B6

Question 1

How could you use quadrats to estimate the size of a population in an area?

Answer 1

Population = Number counted x (total survey area/ area sampled)

Question 2

What methods could you use to sample animals?

Answer 2

• capture -recapture

- pooters, net and keys

Question 3

What are pooters, how do they work and what can they do?

Answer 3

Pooters are jars that have rubber bungs sealing up the top,
Suck over the shorter tube and put the end of the longer tube over an insect.
They collect ground insects.

Question 4

A student wants to find out which ground insects are present in two different areas of a woodland over a 24-hour period. Suggest a method the student could use to sample the area.

Answer 4

The student could set up and leave a pitfall trap in each area of the woodland overnight. Insects present in the traps could be counted the next day and could be compared with other traps.

Question 5

In a survey of a 100m2 area, you count a total of 30 dandelions in 10 quadrats. The quadrats have sides of 0.5m. Estimate the total population size in this area.

Answer 5

[100m2/ (10 x 0.5^2) ] x 30 = 1200

Question 6

What is a key?

Answer 6

A series of questions that you can use to figure out what a unknown organism is.

Question 7

Give two abiotic factors that might be measured on a sandy shore.

Answer 7

Air temperature, sand temperature, sand moisture level, sand pH.

Question 8

Give an example of a Biotic factor that can affect the distribution of organisms.

Answer 8

-Competition between species

Question 9

List the methods that you could use to measure soil pH.

Answer 9

• universal indicator liquid

- electronic pH monitors

Question 10

Describe how the construction of houses on a meadow could reduce biodiversity.

Answer 10

• destruction of habitats

- reduce number of living species; biodiversity

Question 11

A student estimates the number of snails in a pond.
Part of his method involves collecting snails and marking them.
What is the name of the method that he is using?

Answer 11

Capture-Recapture.

Question 12

Describe how monoculture could reduce biodiversity.

Answer 12

Only a single crop is grown; habitats are cleared to make way for the large fields.

Question 13

Explain how industrial development can cause pollution.

Answer 13

• Sewage and toxic chemicals from industry pollute water bodies, affecting organisms relying on it for survival.
• Smoke and gases pollute air; sulfur dioxide causes acid rain

Question 14

How can hunting potentially create a negative impact on our food chains?

Answer 14

• too many individuals killed can lead to extinction
• -reduces biodiversity
• –knock-on effects
• —create negative impact on biodiversity