life science Flashcards
What is biodiversity?
Biodiversity is the variety of life in Earth’s land, freshwater, and marine
ecosystems. (The different organisms)
What is the difference between high and low biodiversity?
High diversity is when there are many different species and many individuals of
those species while low biodiversity is when there is a low number of species in
an ecosystem
Why do humans use natural resources?
To survive and thrive
How do humans negatively impact the environment?
Directly by overharvesting of plants and animals and indirectly by construction,
mining, and taking away animal habitats
How do humans positively impact the environment?
Recycle, compost, use a reusable water bottle and reusable bags
If the population increases, how does that affect the amount of fossil fuels?
As the number of humans increases, the use of fossil fuels increases which
causes the availability of fossil fuels to decrease
How does fossil fuel use impact the atmosphere?
The use of fossil fuels releases pollution into the environment
What is direct observation?
Directly counting individual organisms
What is direct observation?
Directly counting individual organisms
What is indirect observation?
Observing the signs of the organism
What is sampling?
Estimate the number of organisms by counting the number in a small area then
multiply to find the number in a larger area
What is mark-and-recapture?
Estimate the number of organisms by capturing organisms. Count the number,
mark them and release. Capture again- this time count total number, plus count
how many are marked. Use a mathematical formula to calculate total population.
(Formula is question 27.)
How can populations change in size?
Populations can increase or decrease
What is the major way in which new individuals are added to a population?
birth
What is birth rate?
Birth rate- the number of births in a population in a given time
What is death rate?
Death rate- the number of deaths in a population in a given time
What is the major way organisms leave a population?
Death
What is immigration?
Immigration- organisms moving into a population
What is emigration?
Emigration- organisms leaving a population
What is population density?
Population density is the number of individuals in an area of a specific size
What is carrying capacity?
the largest population that an area can support
What is a limiting factor?
An environmental factor that causes a population to decrease or stop growing
how is water a limiting factor?
cells and tissues are made of water, so all living things need water to survive
how are predators limiting factors?
feed on abundant prey, so the amount of prey determines the amount of predators
how is light a limiting factor?
plants and other organisms that make their own food need light for photosynthesis
how is disease and parasites a limiting factor?
they will spread more quickly in densely populated areas
(more crowded)
how are weather conditions a limiting factor?
Changes in weather conditions such as temperature and the
amount of rainfall as well as events such as floods & hurricanes
how is food a limiting factor?
all organisms (except plants) obtain food by eating plants and other
organisms
how living space a limiting factor?
organisms need enough space to live, obtain resources, etc
What is random sampling?
Estimate the number of organisms by counting the number in a small area then
multiply to find the number in a larger area
What is the formula for population density?
Population density = Number of individuals ➗Unit Area
What is the formula for population when using the mark-and-recapture method?
(total number captured) x (number marked) ➗ Total number captured with marks
