' the correct answer.

Copyright © 2025 Nokea. All rights reserved.