Population size, distribution, growth, and regulation.
Test your knowledge with these top questions!
In a classic predator-prey cycle, which population peaks first?
Prey numbers climb first, then well-fed predators multiply and drive prey back down.
What happens when deer exceed their habitat's carrying capacity?
Overgrazed deer herds often crash after stripping plants, so fewer fawns survive the winter.
Why does yeast growth in a sealed bottle level off over time?
Yeast cells produce alcohol as waste, which slows and then stops their own growth.
Which big cat has very low genetic diversity from an ancient bottleneck?
Cheetahs match so closely that skin grafts between strangers are often accepted.
What does a population bottleneck sharply reduce within a species?
Only the survivors' gene variants remain, so rare variants are often lost for good.
Which condition keeps a mark-and-recapture population estimate accurate?
Even mixing makes the second catch representative; clustering, migration, or lost tags skew the proportion.
What sets the carrying capacity of a fish pond?
Adding food can raise a pond's limit until oxygen or space runs out instead.
The basic two-sample mark-and-recapture calculation estimates what about wild animals?
The share of marked animals in a later catch mirrors the whole group, revealing how many animals were never caught.
Researchers mark 20 trout, later catch 50 trout, and find 10 marked. What is the estimated population?
Multiply 20 marked fish by 50 caught later, then divide by 10 recaptured marks to scale up to 100.
Why do snowshoe hares grow white coats each winter?
White fur hides hares against snow, but shorter winters now leave them mismatched and easier to catch.