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Biology 30 · Worksheets

Populations · Set B

Ten questions of mixed difficulty, covering Populations. Print it, or work through it on screen — the answer key starts on its own page.

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Populations · Set B

Biology 30 · maddyhelps.com

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Circle the best answer for each question. Show your work in the space provided.

  1. A population grows from 400 to 460 in one year. What is its per capita growth rate?

    1. a) 1.15
    2. b) 0.15
    3. c) 0.13
    4. d) 60

  2. In a population, the frequency of the recessive allele q is 0.3. What is p?

    1. a) 0.09
    2. b) 0.3
    3. c) 0.49
    4. d) 0.7

  3. Competition between members of the same species is called:

    1. a) interspecific competition
    2. b) intraspecific competition
    3. c) mutualism
    4. d) predation

  4. 16% of a population shows a recessive trait. What is the frequency of the recessive allele, q?

    1. a) 0.84
    2. b) 0.32
    3. c) 0.16
    4. d) 0.4

  5. Succession that begins on bare rock with no soil is called:

    1. a) primary succession
    2. b) a bottleneck
    3. c) secondary succession
    4. d) a climax community

  6. A relationship in which both species benefit is called:

    1. a) commensalism
    2. b) parasitism
    3. c) mutualism
    4. d) predation

  7. Snowshoe hare and lynx populations rise and fall in cycles. Why does the lynx peak come shortly after the hare peak?

    1. a) The two species have nothing to do with each other
    2. b) Lynx numbers respond to food supply, so they lag behind the hares
    3. c) Lynx eat less when hares are plentiful
    4. d) Hares hunt lynx when their numbers are high

  8. Which set of traits describes a K-selected species?

    1. a) Short lifespan, early reproduction, boom-and-bust numbers
    2. b) Many offspring, little parental care, rapid growth
    3. c) Few offspring, lots of parental care, population near carrying capacity
    4. d) Many offspring, no parental care, lives in unstable habitats

  9. Lichens are often the first organisms to grow on bare rock. They are called:

    1. a) invasive species
    2. b) climax species
    3. c) keystone species
    4. d) pioneer species

  10. A J-shaped growth curve shows:

    1. a) a population crash
    2. b) logistic growth
    3. c) a stable population
    4. d) exponential growth

Answer key · Populations · Set B

Biology 30 · maddyhelps.com

  1. b) 0.15 — cgr = ΔN ÷ N = (460 − 400) ÷ 400 = 60 ÷ 400 = 0.15. Dividing by the new size (460) gives 0.13, which is wrong.
  2. d) 0.7 — p + q = 1, so p = 1 − 0.3 = 0.7. 0.09 is q², the frequency of the recessive genotype.
  3. b) intraspecific competition — Intra- means within: two wolves competing for a mate. Inter- means between, like wolves and coyotes competing for deer.
  4. d) 0.4 — The recessive trait only shows in homozygous individuals, so q² = 0.16. Take the square root: q = 0.4. Using 0.16 as q is the classic trap.
  5. a) primary succession — Primary succession starts from nothing, like rock after a glacier retreats. Secondary succession starts where soil survived, like after a forest fire.
  6. c) mutualism — Mutualism is +/+, like bees and flowers. Commensalism is +/0, and parasitism is +/−.
  7. b) Lynx numbers respond to food supply, so they lag behind the hares — More hares means more food for lynx, which then reproduce — but that takes time. Once lynx are plentiful, hare numbers drop, and lynx follow them down.
  8. c) Few offspring, lots of parental care, population near carrying capacity — K-selected species, like elephants and humans, invest heavily in a few young and stay near K. The other options describe r-selected species, like mice or insects.
  9. d) pioneer species — Pioneer species break rock down and add organic matter, slowly building the first soil so that mosses and plants can follow.
  10. d) exponential growth — A J-curve keeps getting steeper because growth is unlimited. An S-curve (logistic) levels off at carrying capacity.