Unit 8 check
Unit 8 check: Ecology
10 questions from 7 lessons in Unit 8. Answer each one, and if you miss, follow the link back to where it is taught, then try again. Your score counts first tries.
Question 1 · from 8.1 · Sort it
Each card describes how an organism responds to a change in its environment. Tap a card, then the kind of response it is.
Behavioral
Physiological
Question 2 · from 8.2 · Sort it
Each card names a place where carbon is stored. Tap a card, then whether it is an abiotic or a biotic reservoir.
Abiotic reservoir
Biotic reservoir
Question 3 · from 8.3 · Fill the statement
Complete the description of a population that reproduces without constraints.
Its growth is . In the equation dN/dt = r_max N, the number added per unit of time gets as N gets larger, and a graph of N against time curves more and more steeply.
Setup for question 4
Two new situations, both teaching examples. First, rank three populations of one species with the same r_max and carrying capacity by how fast they grow. Second, decide how a fish population grows after a flood leaves it far below its carrying capacity.
Question 4 · from 8.4 · Rank it
Three populations of one species each have r_max = 0.2 per year and a carrying capacity K = 500. Population A holds 100 individuals, population B holds 250 and population C holds 480. Using dN/dt = r_max N ((K − N)/K), rank them by dN/dt, from fastest growing to slowest growing.
Fastest growing first
Give each one a place, 1 for first. Give two the same place if they are equal.
Your ranking: none yet
Setup for question 5
Two new situations, both teaching examples. First, put the events of a predator and prey model in order. Second, predict what happens to one beetle species when a competing species is removed from a field.
Question 5 · from 8.5 · Put it in order
In a model of a predator and its prey, the prey population starts small and its food is plentiful. Put the events in order, from first to last.
Setup for question 6
Researchers sow two grassland plots of the same size. Plot A gets 2 plant species; plot B gets 12. They weigh the plant mass in each plot (grams per square meter) just before a severe drought and again just after it. These numbers are a teaching example.
| Plot | Plant species | Mass before (g/m²) | Mass after (g/m²) |
|---|---|---|---|
| A | 2 | 400 | 160 |
| B | 12 | 420 | 336 |
Question 6 · from 8.6 · Calculate
Using the table: what percentage of its plant mass from before the drought did plot B still have after it?
Setup for question 7
In a region where a leaf fungus is common, researchers follow plants of one species with three genotypes at one gene. For each genotype they record the average number of offspring per plant that survive to reproduce. These numbers are a teaching example.
| Genotype | Average surviving offspring per plant |
|---|---|
| AA | 3.0 |
| Aa | 4.5 |
| aa | 1.2 |
Question 7 · from 8.7 · Calculate
Using the table: what is the relative fitness of genotype AA, taking the fittest genotype as 1? Give your answer to two decimal places.
Question 8 · from 8.1 · Match
Match each kind of signal to an example of it.
Question 9 · from 8.2 · Match
Match each process to what happens during it.
Setup for question 10
Two new situations, both teaching examples. First, sort changes in a population's births and deaths by their effect on dN/dt. Second, decide whether a student is right about how a bacterial population grows without constraints.
Question 10 · from 8.3 · Sort it
Each card describes one change to a population, with everything else staying the same. Tap a card, then its effect on dN/dt.
Raises dN/dt
Lowers dN/dt
0 of 10 answered.