ABIOTIC FACTORS
Which of the following pairs would be classified as abiotic factors?
a) Sunlight and plants
b) Air temperature and bushfires
c) Nutrients in soil and worms
d) Rainfall levels and number of fish
b) Air temperature and bushfires
Which of the following pairs would be classified as biotic factors?
a) Water temperature and plants
b) Koalas and bushfires
c) Predators and parasites
d) Humidity and oxygen levels
c) Predators and parasites
Names 2 sampling techniques we have learnt about
Quadrats and capture-recapture
What does “population size” mean?
The number of individuals of a species in a specific area.
What effect can overfishing have on population size in marine ecosystems?
reduces fish population sizes
Name two abiotic factors that could affect plant growth in an ecosystem.
Light intensity and water availability (also acceptable: temperature, soil nutrients, pH).
Name 3 examples of biotic relationships
Any of these; mutualism, commensalism, parasitism, predator/prey, competitors
A square frame placed on the ground to count organisms in a small area is called a _______
Quadrat
What does “species diversity” refer to?
The number of different species in an area and how evenly they are distributed.
What does habitat loss do to biodiversity?
Reduces it
Name 3 natural disasters
Drought
Bushfires
Flood
Cyclones/hurricanes
Volcanoes/earthquakes
What type of relationship is this?
Clownfish and sea anemones — the clownfish gets protection from predators among the anemone’s stinging tentacles, and the anemone gets cleaned and gains nutrients from the fish’s waste.
MUTUALISM
This sampling method is best suited for estimating populations of plants or slow-moving organisms.
Quadrat sampling
Which ecosystem would likely have higher species diversity: a rainforest or a desert? Explain why.
Rainforest, because it has more resources (water, food, stable climate) supporting more species.
List 3 ways human activity can reduce species diversity.
EG; Habitat destruction, pollution, and deforestation can remove or kill species, invasive species.
Explain how light intensity can affect the distribution of plants in an area.
Plants need light for photosynthesis, so areas with higher light intensity support more plant growth.
Some plants are adapted to low light, so they grow better in shaded areas, affecting where different plants are found.
What type of relationship is this?
Cattle egrets and cattle — egrets follow cattle and eat insects stirred up by their movement, while the cattle are not helped or harmed.
COMMENSALISM
Scientists capture 40 frogs in a pond, mark them, and release them. A week later, they capture 50 frogs, and 10 are marked. This method is used to estimate the total frog population. What is the name of this method?
Capture-recapture
What does it mean if a species has a “large population size”?
There are many individuals of that species in the area.
Why does habitat destruction usually lead to a decrease in species diversity?
Because many species lose their homes and food sources, causing some to die out or move away.
Describe how temperature can influence the activity of animals in an ecosystem.
In colder temperatures, many animals are less active or may hibernate, while in warmer temperatures, activity levels generally increase.
Two plant species growing in the same area; list 3 things they may compete for.
sunlight, water, and nutrients
Why do scientists use sampling techniques to estimate population sizes?
Examples;
If one species dominates an area and few others are present, is species diversity high or low?
LOW SPECIES DIVERSITY
Why can introducing a new species (invasive species) reduce native species populations?
Invasive species compete for resources or prey on native species, causing their populations to decline.