Topic 5

Question 1

Ecological sampling IV,DV, CV

Answer 1

IV - distance along transect
DV - soil depth
CV - soil temp, person measuring, equipment

Question 2

Ecological sampling method

Answer 2

Place 15m transect across grass
Place left corner of 25 quadrat at each metre
Measure longest blade of grass in the middle sequence using a ruler
Measure soil depth
Repeat
Measure soil temp

Question 3

Brine shrimp IV,DV,CV

Answer 3

IV -temp
DV - number hatched
CV - light intensity, pH, salt content, oxygen conc

Question 4

Brine shrimp method

Answer 4

Range of temps 5-35C
Add 20cm of water
Label beaker with temp 
Place tiny pinch of eggs cyst onto a large sheet of white paper
Count out 40 eggs
Wet a piece of graph using salt water 
Put paper with 40 eggs into tube, after 3 mint use forceps to remove paper
Repeat for each temp

Question 5

Hill reaction

Answer 5

Cut three spinach leaves and add to cold isolating medium
Grind and place muslin over a funnel using cold isolation medium
Filter mixture and ring muslin
Pour into centrifuge tubes in ice cold water - same volume
Centrifuge to get a pellet and pour off liquid (supernatant) into a tube - resuspend the pellet with isolation medium using a glass rod
Store leaf extract in ice cold salt water
Add DCID and shake - time how long it takes to decolourise

Question 6

Why does DCPIP change colour?

Answer 6

DCPIP accepts electron