OpenLLM-France/wikimedia huggingface dataset:
# General Genetics/Splicing

Introns are intervening RNA sequences that do not code for proteins or serve other functions. They lie between coding regions of RNA known as exons. During eukaryotic mRNA processing, the introns are excised and exons are spliced together to form the mature mRNA transcript. One pre-mRNA can give rise to different mature mRNA transcripts through alternative or differential splicing, wherein the exons are spliced in different permutations.

## How Self-Splicing led to the RNA World Hypothesis

In the protozoan Tetrahymena, a rare form of "self-splicing" takes place wherein no proteins are required. The RNA folds into a secondary structure which excises introns. This was discovered by Tom Cech, who won the Nobel Prize in 1989 for his discovery of catalytic RNA.
The discovery of catalytic RNA led to the RNA World Hypothesis, which postulated that earlier forms of life may have relied solely on RNA to store genetic information and catalyze chemical reactions. However, many scientists believe that RNA is too unstable (due to its highly reactive 2'-OH group) to reliably give rise to life.

## The Lariat Model of Intron/Exon Splicing

Small nuclear ribonucleoproteins (snRNPs) are formed from a combination of small nuclear RNA (snRNA) and helper proteins. These join with other proteins to form a spliceosome assembly.
Pre-mRNA has guanine (G) nucleotides at the 5' side of its introns. Towards the middle of the intron is an adenine (A) nucleotide. The spliceosome will fold the intron such that the G and A are next to each other. The oxygen of the A's 2' hydroxyl group attacks the 5' phosphate of the G. The G detaches from the 3' end of the exon to form a loop with the A. The hydroxyl group at the 3' end of the newly-formed exon attacks the phosphate group at the beginning of the next exon. The intron lariat is completely excised from the mRNA.
# General Genetics/The Discovery of the DNA Molecule

In 1869, the Swiss biochemist Friedrich Miescher collected white blood cells from the pus on the nearby surgical clinic's used bandages. He was the first to separate the nuclei from the rest of the cell, which he accomplished by rinsing the cells many times with dilute (1:1000) hydrochloric acid at extremely cold temperatures. He later improved upon this protocol, using a solution of pepsin (a proteolytic enzyme present in stomach juices) and alcohol to degrade cytoplasmic proteins and lipids. He treated the isolated nuclei with an extremely dilute (1:100,000) sodium carbonate solution followed by hydrochloric or acetic acid to precipitate a novel substance he termed "nuclein." Upon the discovery of another nucleic acid (then termed "yeast nucleic acid") in 1909, nuclein's name was changed to "thymus nucleic acid." Eventually, thymus nucleic acid became known as deoxyribonucleic acid: DNA.
However, the working hypothesis in the scientific community was that proteins were the molecules responsible for the transmission of genetic information. After all, proteins are comprised of 20 different monomers (amino acids), whereas DNA is only comprised of 4 monomers (nucleotides). Therefore, proteins were seen as capable of conveying more complex information than nucleic acids.
In 1952, Alfred Hershey and Martha Chase used radioactive elemental isotopes to label T2 bacteriophages: one group was labelled with radioactive sulfur ($^{35}$S) and the other with radioactive phosphorus ($^{32}$P). Because protein (but not DNA) contains sulfur and DNA (but not protein) contains phosphorus, the $^{35}$S isotope marked the phages' proteins and the $^{32}$P marked only the phages' DNA. After allowing the labelled bacteriophages to infect E. coli cultures, Hershey and Chase found that the radioactive phosphorus was present inside of the bacteria -- but the sulfur was not. This indicated that genetic information in T2 was transmitted by DNA, not protein.
The next year, in 1953, James Watson and Francis Crick published a plausible double-helix configuration for DNA in the journal Nature, This theory relied on X-ray crystallography images of DNA taken by the physical chemist Rosalind Franklin.

