Bio topic 3

• What is the relationship between surface area and volume in organisms?

  Larger organisms have a lower surface area to volume ratio
• Why do larger organisms need adaptations for gas exchange?

  They have higher metabolic needs and lower ratios
• What are some key adaptations for gas exchange in organisms?

  • Villi and microvilli in intestines
  • Alveoli and bronchioles in mammals
  • Spiracles and tracheae in insects
  • Gill filaments and lamellae in fish
  • Stomata in plants
• What is the definition of breathing?

  Movement of air in and out of lungs
• How does gas exchange differ from respiration?

  Gas exchange is diffusion; respiration is a reaction
• What are the key structures of the human gas exchange system?

  Alveoli, bronchioles, bronchi, trachea, lungs
• What role does the diaphragm play in ventilation?

  It contracts to increase thoracic volume
• What does the term antagonistic muscles mean?

  One muscle contracts while the other relaxes
• What happens during inhalation in terms of muscle action?

  External intercostal muscles contract, diaphragm lowers
• What occurs during exhalation?

  Internal intercostal muscles contract, diaphragm relaxes
• What is the formula for pulmonary ventilation?

  Tidal volume times ventilation rate
• What is the unit for measuring pulmonary ventilation?

  Decimeters cubed per minute
• What is the role of alveoli in gas exchange?

  They facilitate diffusion between air and blood
• How many alveoli are in each lung?

  Around 300 million
• Why do terrestrial insects face challenges in gas exchange?

  They have a waterproof exoskeleton
• What is the function of spiracles in insects?

  They allow gas exchange with the environment
• What is the tracheal system in insects?

  A network of tubes for gas exchange
• How do gases move in the tracheal system?

  By diffusion and mass transport
• What is the counter current flow mechanism in fish gills?

  Water flows opposite to blood in capillaries
• What are the three features of effective gas exchange surfaces?

  Large surface area, short diffusion distance, concentration gradient
• What adaptations do fish gills have for gas exchange?

  Large surface area and short diffusion distance
• What is the role of palisade mesophyll in leaves?

  Site of photosynthesis in plants
• How do stomata function in gas exchange?

  They allow gases to diffuse in and out
• When do stomata typically close?

  At night when it's dark
• What is the relationship between stomata and photosynthesis?

  Stomata open for gas exchange during photosynthesis
• What are the adaptations of terrestrial insects for gas exchange?

  • Large number of fine tracheals
  • Thin walls for short diffusion distance
  • Spiracles can open and close
  • Maintain steep concentration gradient
• What adaptations do fish have for gas exchange?

  • Gills with large surface area
  • Short diffusion distance due to capillaries
  • Counter current flow mechanism
• What are the key features of gas exchange surfaces?

  • Large surface area
  • Short diffusion distance
  • Mechanism to maintain concentration gradient
• Why is there always a higher concentration of oxygen in water compared to blood?

  Because wings move in opposite directions
• What is the main function of the palisade mesophyll in leaves?

  Photosynthesis
• What role do stomata play in leaves?

  They allow gases to diffuse in and out
• When do stomata close to reduce water loss?

  At night when it's dark
• What adaptations do xerophytic plants have to minimize water loss?

  They have rolled leaves and sunken stomata
• What is the purpose of the thicker cuticle in xerophytic plants?

  To reduce water loss
• How do adaptations in marum grass help reduce water loss?

  Leaves roll up and hairs trap moisture
• What happens to large biological molecules during digestion?

  They are hydrolyzed into smaller soluble molecules
• Which three biological molecules are primarily digested?

  Carbohydrates, lipids, and proteins
• Where does carbohydrate digestion begin?

  In the mouth
• What enzyme is produced by the salivary gland for carbohydrate digestion?

  Amylase
• What is the role of amylase in carbohydrate digestion?

  It hydrolyzes polysaccharides into disaccharides