Unit 1
Explain the difference between biotic and abiotic Factors
Biotic = Living; animals, trees etc
Abotic = Nonliving; water, rock, soil etc
What is primary succession?
The succession where the ecosystem is laid bare to rock; no life
Define a biome and provide two examples of different biomes
A biome is a specific ecosystem with certain animals and climate; answers vary
List the four factors that influence population size.
Birth rate; death rate; immigration; emigration
What are the characteristics of Stage 4 of the DTM?
Stable death and birth rate; stable population growth; USA
Explain why keystone species are important to an ecosystem.
Keystone species affect the health of the ecosystem; removed and ecosystem collapse
What are indicator species?
A species that indicates the health of an ecosystem
Describe how plants in desert biomes have adapted to store water.
Water retention due to waxy leaves; thick stems
Define carrying capacity and explain what happens when a population exceeds it.
Carrying capacity is the limit an ecosystem can maintain a population if exceeded population experiences a die off.
What countries today are examples of Stage 2? Why?
Kenya; high death rate; positive population growth
Why are producers like algae so important in food webs?
They are the basis for all energy in a food web. (minus the sun)
Define ecological succession.
the gradual, sequential change in the species composition of an ecological community over time;
What are the main characteristics of the temperate deciduous forest biome?
Seasons; mild winters; warm summers; deciduous trees
Distinguish between density-dependent factors and density-independent factors.
Density dependent = has to have population; disease
Density Independent = does not need population; natural disasters
What does an upside down triangle population pyramid tell us about the country's population growth?
The country is in a negative population growth; Japan
What percentage of energy is typically passed from one trophic level to the next?
10%
What is secondary succession?
Ecosystem is laid to bare soil
Describe what the climatograph shows us about that biome.
Climatograph shows us the average temperature and rainfall of a biome.
Which survivorship type is humans?
Type 1 = live long and prosper
What is the Demographic Transition Model (DTM)?
A model that shows the stages that a country goes through as it population tries to grow and fluctuates.
Why are ecosystems with greater species variety more resilient?
More genetic diversity; Greater resistance to disease
Why would an area recover faster through secondary succession than through primary succession?
The soil is already built, so plants have a basis to start to grow. There is no soil in primary succession.
How does rainfall influence the type of biome that develops in a region?
More rainfall = more plants = more animals
Describe exponential and logistic growth. Sketch a graph.
Exponential = fast and quick; unlimited resources
Logistic = natural up and down; limited resources/carrying capacity
What are some negative implications of rapid population growth?
Water and food shortage; resource scarcity