## Sources

Sam Kean (2011) The Disappearing Spoon
# Horticulture/Mites

Mites :
| Type: | Arachnid |
| Order: | Acari |
| Metamorphosis: | Incomplete |
| Damaging stages: | All |
| Vulnerable stages: | All |
Mites, together with Ticks, belong to the subclass Acarina (also known as Acari) and the class Arachnida. Mites are among the most diverse and successful of all the invertebrate groups. They have exploited an incredible array of habitats, and because of their small size (some are microscopic) most go totally unnoticed. Many live freely in the soil or water, but many species live as parasites on plants or animals and some feed on mold.
Insects may also have parasitic mites. Examples are Varroa destructor which attaches to the body of the honeybee, and Acarapis woodi, which lives in the tracheae of honeybees. There are hundreds of species of mites associated with other bee species, and most are poorly described and understood. Some are thought to be parasites, while others beneficial symbionts.
There are over 45,000 described species of mites. Scientists believe that we have only found 5% of the total diversity of mites. Mites have existed for around 400 million years.
Most mites in the garden are pests, but some mites are predatory on other mites.

## Description

Mites are very small arthropods, with eight legs and two body segments. They have piercing-sucking mouthparts.

## Symptoms and Signs

Mite damage includes stippling, discoloration, distorted foliage, and in the case of spider mites webbing.

## Control

* Cultural controls: Most mites thrive in hot, dry conditions
* Physical removal: Water Blasting
* Organic pesticides: Horticultural Oil, Neem Oil
* Rust mite Aceria anthocoptes
* Flat mite Brevipalpus phoenicis
* Dust mite Dermatophagoides pteronyssinus
* Yellow mite Lorryia formosa
* Yellow mite Lorryia formosa
* Plant mites forming a reproductive colony
# Horticulture/Micro-biocontrols

Micro-biocontrols are organisms that can be employed by gardeners to control garden pests and plant diseases.
This page is a stub entry in Horticulture. Please see the Manual of Style for guidelines on how to expand it.
# Horticulture/Muhlenbergia schreberi

Nimblewill :
| Binomial: | Muhlenbergia schreberi |
| Type: | perennial |
| Conditions: | sun to medium shade, prefers moist soils |
| Vegetative Spread: | rhizomes, and roots off the stolons |
Nimblewill is a perennial grass that often grows as a weed of lawns.
# Horticulture/Mukdenia rossii

Mukdenia :
| Binomial: | Mukdenia rossii |
Mukdenia rossii is a clumping herbaceous plant native to woodlands in Eastern Asia, grown for its foliage and spring flowers.
# Horticulture/Modifying Soils for Control of Weeds

The appearance of certain weeds can often be used as an indicator of certain soil types or problems regarding nutrition, pH, structure, or organic content. In many cases, weeds can be controlled by modifying the soil.
This page is a stub entry in Horticulture. Please see the Manual of Style for guidelines on how to expand it.
# Horticulture/Mosses and Bryophytes
## Mosses and Bryophytes

Bryophytes (non-vascular land plants), of which the most well-known are mosses, but also include liverworts and hortworts, are an ancient form of plants, suited to some forms of gardening. For similar uses, see lichen.
Particularly useful in rock gardens.

## Examples

One of the most famous moss gardens is 苔寺 (koke dera, “moss temple”) of Saihō-ji, Kyoto.
See Moss#Cultivation

## See also

* Rock gardens
* Lichen
* Adventist Youth Honors Answer Book/Nature/Lichens, Liverworts & Mosses
# Horticulture/Mowing for Weed Control

Many weeds can be controlled effectively by simply mowing or cutting them down. This can be done with a mower, brusher, string-trimmer, or scythe.
Weeds that are susceptible to this method includes all trees and shrubs, most vines, and large herbaceous plants. Lawn weeds are of course not controllable by this method, since they are adapted to regular mowing.
Depending on the plant in question mowing can either be done regularly to continually weaken the plant, or in the case of annual weeds simply cut down before seed production to prevent their return the following year.
Disposal of the clippings can generally be done by composting, although care should be taken if seeds are present.
This page is a stub entry in Horticulture. Please see the Manual of Style for guidelines on how to expand it.
# History of Western Theatre: 17th Century to Now/21st American

Plays in American drama that have so far drawn some attention since the beginning of the 21st century include "I Am my own wife" (2003) by Doug Wright (1962-?) and "Doubt: a parable" (2004) by John Patrick Shanley (1950-?).
# History of Western Theatre: 17th Century to Now
## Table of Contents

