表皮
anatomy
background
biological
biology
botanic
botanical
botany
cell
chlorophyll
chloroplast
closed
dioxide
discovery
education
experience
green
guard
laboratory
leaf
life
living
macro
micro
microbiology
microscope
microscopic
nature
nucleus
o2
observation
open
oxygen
pathology
photosynthesis
plant
pore
preparation
process
research
respiration
science
scientific
stigma
stoma
stomata
structure
tissue
vacuole
wall