Of Populations Flashcards
7 cards from real Ecology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Of Populations flashcards as text
Which sampling method is most appropriate for estimating the density of a sessile (non-moving) plant population?
Answer: Quadrat sampling
Quadrat sampling counts individuals within randomly placed plots, making it ideal for immobile organisms like plants.
Boom-and-bust population cycles are most characteristic of which life history type?
Answer: r-selected species in variable or disturbed environments
r-selected species reproduce rapidly, leading to explosive population growth followed by crashes when resources are exhausted.
The term 'effective population size' (Ne) differs from census population size (N) because Ne:
Answer: Counts only reproductive-age adults and adjusts for unequal sex ratios and variance in reproductive success
Effective population size accounts for factors like skewed sex ratios and variation in offspring number, and is often much smaller than the actual census count.
Which pattern of population dispersion is most commonly observed in nature and often results from random resource availability?
Answer: Clumped
Clumped dispersion is the most common pattern, arising because resources are often patchy and social behaviors attract individuals to the same areas.
Density-dependent factors regulate population size by:
Answer: Acting more strongly as population density increases, creating negative feedback
Density-dependent regulation intensifies as populations grow, acting as negative feedback that pushes populations back toward carrying capacity.
In a life table, the term 'lx' represents:
Answer: The probability of surviving from birth to age x
lx (survivorship) is the proportion of individuals from a cohort that survive from birth to age class x.
What is the primary ecological consequence of a population experiencing exponential growth for an extended period?
Answer: Overshoot of carrying capacity followed by a population crash
Prolonged exponential growth causes populations to exceed their carrying capacity, depleting resources and triggering a subsequent die-off.