* Introduction

### 17th century English

* Jacobean
* Caroline
* Restoration

### 17th century French

* Baroque
* Classical

### 17th century Spanish

* Spanish Renaissance
* Late 17th Spanish

### 18th century English

* Early English 18th
* Late English 18th

### 18th century French

* Early French 18th
* Late French 18th

### 18th century Spanish

* Early Spanish 18th
* Late Spanish 18th

### 18th century Italian

* Early Italian 18th
* Late Italian 18th

### 18th century German

* Early German 18th
* Late German 18th

### 18th century Scandinavian

* Early Scandinavian 18th
* Late Scandinavian 18th

### 19th century English

* English Romantic
* English Realist

### 19th century French

* French Romantic
* French Realist
* Boulevard of the 19th

### 19th century Spanish

* Spanish Romantic
* Spanish Realist

### 19th century Italian

* Italian Romantic
* Italian Realist

### 19th century German

* German Romantic
* German Realist

### 19th century Russian

* Russian Romantic
* Russian Realist

### 19th century Scandinavian

* Scandinavian Romantic
* Scandinavian Realist

### 19th century American

* American Romantic
* American Realist

### 20th century English

* English Pre-WWII or Edwardian
* English Post-WWII

### 20th century French

* French Pre-WWII
* French Post-WWII
* Boulevard of the 20th

### 20th century Spanish

* Spanish Pre-WWII
* Spanish Post-WWII

### 20th century Latin American

* Latin American Pre-WWII
* Latin American Post-WWII

### 20th century Italian

* Italian Pre-WWII
* Italian Post-WWII

### 20th century German

* German Pre-WWII
* German Post-WWII

### 20th century Russian

* Russian Pre-WWII
* Russian Post-WWII

### 20th century Scandinavian

* Scandinavian Pre-WWII
* Scandinavian Post-WWII

### 20th century East European

* East European Pre-WWII
* East European Post-WWII

### 20th century American

* American Pre-WWII
* American Post-WWII

### 20th century Canadian

* Canadian Pre-WWII
* Canadian Post-WWII

### 21st century English

* Early English 21st
* Late English 21st

### 21st century French

* Early French 21st
* Late French 21st

### 21st century Spanish

* Early Spanish 21st
* Late Spanish 21st

### 21st century Latin American

* Early Latin American 21st
* Late Latin American 21st

### 21st century Italian

* Early Italian 21st
* Late Italian 21st

### 21st century German

* Early German 21st
* Late German 21st

### 21st century Russian

* Early Russian 21st
* Late Russian 21st

### 21st century Scandinavian

* Early Scandinavian 21st
* Late Scandinavian 21st

### 21st century East European

* Early East European 21st
* Late East European 21st

### 21st century American

* Early American 21st
* Late American 21st

### 21st century Canadian

* Early Canadian 21st
* Late Canadian 21st

## Added material

* Bibliography
* Complete list of plays in English on the Internet
* Complete list of one-act plays in English on the Internet
* Alphabetical list of playwrights (died 1855-1955)
# History of Western Theatre: 17th Century to Now/American

Plays in American drama that have so far drawn some attention since the beginning of the 21st century include "I Am my own wife" (2003) by Doug Wright (1962-?), "Doubt: a parable" (2004) by John Patrick Shanley (1950-?).
# IGCSE Science/Section 2: Structures and functions in living organisms

* Levels of organisation
* Cell structure
* Biological molecules
* Movement of substances into and out of cells
* Nutrition
* Respiration
* Gas exchange
* Transport
* Excretion
* Coordination and response
# IGCSE Science/Section 2: Structures and functions in living organisms/Biological molecules

Carbon is the building block for life, as there are an infinite number of possible carbon-based molecules.

### Carbohydrates

Carbohydrates are types of organic compounds found in food and are the main energy source for humans. For example, sugars (glucose, fructose, sucrose, lactose), glycogen, cellulose or starch.
Simple sugars, called monosaccharides, such as glucose are the building blocks for longer carbohydrates. Starch and glycogen are large molecules (disaccharides or polysaccharides) made from these smaller, simpler units. At the atomic level, all carbohydrates are made out of carbon, hydrogen and oxygen.
To test for glucose:
* Heat a sample with Benedict's reagent
* If it turns from orange to blue, glucose is present
To test for starch:
* Apply iodine to the sample
* If it turns from orange to blue/black, starch is present

### Proteins

Proteins are large, very complex molecules. Whole proteins are made from blocks called amino acids. Amino acids are small, so can be absorbed by the intestine. They are made from carbon, hydrogen, oxygen, sulphur, phosphorus and nitrogen.
Foods rich in protein include nuts, meats and milk.

