Eighth grade geography and biology graduation always review materials and outlines.

1. The earth is an irregular sphere with slightly flat poles, and its average diameter is 6371m.

2. On the globe, the circle around the globe along the east-west direction is called the latitude line. All latitudes are circles, which can be called latitude circle; The length of latitude circle is long and short, with the equator being the longest, gradually shortening towards the poles and finally reaching a point. Weft lines indicate both east and west directions. The equator is the longest latitude, about 4 thousand kilometers long. It is equal to the distance between the poles and divides the earth into two hemispheres: the south and the north. The equator is the zero latitude on the globe. The latitude north of the equator is called north latitude, and it is customary to use "n" as the code; The latitude south of the equator, called south latitude, is customarily represented by "S".

3. On the globe, the line connecting the north and south poles and intersecting the latitude perpendicular is called meridian, also called meridian. All the warps are semicircular; They are all equal in length and indicate the north-south direction. The zero meridian on the globe is called the prime meridian, which is divided into 18 from the prime meridian to the east and west. The 18 in the east belongs to the east longitude, and it is customary to use "E" as the code name, and the 18 in the west belongs to the west longitude, and it is customary to use "W" as the code name. It is customary in the world to use warp coils of 2W and 16E as the boundary between the eastern and western hemispheres.

4. The earth keeps rotating around its axis, which is called earth rotation. The direction of earth rotation is from west to east. It takes about 24 hours to rotate once, which is one day. In this way, the phenomenon of alternating day and night is produced.

5. The revolution of the earth and seasonal changes. While the earth rotates, it also revolves around the sun. The direction of the earth's revolution is naturally from west to east, and the time of revolution is one year. The orbital plane of revolution always keeps an angle of 66.5 with the earth axis. Because of the revolution of the earth, there are seasonal changes.

6. The tropics lie between the Tropic of Cancer, and there is direct sunlight in a year. The ground gets the most sunlight and heat, and the climate is hot all year round. The tropic of cancer is the dividing line between tropical and temperate zones. The cold zone is located in the area north of the Arctic Circle and south of the Antarctic Circle, with extreme nights and days. Polar circle is the dividing line between cold zone and temperate zone. In the temperate zone between the Tropic of Cancer and the Arctic Circle, and between the Tropic of Cancer and the Antarctic Circle, there is no extreme night and day in a year, and the solar light and heat obtained on the ground is less than that in the tropics and more than that in the frigid zone, and the climate changes obviously in four seasons.

7. Scale, legend and notes of the three elements of the map. The smaller the area drawn on the map, the more detailed the content to be represented, and the larger the scale to be selected; On the contrary, the smaller the scale. On the map, it is usually "up north and down south, left west and right east"

8. The vertical distance above sea level of a certain place on the ground is called altitude. The vertical distance from one place to another is called relative height.

9. Contour lines connect points with the same altitude into lines, which is the contour line. Each contour line has a corresponding altitude value. Where the slope is steep, the contour lines are dense; Where the slope is gentle, the contour lines are sparse.

1. The ocean area accounts for 71%, while the land area only accounts for 29%. The mainland and its nearby islands together are called continents. All in the northern hemisphere are Europe and North America. Most people are used to taking the Urals, ural river and the Great Caucasus as the dividing line between Europe and Asia. The Suez Canal is the dividing line between Asia and Africa. The Panama Canal is the dividing line between North America and South America. Antarctica is mainly located in the Antarctic circle, surrounded by oceans.

11. land topography people divide the terrain into five basic types: mountains, plains, plateaus, basins and hills.

The altitude of mountainous areas is relatively high, generally more than 5 meters, with undulating peaks and steep slopes, and some mountainous areas are distributed in strips. Among them, the most prominent are two huge mountain systems composed of several tall mountains: one is the Alps-Himalayan mountain system across the south-central part of the Eurasian continent; The other is the Cordillera mountain system running through North and South America, which consists of Rocky Mountain, Andes Mountain and other mountains.

The elevation of the plain is low, generally below 2m, and the ground is flat or slightly undulating, so "endless" is often used to describe the flatness of the plain. The largest plain in the world is the Amazon Plain in South America.

The terrain in Europe and Africa is relatively simple, with plains and plateaus as the main parts; The topography of Asia is more complex, with high terrain in the middle and low surrounding areas, wide plateaus and mountains, and plains distributed around the mainland.

12. The forces that make the terrain change are called internal forces, such as crustal movement, volcano, earthquake, etc., which are all manifestations of the internal forces of the earth. Volcanoes and earthquakes in the world are mostly distributed in areas with active crustal activity, mainly concentrated in the Pacific Rim and the Mediterranean-Himalayan Mountains. Forces from outside the earth are called external forces, such as running water, wind, waves and glaciers.

