Notes, summaries, assignments, exams, and problems for Secondary education

Chemical Evolution and Biological Evolution: The Miller-Urey Experiment and Endosymbiotic Theory

Biology6.76 KB


CHEMICAL EVOLUTION

Chemical evolution refers to the processes that created the molecules that make up living things (biomolecules) and then formed structures called protocells, which exhibited a certain organization and were separated from the environment by membranes.

THE MILLER-UREY EXPERIMENT

  1. They introduced the gases Oparin believed existed in the primitive atmosphere into a chamber.

  2. Then they ran electric currents through it to simulate the energy from lightning.

  3. The products created by the chemical reactions that took place in the chamber collected in a container that imitated the 'primitive ocean'.

  4. When they extracted the liquid of the 'primitive ocean' and analyzed it, they observed biomolecules that had formed from the simple inorganic products.

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The Crisis of the Spanish Monarchy (1917-1931)

History2.9 KB

The Crisis of the Canovas System (1917-1923)

In 1917, Spain suffered a crisis that deeply affected three areas:

  • Military: The army demanded that wages be increased and that army rank be determined by seniority, not by merit in battle.
  • Politics: An assembly of Catalan parliamentarians demanded decentralization.
  • Society: Left-wing political parties and trade unions carried out a general strike on August 13th to protest the rise in prices and overthrow the government.

When the crisis was finally over, the period from 1919-1923 saw Spain experience political decline and form unity governments made up of members from all the different parties. These governments didn't last long.

Domestic and International Issues

Domestically, social unrest increased in...

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Characteristics of Fungi, Protozoa, Algae, and Monera Kingdoms

Biology2.08 KB

FUNGI KINGDOM

Cellular Organization:

Unicellular or multicellular, the cells are eukaryotic, they have no tissues.

Size and Shape:

Unicellular fungi, like yeast, are round or oval and microscopic in size.

Nutrition:

Heterotrophic, many are saprophytes, feeding on organic material from animals or plants.

Lifestyle:

They can be free-living symbionts or parasites.

Reproduction:

Unicellular asexual, multicellular asexual, or sexual.

PROTOCTIST KINGDOM PROTOZOA

Cellular Organization:

Unicellular, they have no tissues.

Size and Shape:

Oval, round, oblong, half-moon. All are microscopic.

Nutrition:

Heterotrophic, feeding on bacteria and algae.

Habitat and Lifestyle:

Most are free-living.

Reproduction:

They reproduce asexually by binary fission.

Movement:

They move by using...

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Hotel Classification, Grading, and Organization: A Comprehensive Guide

English4 KB

Hotel Classification and Grading

Hotel Origin: The word "hotel" comes from the Latin "hospitale cubiculum," which referred to guest rooms in Roman homes. Later, monks provided shelter to travelers in houses called "hospitals." Upper-class travelers stayed in luxurious accommodations with private rooms and services called "hotels." Today, hotels offer paid lodging for short stays, various amenities, and conference rooms for meetings and events. Hotels can operate year-round or seasonally and are found worldwide.

Star Rating and Grading

Hotels are graded and classified based on minimum standards of facilities and services. The most common system is the "star" rating:

  • One star: Basic facilities
  • Five stars: Extensive facilities
  • Six and seven stars: Luxury
...
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Simple Machines: A Comprehensive Guide to Mechanical Advantage

Physics3.31 KB

Simple Machines and Mechanical Advantage

Simple machines are devices that make work easier. They do this by changing the magnitude or direction of a force. Many simple machines are combined to create complex machines.

Wheel and Axle

A wheel is attached to a central axle so that when one turns, the other must turn. A longer motion at the wheel's edge is converted to a shorter, more powerful motion at the axle. Conversely, a short, powerful force at the axle moves the wheel's edge a greater distance.

Pulley System

A single pulley simply reverses the direction of a force. When two or more pulleys are connected together, they permit a heavy load to be lifted with less force. The trade-off is that the rope's end must move a greater distance than the...

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The Impact of Tourism on the Environment and Economy

Geography2.54 KB

Tourism

The tourism industry

Tourism is the temporary movement of people from their place of residence to another place in order to enjoy their free time. Tourism is therefore related to leisure. The development of the tourism industry involves creating the necessary transport and hospitality infrastructure to meet demand: airports, roads, accommodation, restaurants, etc. The main characteristic of the tourism industry is seasonal variation or seasonality.

Repercussions of tourism

It represents a significant source of revenue for a country. It creates jobs, but many of them are temporary, due to seasonality. It improves cultural relations between citizens of different countries. Destroys natural landscapes. In developing countries, the destination...

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Axis Powers, German-Soviet Pact, Blitzkrieg, and WWII Key Events

History3.18 KB

Axis Powers

Axis powers: It was an alliance led by Nazi Germany, Fascist Italy, and Japan. They all had dictatorial regimes.

German-Soviet Pact

German-Soviet Pact: The German-Soviet Pact or Ribbentrop-Molotov Pact was a non-aggression agreement signed by Nazi Germany and the Soviet Union one week before the WWII. It included a secret clause to invade Poland at the same time and to distribute Eastern Europe.

Blitzkrieg

Blitzkrieg: The blitzkrieg was a new war tactic developed by Germany before the WWII and used since its beginning. It was based on the use of planes, the fast advance of tanks, and the occupation of the land by soldiers later. The troop advance was extremely fast and thanks to it, Germany occupied most of Europe between 1939-1941.

Battle

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Oak Processionary Moth (OPM): Risks & Control in the UK

Geography2.32 KB

Oak Processionary Moth (OPM) in the UK

Threats to Oak Trees and Public Health

The oak processionary moth (OPM) is an invasive pest that poses significant threats to oak trees and human and animal health. Accidentally introduced to England in 2005, OPM larvae (caterpillars) feed on oak leaves, potentially defoliating entire trees and making them susceptible to other diseases and stressors.

Government Control Measures and Protected Zones

The UK government has implemented a comprehensive program to monitor, control, and minimize the spread of OPM. Most of Greater London and some surrounding counties are established OPM areas. To prevent further incursions, the rest of the UK is designated as a Protected Zone (PZ) under European Union regulations,

...

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Small Business Advantages and Growth Methods

Economics3.06 KB

Small Business Advantages:

  • Greater focus: focus where they want; in places with greater profitability; in specific markets
  • Greater cachet: greater sense of exclusiveness so they can charge more for their output, leading to higher profit margins
  • Greater motivation: more prestige can motivate managers/employees
  • Competitive advantage: giving a more personalized service and being more flexible
  • Less competition: focusing on a niche gives limited competition
  • Internal growth: slowly, steady and out of the existent operations of the business. They don't take many risks. Expands by selling more products or by increasing its product range. Usually self-financed
  • External growth: quick and riskier methods. Expands by entering into an arrangement with another
...
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Fertility, Mortality, Demography, and Population: Key Concepts Explained

Geography1.1 KB

Fertility

The number of live births per 1000 women aged between 15-49.

Mortality

The mortality in a particular place or situation is the number of people who die.

Demography

The study of population statistics.

Life Expectancy

The average period that a person is expected to live.

Density

A measure of the amount of information on a storage medium.

Migration

Seasonal movement of people from one region to another.

Population

All the inhabitants of a particular place.

One Child Policy

An official program initiated in the late 1970s and early '80s by the central government of China, the purpose of which was to limit the great majority of family units in the country to one child each. The rationale for implementing the policy was to reduce the growth rate of China'...

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