### Lipids (fats and oils)

Fats and oils are types of lipids. Lipids are made from fatty acids and glycerol. These are made out of carbon, hydrogen and oxygen, like carbohydrates.

### Enzymes

Enzymes are biological catalysts. That means they increase the rate of a chemical reaction by lowering the activation energy, providing an alternate pathway for the reaction to take place, and while they do this they are not used up.
Enzymes have an active site, which is where substrate molecules (the reactants) bind and undergo a chemical reaction. The lock-and-key mechanism is an explanation for how enzymes function:
* Substrate binds active site of enzyme
* Reaction takes place
* Products formed
* Products ejected from the active site
Enzymes can be affected by temperature and pH.
The higher the temperature, the faster the rate of reaction. However at too high temperatures, enzymes denature. This happens as the active site's shape is changed, so substrate molecules can no longer bind to it. The point at which the rate is fastest is called the optimal temperature. Most enzymes in the human body have an optimal temperature of 37.5°C.
At pH values which are too extreme, enzymes denature. This happens as the active site's shape is changed, so substrate molecules can no longer bind to it. The point at which the rate is fastest is called the optimal pH. Most enzymes in the human body have an optimal pH of 7 (neutral).
This is why maintaining a constant body temperature and pH is very important (homeostasis).
# IGCSE Science/Section 2: Structures and functions in living organisms/Levels of organisation

Individual cells are made out of even smaller parts called organelles. Multicellular organisms have tissues: groups of similar cells. Tissues make up organs, which are groups of different types of tissues adapted for a particular function. Organs working together can perform a specific process, they are called organ systems.
An example in the heart: Nucleus (organelle) > Muscle cell > Cardiac (heart) muscle tissue > Heart > Circulatory system > Human
So generally the order is: Organelle > Cell > Tissue > Organ > Organ system > Whole organism
# IGCSE Science/Section 1: The nature and variety of living organisms

* Characteristics of living organisms
* Variety of living organisms
# IGCSE Science/Section 2: Structures and functions in living organisms/Cell structure

Cell organelles: Small structure having definite shape and performing specific functions
They are embedded in the cytoplasm, These structures are called cell organelles. Most cells have these organelles:
| Name | Function |
| Nucleus | It regulates all important activities of the cell and plays an important part during cell division. |
| Cytoplasm | a place for chemical reactions to happen, and it contains enzymes which speed up these reactions |
| Cell membrane | It allows only certain substances to pass through small pores on it and protects the inner cell contents. |
| Mitochondria | It perform cellular respiration, referred as powerhouse of the cell. |
Plants cells have:
| Name | Function |
| Cellulose cell wall | It gives a definite shapes to the cell , allows all substances to pass through it and protect the inner cell contents called protoplasm. |
| Plastids | They are of 3 types: i)Chloroplast- It can trap solar energy and covert it into chemical energy in the form of food through the process of photosynthesis. ii)Chromoplast-It contains coloured(red, yellow, orange)pigments that impart colour to flowers and fruits. iii)Leucoplast-It is colourless pigment that store food in the form of starch, proteins and fats. |
| Vacuole | It stores sugar ,mineral and water in the form of cell sap and maintain the shape of cell. |
Yeast cells have:
| Name | Function |
| Chitin cell wall | to keep the structure of the cell |
| Vacuole | to store nutrients and food |
Animal cells only have the basic organelles, but plants have all the basic organelles and some more: a cell wall, chloroplasts and a vacuole:
# IGCSE Science/Section 4: Ecology and the environment

* The organism in the environment
* Feeding relationships
* Cycles within ecosystems
* Human influences on the environment
# IGCSE Science/Section 5: Use of biological resources

* Food production
* Selective breeding
* Genetic modification (genetic engineering)
* Cloning
# IGCSE Science

Welcome to IGCSE Science!
This should eventually cover Edexcel's (and maybe more exam boards) IGCSE course to higher-tier for Physics, Biology and Chemistry.
This is under construction so for the meanwhile you might want to check out GCSE Science. All the progress made so far is only on Biology, and it's very brief, more like a revision guide/notes than a textbook.

