Reference

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobooktoc.html

http://www.biology.arizona.edu/

http://www.sciencedaily.com/news/plants_animals/evolution/

Parasitism, Commensalism, and Mutualism

•Mutualism is a biological interaction between two organisms, where each individual derives a fitness benefit.
An example - a bees polinate trees -- the bee gets food, the tree gets pollinated.

•Commensalism is the relation between two different kinds of organisms when one receives benefits from the other without damaging it.
An example -a flatworm attaching to the horsecrab and eating the crab's food while the crab is unaffected.

•Parasitism is the relation between two different kinds of organisms in which one receives benefits from the other by causing damage to it.
An example -a flea and a dog; flea gets home/food and the dog is harmed because the flea feeds on its blood

Four Organic Compounds

Lipids

• molecules composed of carbon, hydrogen and oxygen
• lipids include steroids, waxes, and fat
• the enzyme lipase breaks down fats into falty acids and glycerol in the human digestive system

Protein

• proteins are composed of amino acidswhich contain carbon, hydrogen, oxygen and nitrogen atoms
• amino acids also contain sulfur phosphorous, iron and copper

Nucleic Acids

• large molecules
• composed of smaller units called nucleotides
• live organisms have 2 important nucleic acids DNA or RNA

Carbohydrates

• molecules composed of carbon, hydrogen and oxygen
• referred to as sugars
• C6H12O6

Evidence for Evolution

Science does this by continuously comparing its theories objectively with evidence in the natural world. When theories no longer conform to the evidence, they are modified or rejected in favor of new theories that do conform. In other words, science constantly tries to prove its assumptions to be false and rejects implausible explanations. In this way, scientific knowledge and understanding grow over time. Religious explanations for the order of things are not science because they are based primarily on faith and do not subject themselves to be objectively falsified. Because of this fundamental difference in the approach to understanding our natural world, the U.S. Supreme Court in effect decided in 1987 that the Biblically based "creation science" is not a science and cannot be taught as such in public schools as an alternative or in addition to the mainstream evolutionary theory of the biological sciences. However, religious creation stories and the idea of "intelligent design" can be taught in philosophy, religion, or history courses. Religion and Science provide different approaches to knowledge. It is important to understand both.

The evidence for evolution has primarily come from four sources:

1.	the fossil record of change in earlier species
2.	the chemical and anatomical similarities of related life forms
3.	the geographic distribution of related species
4.	the recorded genetic changes in living organisms over many generations

Natural selection

Natural Selection is when a living thing is born with something different than the rest of their species (more fur, longer neck or legs, ect) that gives them an advantage and helps them live better and longer in their enviroment. They pass it onto their children and their children pass it onto their children making a different species.
*the rat snake has different populations in eastern North America. All compromise one specie because mating can occur between adjacent populations causing to share a common genepool.
**are well documented both by obsserving and through the fossil record!**

Darwin's Theory Vs. Lamarck's Ideas Of Evolution

Jean-BaptisteLamarck proposed that organisms could pass on to their offspring traits that where acquired during their lifetime. This has come to be known as inheritance of acquired characteristics.

On the other hand Charles Darwin recognized the main mechanism for evolution: Natural Selection. Natural Selection is the process by which favorable heritable traits become more common in successive generations of a population and unfavorable heritable traits become less common, due to differential reproduction. That is: given a certain population, those individuals who are more fit to the selective pressure(s) by their habitat (in a given time and space) will leave more descendants than those less fit

In short, Lamarck thought that changes were acquired during the life of a parent organism and then transmitted to their offspring while Darwin deducted that changes were already present in the parent organisms, and that the best adapted to that situation survived to breed, which meant that those genetic changes become common in the following generations

Read more: http://wiki.answers.com/Q/What_are_the_differences_between_Darwin's_theory_of_Evolution_and_Lamarck's_theory_of_Evolution#ixzz1VijtrisN

Phloem Vs. Xylem

	Phloem	Xylem	Hide AllShow All
Occurrence:	Roots, stems and leaves	Roots, stems and leaves	hide
Additional Functions:	Forms vascular bundles with xylem	Forms vascular bundles with phloem and gives mechanical strength to plant due to presence of lignified cells.	hide
Elements:	Sieve tubes, companion cells, phloem parenchyma, bast fibers, intermediary cells	Tracheids, vessel elements, xylem parenchyma, xylem sclerenchyma	hide
Nature of tissue:	Living tissue	Non living tissue at maturity	hide
Movement:	Bidirectional	Unidirectional (upward)	hide
Function:	Transportation of food and nutrients from leaves to storage organs and growing parts of plant.	Water and mineral transport from roots to aerial parts of the plant.	hide
Structure:	Tubular with soft walled cells	Tubular with hard walled cells	hide

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Phloem and xylem are complex tissues that perform transportation of food and water in a plant. They are the vascular tissues of the plant and together form vascular bundles. They work together as a unit to bring about effective transportation of food, nutrients, minerals and water.

[edit] Sap components

Xylem sap contains water, inorganic ions and a few organic chemicals. Phloem sap contains water and sugars.

Differences between Xylem and Phloem vessels

 Functions of xylem vs phloem

Xylem transports water and soluble mineral nutrients from roots to various parts of the plant. It is responsible for replacing water lost through transpiration and photosynthesis. Phloem translocates sugars made by photosynthetic areas of plants to storage organs like roots, tubers or bulbs.

 

 Video

This video explains the biological makeup of xylem and phloem and their role in plant transport.