Science

Science Related

Review Science related questions and content

Which term describes the relaxation of the chambers of the heart during the cardiac cycle?

  • A. Tachycardia
  • B. Diastole
  • C. Systole
  • D. Bradycardia
Correct Answer: B

Rationale: During the cardiac cycle, diastole represents the relaxation phase of the heart chambers. In diastole, the heart muscles relax, allowing the chambers to fill with blood. Tachycardia and bradycardia are terms used to describe heart rate abnormalities, while systole refers to the contraction phase of the heart when blood is pumped out of the chambers. Understanding the different phases of the cardiac cycle is crucial in comprehending how the heart functions to pump blood effectively. Diastole plays a vital role in ensuring that the heart chambers are adequately filled with blood before the next contraction phase, systole, propels the blood out to the rest of the body. This coordination between diastole and systole is essential for maintaining proper cardiac function and circulation.

You may also like to solve these questions

What type of tissue largely makes up the pharynx?

  • A. Bone
  • B. Muscle
  • C. Nervous
  • D. Cartilage
Correct Answer: B

Rationale: The pharynx is mostly composed of muscle tissue, which enables it to carry out functions like swallowing and breathing. Muscles in the pharynx contract to propel food into the esophagus during swallowing and aid in vocalization and respiration.

What scientific purpose does an experienced mountaineer serve by deciding to climb Mount Everest, following the same route, season, and using similar materials and equipment as a fatal 1924 expedition?

  • A. To identify routes for future climbs
  • B. To demonstrate that modern technology enhances climbing safety
  • C. To measure oxygen levels at high altitudes
  • D. To assess why the earlier expedition failed
Correct Answer: D

Rationale: The scientific purpose of the experienced mountaineer climbing Mount Everest using the same route, season, and equipment as the 1924 expedition is to assess why the earlier expedition failed. By replicating the conditions of the failed expedition, the mountaineer aims to study the factors that led to its failure, potentially providing valuable insights for future expeditions and safety improvements. This approach allows for a critical analysis of the past expedition's shortcomings, contributing to greater knowledge and safety measures in mountaineering.

What is the function of a totipotent cell?

  • A. Fights infection
  • B. Develops into any type of cell
  • C. Aids in the maturation of sex cells
  • D. Carries electrical impulses
Correct Answer: B

Rationale: Totipotent cells possess the remarkable ability to differentiate into any cell type in the body, encompassing both embryonic and extraembryonic cell varieties. This quality is crucial in the early stages of embryonic development, facilitating the generation of all cell lineages and tissues. Unlike pluripotent or multipotent cells, totipotent cells exhibit the most extensive differentiation potential, playing a vital role in the organism's development from a single fertilized egg cell.

Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?

  • A. Carbon Monoxide
  • B. Oxygen
  • C. Carbon Dioxide
  • D. Carbonic Acid
Correct Answer: D

Rationale: Carbonic acid is a pivotal buffer in blood that plays a key role in maintaining pH balance. When blood pH rises, indicating increased alkalinity, carbonic acid releases hydrogen ions (H+) to counterbalance the excess base, thereby preventing significant changes in pH levels. This mechanism highlights the essential function of carbonic acid in regulating the acid-base equilibrium in the blood.

Which of the following is an example of a biological macromolecule?

  • A. Monosaccharide
  • B. Protein
  • C. Nucleic acid
  • D. Amino acid
Correct Answer: B

Rationale: The correct answer is B, 'Protein.' Proteins are biological macromolecules composed of amino acid chains. They play vital roles in cellular functions, including catalyzing reactions, providing structural support, and acting as signaling molecules. Monosaccharides are simple sugars, nucleic acids are genetic materials such as DNA and RNA, and amino acids are the fundamental units that make up proteins.

Copyright © 2025 Nokea. All rights reserved.