## Contents
### Biology
#### Edexcel

* Section 1: The nature and variety of living organisms
** Characteristics of living organisms
** Variety of living organisms
* Section 2: Structures and functions in living organisms
** Levels of organisation
** Cell structure
** Biological molecules
** Movement of substances into and out of cells
** Nutrition
** Respiration
** Gas exchange
** Transport
** Excretion
** Coordination and response
* Section 3: Reproduction and inheritance
** Reproduction
** Inheritance
* Section 4: Ecology and the environment
** The organism in the environment
** Feeding relationships
** Cycles within ecosystems
** Human influences on the environment
* Section 5: Use of biological resources
** Food production
** Selective breeding
** Genetic modification (genetic engineering)
** Cloning
# IGCSE Science/Section 1: The nature and variety of living organisms/Characteristics of living organisms

An organism is an individual animal, plant or other living thing. All organisms share some characteristics:
* they move
* they respire
* they respond to their surroundings
* they control their internal conditions
* they grow and develop
* they reproduce
* they excrete their waste
* they require nutrition
You can remember these by using the mneomic MRS C GREN:
* Move
* Respire
* Sense
* Grow
* Rreproduce
* Excrete
* Nutrition
# History of the National Hockey League/1942–1967/Breaking the colour barrier

On January 18, 1958, Willie O'Ree joined the Bruins as an injury call-up for a game in Montreal. In doing so he became the first black player in the NHL. O'Ree played only two games with the Bruins in the 1957–58 season. He returned to the NHL in 1960–61, playing another 43 games with Boston. Although he only played 45 NHL games, scoring four goals, it was enough for him to be labeled the "Jackie Robinson of hockey".
O'Ree faced blatant racism from opponents throughout the season, remarking that "people just wanted a piece of me, maybe because they thought I was different, so I had to defend myself. I wasn't going to be run out of any rink." He faced racial slurs from fans when he played in Chicago, Detroit and New York, though the taunts were mostly absent in Montreal and Toronto. O'Ree was supported by his teammates and the fans in Boston. He stated that "they were mean to me in places like Detroit and New York, too. But never in Boston. I'll never forget how my teammates there—men like Johnny Bucyk, Doug Mohns, Charlie Burns and Don McKenney—took care of me. They accepted me totally. All of them had class." O'Ree was traded to Montreal in 1961 but was unable to crack the Canadiens' line-up. He played over 20 minor league seasons, twice winning the Western Hockey League's scoring title, with the Los Angeles Blades in 1964 and the San Diego Gulls in 1969.
O'Ree's breakthrough came several years after another black player, Herb Carnegie was denied the same opportunity. Playing junior hockey with the Ontario Hockey Association's Toronto Rangers in 1938–39, Carnegie was pulled aside by his coach during a practice: "See that man sitting in the blues? That's Conn Smythe, owner of the Toronto Maple Leafs. He says he'd take you tomorrow if he could turn you white." Stung by the comments, Carnegie resolved to excel at the game. He was offered a tryout with the Rangers in 1950, and a spot on their lowest minor league team. "They told me that if I signed with the Rangers and went to New Haven, I would make international headlines. I told them my family couldn't eat headlines. That was probably when the Rangers decided to forget about me."
# History of the National Hockey League/1942–1967/Dynasties
## Dynasties

* Toronto Maple Leafs
* Detroit Red Wings
* Montreal Canadiens
# History of the National Hockey League/1942–1967/Dynasties/Toronto Maple Leafs/1967 Stanley Cup Finals

‹ Contents ‹ Toronto Maple Leafs
The Original Six era ended with the 1967 Stanley Cup Finals between the two-time defending champion Montreal Canadiens, and the Maple Leafs. The oldest team in the league, the third-place Leafs were led in goal by 37-year-old Terry Sawchuk and 42-year-old Johnny Bower. Known as the "over the hill gang", Toronto became the oldest team to win the Cup by defeating the favoured Canadiens in six games. The Maple Leafs have not appeared in the Stanley Cup finals since, although they came close to a Stanley cup Finals rematch against the Canadiens in 1993, instead losing to the Wayne Gretzky-led Los Angeles Kings in the Clarence Campbell Conference (now Western Conference) Finals.
Montreal Canadiens ›