http://www.ck12.org Chapter 10. Understanding Biodiversity: Plants
Description
Toxicodendron diversilobum, or poison oak, can both grow as a shrub and a vine. It’s leaves are made of three leaflets
with small teeth on each of the leaflets. They are two to six feet in height. If it gets hold of a sapling, or new tree, it
could possibly kill it. When you touch it, the sap from it gets on your skin, eventually causing an allergic reaction
that feels like a stinging sensation. It takes 100 nanograms of the allergen urushiol to get a reaction in more sensitive
people. Also, this plant, as well as poison ivy, cause very painful reactions. So it’s a good idea not to touch poison
ivy or poison oak, and especially to be careful in areas such as abandoned mines, forests, near rivers, ghost towns,
and abandoned fields, which is where they flourish. The plant blooms in March and April.
The complete taxonomic classification is:
- Kingdom: Plantae
- Phylum: Magnoliophyta
- Class: Magnoliopsida
- Order: Sapindales
- Family: Anacardiaceae
- Genus:Toxicodendron
- Species:T. diversilobum
Habitat
Western poison oak appears at the southwestern point of Canada, stretching down through the Pacific Coast down to
Baja California. They grow in moist soil with plenty of sunlight in elevations below 1,650m. There are some other
sightings of western poison oak in other regions of California and some unregistered sightings of western poison
oak in Nevada.
Biology
Cell Biology
As a member of the Kingdom Plantae,T. diversilobumis made of eukaryotic cells. The cells ofT. diversilobum
have a protective barrier called the plasma membrane. They are also made of many organelles, structures like small
organs that help the cell function. The nucleus contains the DNA with instructions for the cell, making it a eukaryotic
cell. mRNA is produced by the nucleus, and ribosomes translate mRNA into proteins. The mitochondria produces
ATP (adenosine trisphosphate), which powers the cell. Vesicles transport materials within the cell or outside the
cell. Lysosomes, a type of vesicle, take all the waste from the cell and takes it away. Endoplasmic reticulum is split
into two parts, the rough endoplasmic reticulum and the smooth endoplasmic reticulum. The rough endoplasmic
reticulum has ribosomes attached to it which create proteins that are released inside of the endoplasmic reticulum.
It is then sent to the Golgi apparatus. The smooth endoplasmic reticulum creates lipids. The Golgi apparatus tells
where the proteins from the endoplasmic reticulum where to go. The cytoskeleton gives the cell it’s shape. SinceT.
diversilobumis a plant, it has a couple of extra organelles. One is a large, central vacuole that stores the cell’s water
and nutrients. The cell wall acts as extra protection in addition to the plasma membrane and provides structure.
Chloroplasts make the plant green and allow for photosynthesis.
T. diversilobumcells divide by mitosis, where the nucleus divides, and the new cells have the same chromosomes
(they are genetically identical) as their parent. Another way that cells divide is through meiosis, where the new cells