Population Ecology is one of 10 topics in the Grade 12 Life Sciences CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. A population with unlimited resources and no limiting factors typically shows which growth curve shape?
A J-shaped (exponential) curve
An S-shaped (sigmoid) curve
A perfectly flat, horizontal line
A downward-sloping curve
Answer: A J-shaped (exponential) curve — Without limiting factors, a population can grow exponentially, producing a J-shaped curve that accelerates continuously over time.
Easy
2. The maximum population size that a given environment can sustainably support is called the:
Carrying capacity
Population density
Growth rate
Limiting factor
Answer: Carrying capacity — Carrying capacity (K) is the maximum population size an environment can sustainably support given its available resources.
Medium
3. An S-shaped (sigmoid) population growth curve differs from a J-shaped curve mainly because it shows:
Growth slowing and levelling off as the population approaches carrying capacity, due to limiting factors
Growth that never slows down at any point
No initial slow (lag) phase at all
A population that shrinks continuously from the start
Answer: Growth slowing and levelling off as the population approaches carrying capacity, due to limiting factors — Unlike the unrestricted J-curve, the S-curve reflects real-world limiting factors: growth slows and stabilises as the population nears the environment's carrying capacity.
