Biodiversity Basics
What does the term biodiversity mean?
The variety of life on Earth, including species, ecosystems, and genetic diversity.
What is the definition of a species?
A group of organisms that can reproduce successfully (offspring can also reproduce).
What do food chains show us?
The flow of energy between organisms in a linear path.
Define adaptation.
A variation that improves survival in a specific environment.
What does the Diversity Index (D.I.) measure?
The variety of species in an area compared with the total number of organisms.
Approximately how many species have scientists described so far?
About 1.2 million species described, though there are ~8.7 million estimated.
What is it called when two species compete for the same resource, but neither benefits?
Interspecies competition
What’s the difference between a food chain and a food web?
A food web shows many interconnected paths, while a food chain shows one path.
What kind of adaptation is a physical body feature that improves survival?
Structural adaptation (e.g., physical features).
What two numbers are compared in the Diversity Index?
The number of species and the number of organisms.
Which ecosystems are known for the highest biodiversity?
Tropical rainforests and coral reefs.
Why is variation within a species important for survival?
It allows survival when conditions, food, diseases, or predators change.
What type of symbiotic relationship benefits both organisms?
Mutualism
What kind of adaptation involves changes in behavior?
Behavioral adaptation (e.g., migration, hunting in groups).
If a wheat field has 1,000,000 organisms across 5 species, and a forest has 750,000 organisms across 25 species, which has the higher D.I.?
The forest (25 species vs. 5 species) has a higher D.I.
Which ecosystems are known for the lowest biodiversity?
Arctic tundra and arid deserts.
What is the process called when variation leads to the formation of new species?
Speciation
What is the term for the specific role an organism plays in its ecosystem (food, predators, habitat)?
Niche
Which adaptation helped the peppered moth survive in polluted environments?
Dark-colored moths blended into soot-covered trees better.
Why might a higher D.I. indicate a healthier ecosystem?
A higher D.I. shows greater resilience and ecosystem health.
What trend in biodiversity is seen when moving closer to the equator?
Biodiversity increases closer to the equator due to heat and water availability.
Give an example of variation within a single species mentioned in the slides.
Example: Black bears vary in color (black, brown, white, gold).
Why are invasive species often so successful in new environments?
They have no natural predators/diseases, so they outcompete native species.
What process describes how the environment selects for favorable traits over time?
Natural selection (“survival of the fittest”).
How can comparing D.I. values over time help scientists?
Tracking changes in D.I. over time helps identify ecosystem stability or decline.