Biology: Samples -

Set 1, Slide 80, Cross Section, Lightfield

Pine

Cone
Leaf
Root
Stem

Root

Ipomoea
Mitosis Onion
Pine
Meristem
Zea
Zea Root Tip

A cross-section of pine root seems to have many tiny holes. These holes are speculated to be water pipes of the root. The root is generally divided into three layers: pith, xylem, and cortex layer.

Wayne's Word provides a detailed diagram of a pine root.

Pith

Pith layer is most inner layer of those three layers in the pine root. Pith layer is consisted of many holes. These holes seem to be circular, and some of these holes are filled with greenish substances.

Image	Data	Description
	200x	The center of the pine root seems to be empty. The holes that comprise the pith layer appear to be circular.
	400x	Some of the holes look like filled with greenish substances. These substances seem to have little bit rough texture.

Xylem

Xylem is the middle layer. Xylem layer contains many gigantic holes that are speculated to be water pipes of the root. The edge of the holes are red. In addition, rays, or lines that appear on the layer, are found in this layer. Small holes that comprise the layer seems to be ellipse rather than circular.

Image	Data	Description
	200x	These circular holes seem to be water pipes. Interestingly, the edge of these holes is red.
	400x	There is a distinct line that goes cross the xylem layer. This line is called ray. The ray seems to be filled with greenish substances so that they appear darker and distinct.

Cortex

Cortex is the most outer layer. Epidermis of the root touches the cortex layer. Holes that comprise the cortex layer now seem to be rectangular. Resin ducts are found on the layer. Resin ducts appear like dark dusts that sticking on the layer.

Image	Data	Description
	100x	The holes appear to be rectangular, and most holes seem to be filled with greenish substances. The epidermis of the root appears in the image.
	400x	These are closed-up of resin ducts. These two resin ducts appear to be dark look slightly similar to a bunch of frog's eggs.

Touchspin Biology

Pith

Xylem

Cortex