13. Weather is the atmospheric condition of a place in a short time, such as sunny, rainy, hot and cold. It's always changing. Climate is the average weather condition in a place for many years, and generally it doesn't change much.

14. During the day, the temperature is sometimes high and sometimes low. The highest temperature on land generally appears after noon (about 14: ); The lowest temperature appears around sunrise. In a year, the monthly average maximum temperature in most parts of the world appears in July in the northern hemisphere and January in the southern hemisphere. The monthly average minimum temperature appears in January in the northern hemisphere and July in the southern hemisphere. The difference between the highest monthly average temperature and the lowest monthly average temperature in a place is called annual range.

15. The world temperature gradually drops from low latitude to polar regions; At the same latitude, the sea and land have different temperatures. In summer, the land temperature is high and the ocean temperature is low. Winter is the opposite. The temperature is also affected by the terrain. As the altitude increases in mountainous areas, the temperature will gradually decrease. About every 1 meters above sea level, the temperature drops by about .6℃.

16. The general law of precipitation distribution in the world: there is more precipitation near the equator; Less precipitation in polar regions; On both sides of the Tropic of Cancer, there is less precipitation on the west coast of the mainland and more on the east coast of the mainland; Mid-latitude coastal areas have more precipitation, while inland areas have less precipitation.

17. Rainy areas throughout the year: there is a lot of monthly precipitation near the equator, such as Singapore; Annual rainless areas: there is little monthly precipitation in inland areas and polar regions, such as Cairo, Egypt; Rainy area in summer: on the east coast of the mainland near 3~~4 north latitude, it is rainy in summer and rainy in winter, such as Beijing, China; Rainy area in winter: on the west coast of the mainland near 3~~4 latitude, it is rainy in winter and rainy in summer, such as Rome, Italy; Perennial humid area: in the west coast of the mainland at 4~~6 north latitude, the area affected by the westerly wind blowing from the ocean all year round is humid every month with moderate rainfall, such as London, England.

18. Main climate types and distribution in the world

1. Main tropical climate types

1. Tropical rain forest climate is mainly distributed near the equator, with high temperature and rainy all year round.

2. The tropical grassland climate is mainly distributed in the north and south sides of the equatorial rainforest climate in Africa and South America. It is hot all year round, and there are obvious dry seasons and rainy seasons in a year.

3. The tropical monsoon climate is most obvious in the Indian Peninsula and Indochina Peninsula in the south and southeast of Asia. This climate is hot all year round, and a year can also be divided into dry and rainy seasons, and the wind direction changes with the seasons. In dry season, the wind blows from land to sea, and there is little rain; In the rainy season, the wind blows from the ocean to the land, and the precipitation is concentrated.

4. The tropical desert climate is mainly distributed in the west coast and inland areas of the mainland near the Tropic of Cancer. This kind of climate has little precipitation, is hot and dry all year round, and there are large deserts on the ground.

2. Main climatic types of temperate zone

1. Temperate and subtropical monsoon climate are distributed in the eastern part of Asia. It is hot and rainy in summer and cold and dry in winter. It is roughly bounded by the isotherm of the average temperature of ℃ in January, with temperate monsoon climate in the north and subtropical monsoon climate in the south.

2. The Mediterranean climate is mainly located in the middle and low latitudes on the west coast of the mainland, with the Mediterranean coast being the most distributed, with hot and dry summers and mild and rainy winters.

3. The temperate continental climate is mainly distributed in mid-latitude inland areas, with hot Leng Xia in winter, great temperature change, less precipitation and concentrated in summer.

4. The temperate maritime climate is located on the west coast of the mid-latitude continent, with the widest distribution in western Europe, mild and rainy, and the annual changes of temperature and precipitation are relatively small.

19. Land, sunshine, water, minerals, forests, etc., which are valuable to human beings, are all natural resources. According to the characteristics of its formation, it can be divided into two categories: one is renewable resources; One is non-renewable resources. Renewable resources refer to resources that can be regenerated or recycled in a short time; Non-renewable resources refer to resources that can't be produced after being used up in human history.

2. Land use types can be divided into cultivated land, woodland, grassland, building land and other types.

21. The humid plain in temperate zone has flat terrain and warm climate, which is suitable for developing agriculture and is the main distribution area of cultivated land in the world. Large areas of coniferous forests and rainforests are preserved in the sub-cold zone with cold and wet climate and the hot and rainy tropical zone. The grassland area in tropical and temperate semi-arid areas is vast, which is the main distribution area of animal husbandry in the world.

22. There are three main forms of water on the earth: ocean water, land water and atmospheric water. There are many forms of terrestrial water, such as glacier water, groundwater, lake water, swamp water, river water and biological water. There is a lot of water on the earth, but more than 96% is ocean water. Among the fresh water resources, glaciers store the most water, and now people use a lot of fresh water resources, mainly river water, lake water (freshwater lake water) and part of groundwater. The main ways to protect water resources are: saving and rational use of water and reducing the waste of water resources; Preventing and controlling water pollution; Afforestation to prevent soil erosion; Desalinate seawater and expand fresh water sources.

