Answer:
Cell biology is a branch of biology that studies the structure, function and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of organisms. Cell biology is the study of structural and functional units of cells.
It comes from a unicellular organism named Chloroplast that produces a green pigment substance called chlorophyll, this where oxygen is produced as a by-product of photosynthesis.
Low pressure- Where the air pressure is below average
High pressure- Where the air pressure is above average
The one in my opinion that best describes a leaf is tissue. it can't be the organism because that would be the tree itself. In a like fashion, it can't be the organ because the branches of the tree would be the organs. Since the leaves make up the branches... they would be tissues.
