4.4.2 Ecology Flashcards
What is an ecosystem?
All the living and non-living components in an environment
Give an example of a natural ecosystem.
Grassland, desert, forest, stream, tundra, pond, coral reef
What is a population?
Total number of one species in an ecosystem
What type of organism are producers?
Plants and algae
Explain why all food chains begin with a producer.
They make their own food using energy from the Sun
What does it mean if an organism is a tertiary consumer?
It eats secondary consumers
Construct the food chain:
Leaf -> caterpillar -> bird -> cat
Which word refers to an animal that kills and eats other animals?
Predator
Why are organisms in the same habitat in competition?
Because there are limited resources
Identify three resources dandelions may compete for.
Space, mineral ions, water, light
Identify three resources badgers may compete for.
Territory, food, water, mates
What is interspecific competition?
Competition between members of different species
Give an example of interspecific competition.
Zebra and wildebeest competing for grass. Lions and hyenas competing for prey on the African savannah
What is intraspecific competition?
Competition between members of the same species
What is interdependence?
How species within a community depend on each other
What is the term for a community where the population sizes remain constant?
Stable community
What is an abiotic factor?
A non-living factor in an ecosystem
What is a biotic factor?
A living factor in an ecosystem
Is the mineral content of soil a biotic or abiotic factor?
Abiotic
How would lack of light affect plants?
Reduce photosynthesis so less plants growing or plants grow smaller
How would lack of light affect animals?
Reduce photosynthesis so less plants growing or plants grow smaller so less food available for animals to eat
What is distribution?
Where organisms are found in a habitat
Name two factors that affect the distribution of an organism.
Light, water and nutrient availability.
How can the distribution & abundance of species in an ecosystem be determined?
Sampling
Why is it difficult to sample animals?
Because the are mobile
What is a quadrat?
A square frame of a known size used for sampling
Why must quadrats be placed randomly?
To improve the validity of the study
Described 2 ways that a transect can be used for sampling.
Count the number of organisms that touch the line, or place quadrat at intervals along the line
What is the mean number of organisms if the following are found in 6 quadrats – 1,5,15,20,42,37?
20
What is high biodiversity?
a wide range of different plant and animal species living in an ecosystem
Why is high biodiversity important?
allows a wide variation of food sources to help a species to survive, provide us with food and other products
What effect are humans having on biodiversity?
Reducing it
What are extremophiles?
Organisms that can survive in extreme conditions
How do human actions affect global warming?
Deforestation has increased CO2 in the atmosphere causing global temperatures to rise