UNIT 9 POPULATION AND ECONOMY
POPULATION
Population: number of people who live in an area. There are two types of population:

• urban population: people who live in towns and cities (city: more than 10.000 inhabitants).

• rural population: people who live in villages. (village: less than 10.000 inhabitants).

Inhabitant: person who lives or occupies a place.

Census: official counting of a country´s population.

Population density: number of inhabitants in a place compared with the size of the place.

Watch this video about population density it´s very interesting and talks about the same concepts we study in class.

Warning!: she speaks very quickly so use the pause bottom to understand.

MIGRATION

Migration is the movement of people from one place (village, city, country) to another.

• Emigration: when you leave your village, city or country to live in another one.
• Inmigration: when someone come to our village, city or country to live in.

This is a world map showing the global net migration pattern. It gives us an idea of the countries that receive more inmigrants. For more information click on the picture.

And here, two maps about migration flow in the world. Maybe they are a bit difficult but be patient and try to understand the arrows.

UNIT 4  ECOSYSTEMS

An ecosystem is a group of plants, animals, and other living things that live in the same surroundings. It also includes nonliving materials, for example, water, rocks, soil, and sand. It consists of a biological community and its physical environment. All of Earth's ecosystems together constitute the biosphere.

• Terrestrial ecosystems include forest, savanna, grassland, scrubland, tundra, and desert.
• Marine and freshwater aquatic ecosystems include oceans, lakes, rivers, and wetlands.

COMPONENTS

• living things: species, population, community
• habitat
• interrelationships

A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
A population is a group of the same species of organism living in one area at the same time.
A community is a group of animals and plants that live together in the same environment.
A habitat is the place where an organism or a community of organisms lives. It includes all living and nonliving factors or conditions of the surrounding environment.

More information about this picture in:

 

Read about these pictures in:

Mastering Sixth Grade Science with Mrs. Phillips

RELATIONSHIPS

• competition
• mutualism
• parasitism

The struggle between two or more individuals or species for a common resource is called competition.
An interaction between two species that benefits both of them is called a mutualism.
In parasitism one member of the relationship benefits while the other is harmed.

Games and videos in this website: