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The Pressure Flow Model in a Plant

By: HWC, Views: 6025

The vascular system of plants has two transport tissues, called xylem and phloem. Xylem transports water and minerals, while phloem transports a variety of dissolved substances, including sugars and amino acids, throughout the plant. Water in the xylem always moves up, in the direction from th...

Pressure Flow Model Animation

By: HWC, Views: 5867

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...

Monohybrid crosses

By: HWC, Views: 4461

A monohybrid cross is a cross between two parents that breed true for different versions of a single trait. In this example, that trait is flower color. The allele that specifies purple flowers is dominant over the allele that specifies white flowers. The purple-flowered plant has two domin...

Photosynthesis and Van Helmont Experiment

By: HWC, Views: 5942

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

What are the Parts of a Plant Cell?

By: HWC, Views: 5702

Every chloroplast in a plant cell is packed with stacks of flattened sacs called thylakoids. The thylakoid membranes contain chlorophyll, as well as most of the other components required for the light reactions of photosynthesis. The chlorophyll-containing structures within the membranes are c...

Fractures Animation

By: Administrator, Views: 9638

Types of fractures: - Colles' - Pott's - Compression - Vertebral compression - Epiphyseal - Stress - Hip Closed, or simple–A completely internal break that does not involve a break in the skin (x-ray of the tibia and fibula). Note the break in the fibula (smaller bone). Open, or co...

Vascular tissues in a corn stem and a buttercup root

By: HWC, Views: 1162

Vascular tissues in a corn stem and a buttercup root. The cells that make up each tissue. Xylem conducts water and dissolved ions. It also helps mechanically support a plant. The cells, called vessel members and tracheids, are dead at maturity. Their lignified walls interconnect and serve as p...

Polysaccharides

By: HWC, Views: 6215

More complex sugars are called polysaccharides (from "poly" meaning "many" and "saccharum" meaning "sugar"). Many things in nature are made of polysaccharides. Here we show one of the polysaccharides in corn, another in wood, and another in the exoskeletons of insects like grasshoppers. How are a...

Major Elements in Biological Molecules: Carbohydrates

By: HWC, Views: 6220

Carbohydrates include simple sugars (monosaccharides) as well as large polymers (polysaccharides). Glucose is a hexose, a sugar composed of six carbon atoms, usually found in ring form. A starch macromolecule is a polysaccharide composed of thousands of glucose units. Glucose molecules can be ...