Unit 3 Exam Study Guide Flashcards
What is biodiversity?
It refers to the diversity of species on Earth.
What is a species?
A species is a type of organism. Often described as individuals that can reproduce (exchange genetic information) and produce fertile offspring.
_________ of the same _______ look alike because they share a genetic history, but there is a _________.
Individuals, species, variation
Members of different _______ can occasionally ________ and produce ______.
species, interbreed, hybrids
Species can be grouped into larger groups called _____.
taxa
Overall most groups of species are _______ but some more than others.
declining
What are five ways humans are threatening other species?
- Habitat loss (reduction in quality of habitat where species live)
- Invasive species (species not native to an environment can compete with native species for resources)
- Pollution
- Overharvesting (unsustainable hunting, poaching, or harvesting)
- Climate change
Human activities are having an impact on ________.
biodiversity
What is species diversity?
One way to measure species diversity is to count the number of species in an area. This is called species diversity.
What is species richness?
Species diversity is the variety of different species in a particulate place.
Scientists estimate that there are between _________ and ________ species on Earth.
5.3 million, 1 trillion
Only about _______ species have been named.
2 million
__________ varies in different parts of the world
Biodiversity
What are hotspots?
Hotspots are the most biologically diverse and threatened areas on Earth.
Who manages hotspots?
Because hotspots are important for conservation, many are managed/sustained by indigenous communities.
Hotspots cover ___ of Earth’s surface but have over ___ of species.
<1.5%, 30%
_________ are biodiversity hotspots.
Tropical rainforests
Every degree of warming will increase the impacts of ________ on other species.
climate change
What are endemic species?
Endemic species are species that are found in only one area on Earth. Ex. Golden toad
Why are endemic species prone to extinction?
If they disappear from their one area, they will go extinct because they don’t exist anywhere else. (Typically smaller populations).
What are specialist species?
Specialist species make their living in a particular way. Ex. Giant panda, Green sea turtle, Yucca
Why are specialist species prone to extinction?
They can only eat one food or live at a certain temperature or reproduce in a particular place. They don’t adapt easily to changes in the environment.
What are generalist species?
Generalist species tolerate a large range of environmental conditions. Ex. House sparrow, Raccoon
Why are generalist species less prone to extinction?
They thrive around humans: they eat almost everything and adapt to changes in environment.