Science Worksheet (Set 12)
Topic: Respiration
Grade: VII
Q1. Answer the following questions:
a. Explain how goldfish extract oxygen from water using their gills.
– Goldfish take in water through their mouths.
– The water passes over the gill filaments, which have many blood vessels.
– Oxygen from the water diffuses into the bloodstream through the thin walls of the gills, while carbon dioxide is expelled.
– The water passes over the gill filaments, which have many blood vessels.
– Oxygen from the water diffuses into the bloodstream through the thin walls of the gills, while carbon dioxide is expelled.
b. What environmental conditions are necessary for effective gas exchange in an earthworm through its skin?
– Moist skin to allow oxygen diffusion.
– Oxygen-rich soil for effective respiration.
– Low pollution levels to prevent clogging of skin pores.
– Oxygen-rich soil for effective respiration.
– Low pollution levels to prevent clogging of skin pores.
c. How does air reach the tissues after entering the lungs from the Bronchus?
– Air moves from the Bronchus → Bronchioles → Alveoli.
– In the alveoli, oxygen diffuses into the capillaries and enters the bloodstream.
– Carbon dioxide moves from the blood into the alveoli and is expelled during exhalation.
– In the alveoli, oxygen diffuses into the capillaries and enters the bloodstream.
– Carbon dioxide moves from the blood into the alveoli and is expelled during exhalation.
d. Imagine you are a scientist studying yeast. If you placed yeast in an environment with little oxygen, what type of respiration would occur? What would be the result of this process?
– Yeast would undergo anaerobic respiration due to the lack of oxygen.
– This process would result in the production of less energy, alcohol (ethanol), and carbon dioxide (CO₂).
– This process would result in the production of less energy, alcohol (ethanol), and carbon dioxide (CO₂).
e. Why are the lungs divided into smaller structures like lobes and alveoli rather than being one large sac?
– Increases surface area for better absorption of oxygen.
– Allows efficient gas exchange for different parts of the body.
– Allows efficient gas exchange for different parts of the body.
f. Analyze why high-altitude training is beneficial for athletes, particularly in terms of respiration.
– At high altitudes, there is less oxygen in the air.
– The body produces more red blood cells to carry oxygen efficiently.
– Over time, this improves blood oxygenation, enhancing endurance and stamina.
– The body produces more red blood cells to carry oxygen efficiently.
– Over time, this improves blood oxygenation, enhancing endurance and stamina.
g. A certain population of bacteria is thriving in a low-oxygen environment. What type of respiration are they likely using? Discuss the advantages of this type of respiration in that specific environment.
– These bacteria are using anaerobic respiration, which does not require oxygen.
– Advantages:
– Can function in oxygen-deficient areas.
– Allows energy production even without oxygen.
– Produces byproducts like alcohol or lactic acid, which some organisms use for survival.
– Advantages:
– Can function in oxygen-deficient areas.
– Allows energy production even without oxygen.
– Produces byproducts like alcohol or lactic acid, which some organisms use for survival.