B2.8 Surface to volume ratio

• What concept is explained in this video?

  Surface area to volume ratio
• Why can single-celled bacteria rely on diffusion?

  They have a high surface area to volume ratio
• What do large multicellular organisms require for substance exchange?

  Specialized exchange surfaces and transport systems
• What resources do single-celled organisms need to absorb?

  Oxygen, glucose, and amino acids
• What waste products do single-celled organisms need to eliminate?

  Carbon dioxide
• What does the surface area to volume ratio measure?

  Surface area compared to volume
• How does the surface area to volume ratio change as organisms get larger?

  It decreases as organisms grow larger
• What is the surface area of a 1 cm cube?

  6 square centimeters
• What is the volume of a 1 cm cube?

  1 cubic centimeter
• What is the surface area to volume ratio of a 1 cm cube?

  6 to 1
• What is the surface area of a medium cube with a volume of 8 cm³?

  24 square centimeters
• What is the volume of a medium cube?

  8 cubic centimeters
• What is the surface area to volume ratio of the medium cube?

  3 to 1
• What is the surface area of the largest cube?

  54 square centimeters
• What is the volume of the largest cube?

  27 cubic centimeters
• What is the surface area to volume ratio of the largest cube?

  2 to 1
• Which organisms have a larger surface area to volume ratio? 

  Small organisms
• How does the increase in size affect the surface area and volume of cubes?

  Volume increases faster than surface area
• Why can't humans rely solely on diffusion?

  We have a low surface area to volume ratio
• What specialized exchange surfaces do humans have?

  Lungs and intestines
• What do alveoli in the lungs provide?

  A huge surface area for gas exchange
• What do villi in the intestines provide?

  A massive surface area for nutrient absorption
• How does diffusion distance change in larger organisms?

  It increases significantly
• How far do molecules diffuse in bacteria?

  About one micrometer
• How far do molecules diffuse in humans?

  At least 5 centimeters
• Why do larger organisms need transport systems?

  To transport molecules efficiently around the body
• What do plants use for substance exchange?

  Roots and leaves
• What tissues do plants use to transport substances?

  Phloem and xylem
• What does the term "large organisms" refer to?

  Anything visible to the naked eye
• Who is the presenter of the video?

  Amadeus
• What does the learning platform offer?

  Videos, practice questions, and progress tracking
• Is the learning platform free?

  Yes, it's completely free
• Where can you find the link to the lesson?

  In the description below the video
• What is the purpose of the playlist mentioned?

  To organize all videos for the subject
• What is the main aim of this video?

  To explain the need for exchange surfaces
• Give two examples of exchange surfaces in humans and describe their function.

  • Example 1 - Alveoli (or lungs)

  > Alveoli allow oxygen and carbon dioxide to diffuse in and out of the body/bloodstream 

  • Example 2 - Villi (or small intestines)

  > Villi allow nutrients such as glucose, amino acids, mineral ions etc to be absorbed from the small intestines into the bloodstream