GCSE Biology (AQA)

331 videos | 14 hours

Investigating Stomata

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Organisation Plant Tissues, Organs and Systems

Investigating Stomata

3:07 Plant Leaf Structures
Spec 4.2.3.2
Previous Stomata & Guard Cells Next Xylem
  • Microscopes can be used to investigate if guard cells are closing or opening stomata.
  • Visual differences in stomata can be observed through a microscope's eyepiece when they are open versus when they are closed.
  • Additional explorations can include comparing the distribution of stomata on the undersides of leaves from different plants.
  • Plants adapted to hot, dry, or windy conditions have a different stomatal distribution to conserve water.
  • Plants in temperate climates have more stomata to allow greater gas exchange without excessive water loss.
  • The number of stomata in a given area can be calculated using a micrometer scale on a microscope eyepiece.
  • To determine stomatal density, count the number of stomata in a known area and then calculate for the area of interest.
  • Example calculation: If there are 18 stomata in 0.2 mm��, to find the number in 0.1 mm��, multiply 18 by the ratio of the areas (0.1/0.2 = 5), resulting in 90 stomata per 0.1 mm��.
  • Understanding stomatal distribution involves counting visible stomata in a known area and adjusting for different areas using multiplication.

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