What does it mean to say "ferns are green plants"?

Ferns are green plants with leaves, often called fronds, that resemble fiddleheads in spring before they unroll.

Explanation:

see below

Explanation:

Ferns are green plants with leaves, often called fronds, that resemble fiddleheads in spring before they unroll. ... The stem of this plant is jointed with scalelike leaves growing in whorls.Ferns are green flowerless plants with divided leaves that tend to grow in damp, shady areas. The developing leaves of most ferns uncoil from a koru. Ferns are an ancient group of plants. By about 350 million years ago, ferns are seen in the fossil record

all matter is made up of atoms

in any element all atoms are the same

elements in a compound are always in a constant ratio: apex

when it is at an intermediate population density