IGCSE · Biology 0610 · Ecology & human influence

Populations: IGCSE Biology questions with answers

Free Populations questions for IGCSE Biology (0610), part of Ecology & human influence. Each question has the answer and the marking points an examiner would look for.

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Populations practice questions

Question 1Multiple choice · 1 markA* challenge

Yeast is grown in a flask of sugar solution. The population increases and then stays constant.
Which is a reason why the population stops increasing?

  1. A The yeast cells stop dividing because they are fully grown.
  2. B The birth rate becomes greater than the death rate.
  3. C Predators enter the flask.
  4. D Food runs out or toxic waste builds up, so the death rate equals the birth rate.
Show answer

Answer: D

Question 2Multiple choice · 1 mark

What is a community?

  1. A all the populations of different species in an ecosystem
  2. B one species in an area
  3. C a food chain
  4. D the non-living environment
Show answer

Answer: A

Question 3Multiple choice · 1 mark

Which statement describes community?

  1. A An infection passed on through sexual contact, such as HIV
  2. B All the populations of different species in an ecosystem
  3. C A group of organisms of one species living in the same area at the same time
  4. D Cell fragments involved in blood clotting
Show answer

Answer: B

Question 4Structured · 6 marksA* challenge

A population of bacteria grows in a nutrient broth.

(a)

Describe the four phases of the population growth curve.

[4]
(b)

Suggest two reasons for the death phase.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)lag, log, stationary, death
lag phase (slow) B1
log/exponential phase (rapid) B1
stationary phase (birth = death) B1
death phase (decline) B1
4
(b)nutrients run out; toxic waste
nutrients/food run out B1
build-up of toxic waste products B1
2
Question 5Structured · 3 marks

A sigmoid growth curve describes a population of rabbits introduced to an island.

(a)

Explain why the population grows slowly at first.

[1]
(b)

Explain why the population stops growing.

[2]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)few individuals reproducing
few rabbits to reproduce B1
1
(b)limiting factors: food, predators, disease
Any 2 of: limited food/space; increased predation/disease; births equal deaths B2
2
Question 6Structured · 4 marks

The size of a population is affected by several factors.

(a)

Define a population.

[1]
(b)

State three factors that affect the rate of population growth.

[3]
Show answers and mark scheme
PartAnswer and marking pointsMarks
(a)group of same species in same area
Any 1 of: a group of organisms of one species; living in the same area at the same time B1
1
(b)food supply; predation; disease; competition
food supply B1
predation B1
disease (competition, space) B1
3

More Ecology & human influence questions

Food chains, webs & energy flowNutrient cyclesFood supplyHabitat destructionPollutionConservation

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Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in