Environmental Engineering Reference
In-Depth Information
TABLE 5.3
Main Phyla (Divisions) of Plants
Phylum
(Division)
Examples
Bryophyta
Mosses, liverworts, and hornworts
Coniferophyta
Conifers such as redwoods, pines, and firs
Cycadophyta
Cycads, sago palms
Gnetophyta
Shrub trees and vines
Ginkophyta
Ginkgo
(the only genus)
Lycophyta
Lycopods (look like mosses)
Pterophyta
Ferns and tree-ferns
Anthophyta
Flowering plants, including oak, corn, maize, and herbs
Vascular tissue
is found in the bodies of vascular plants that transport water,
nutrients, and carbohydrates. The two major kinds are xylem and phloem.
Xylem
is vascular tissue of plants that transports water and dissolved minerals
from the roots upwards to other parts of plant. Xylem often also provides
mechanical support against gravity.
Although not typically acknowledged, plants are as intricate and complicated as
animals. Plants evolved from photosynthetic protists and are characterized by photo-
synthetic nutrition, cell walls made from cellulose and other polysaccharides, lack of
mobility, and a characteristic life cycle involving an alternation of generations. The
phyla (divisions) of plants and some examples are shown in Table 5.3.
p
lant
c
ell
A brief summary of plant cells is provided here (see
Figure 5.4
).
•
Plants have all the same organelles that animal cells have
(e.g., nucleus,
ribosomes, mitochondria, endoplasmic reticulum, Golgi apparatus).
•
Plants have chloroplasts
, the special organelles that contain chlorophyll
and allow plants to carry out photosynthesis.
•
Plant cells can sometimes have large vacuoles for storage
.
•
Plant cells are surrounded by a rigid cell wall made of cellulose,
in addi-
tion to the cell membrane that surrounds animal cells. These walls provide
support.
DID YOU KNOW?
In the Pacific Northwest and Oregon, biomass energy costs are about 5.2 to
6.7 cents per kWh. This is comparatively costlier than the electricity generated
from natural gas, which is only 2.8 cents per kWh (Karthik, 2010).