23. The forest in the main dispatching room of nature has the functions of regulating atmospheric composition, purifying air, containing water, increasing air humidity, preventing wind and protecting fields, and preserving water and soil. Therefore, people call the forest "the general adjustment room of nature". There are 4 billion hectares of forests in the world, mainly coniferous forests and broad-leaved forests. Most of the global forest resources are distributed in the northern hemisphere.

24. The population growth rate is different in the world, especially in different continents. Africa is the fastest growing continent in the world, followed by South America, and Europe is the slowest. 2% in Europe; 15% in Asia; 1% in North America; South America is 17%; Oceania is 14%; Africa is 27%.

25. After the Second World War, the scale of population migration became smaller, and population migration mainly took three forms. The first type is scientific and technological migration, that is, a large number of high-quality talents move from developing countries to developed countries. The second is the export of labor force. The basic direction of foreign labor flow is from developing countries to developed countries, from poor countries to rich oil exporting countries, and from densely populated families to sparsely populated countries. The third is international refugee migration.

26. Eastern and southern Asia, Europe and eastern North America are the most densely populated areas, and the densely populated areas are mainly located in the plains near the middle and low latitudes. In the cold tundra zone, the ice sheet belt, the vast cold zone coniferous forest belt, the undeveloped tropical rain forest belt, the arid desert area, as well as the high-lying plateau, mountainous area and sparsely populated.

27. The proportion of a country's urban population in the total population is often one of the criteria for measuring a country's development level. More than 7% of the population in developed countries in the world is urban population, while the urban population in developing countries accounts for just over 3% of the population. Nowadays, the phenomenon of large-scale migration of rural population to cities mainly occurs in developing countries.

28. Caucasians generally have light skin color, eyes and hair color, wavy hair, high nose, thin lips and more body hair. They are mainly distributed in Europe, North America and Oceania. Yellow people have light yellow or brownish black skin, straight black hair, flat face and medium body hair. They are mainly distributed in eastern Asia. Black people have dark skin, curly hair, thick lips and less body hair. They are mainly distributed in Africa, Oceania and the United States.

29. There are more than 19 countries in the world, and the areas of famous countries are different. Russia, with the largest area, has more than 17 million square kilometers. China occupies the third place with an area of about 9.6 million square kilometers. The smallest is the Vatican.

3. The land, territorial sea, territorial waters and airspace within the national boundaries are collectively referred to as territory.

living things

1. The same characteristics of living things: 1. Living things need nutrition; 2. Living things can breathe; 3. Living things can excrete wastes produced in the body; 4. Living things can respond to external stimuli; 5. Living things can grow and reproduce; 6. Except viruses, living things are all made up of cells

2. Classification of living things: (1) According to morphological and structural characteristics. Other organisms (2) divide organisms into terrestrial organisms according to their living environment, and aquatic organisms (3) divide organisms into crops, poultry, domestic animals and pets according to their uses

3. Biosphere: The place on the earth suitable for living organisms is actually just a thin layer on its surface, which is called biosphere, and the thickness is about 2 kilometers, including the bottom of the atmosphere, most of the hydrosphere and the surface of the lithosphere.

4. Basic conditions provided by the biosphere for the survival of living things: All living things such as animals and plants need the same basic conditions, they all need nutrients, sunlight, air and water, as well as suitable temperature and a certain living space

5. Environmental factors affecting living things:

(1) Abiotic factors affect living things: the life of living things will be affected by abiotic factors. When one or several factors in the environment change dramatically, it will affect the life of organisms and even lead to their death. Mainly light, temperature, water, air and so on.

(2) the influence of biological factors on organisms: predation, competition and cooperation

6. Ecosystem: In a certain region, the unified whole formed by organisms and the environment is called ecosystem. There are producers (plants), consumers (animals), decomposers (microorganisms)

7. Food chain and food web:

(1) The relationship between producers and consumers is mainly the relationship between eating and being eaten, thus forming a food chain.

(2) In an ecosystem, there are often many food chains, which are interlaced with each other to form a food web.

(3) The matter and energy in the ecosystem flow along the food chain and food web. The energy entering the ecosystem is the solar energy fixed by plants through photosynthesis, which means that energy is stored in plants in the form of organic matter, and energy is gradually consumed by many organisms during the flow of the food chain. That is, energy gradually decreases in the energy flow and cannot be circulated. The material flow is also gradually decreasing, but it can be circulated.

(4) The biological system has certain self-adjusting ability. In the ecosystem, toxic substances will accumulate through the food chain. However, this regulation ability of the ecosystem is limited, and when it exceeds this limit, the ecosystem will face collapse.

8, health