Lesson 5.1

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Which of the following is true in a climax community?

1. the community will constantly evolve and change
2. if one species dies, a new species will fulfil the same role
3. They are stable for a long time, with the same species maintaining their population
4. it goes through a major change called "climax" every few hundred years

As succession progresses, animal species diversity increases due to the fact that

1. less soil is being created
2. food choices increase
3. precipitation rates stabilize
4. temperatures moderate

What type of succession does this picture show?

1. Primary succession
2. Secondary succession

Measuring population

Size and density

Why?

• Knowing if population is increasing or decreasing
  - Useful for predicting future developments 
  - Understanding if conservation is working

How?

• Ideally exact numbers, but total count is often not possible
• Therefor, estimates of size
• Method used for estimates mainly depends on the type of organism
• Plants/ not very mobile animals: quadrat or transect (first video)
• Mobile animals: mark-recapture (second video)

What is a square called that we use to sample populations?

1. grid
2. quadrat
3. cube
4. quarter

These four 1m2 squared quadrats were place in a 8m2 garden. Estimate the total population of flowers in the whole garden.

1. 16
2. 8
3. 40
4. 20

Which one of these is a correct assumption you need to make about a population between samplings?

1. It is a closed population
2. It won't rain between samplings
3. There are lots of deaths
4. There are lots of births

If 50 crabs were captured and marked and then released and then a few days later 25 were caught and of those 5 were marked. What would the estimate of the population be?

1. 500
2. 250
3. 75
4. 200

Homework

- Complete the lessonup

- Read pages 450-451

- Complete PO part 3: measuring populations