EXPERIEMENT (TESTS)

Question 1

glucose (reducing sugar):

1. chemicals / instrument,
2. positive result / function.

Answer 1

1. benedicts solution & 37˚C water bath

2. sky blue to brick red

Question 2

protein (biuret)

1. chemicals / instrument,
2. positive result / function.

Answer 2

1. Biuret solution (sodium hydroxide & copper sulphate)

2. sky blue to lilac

Question 3

strach

1. chemicals / instrument,
2. positive result / function.

Answer 3

1. iodine

2. brown to blue/black

Question 4

fat

1. chemicals / instrument,
2. positive result / function.

Answer 4

1. brown paper

2. translucent spot

Question 5

animal cell (cheek cell)

1. chemicals / instrument,
2. positive result / function.

Answer 5

1. stain: methylene blue

2. highlight cell organelles under microscope

Question 6

plant cell (onion cell)

1. chemicals / instrument,
2. positive result / function.

Answer 6

1. stain: iodine

2. highlight cell organelles under microscope

Question 7

cells

1. chemicals / instrument, (3)
2. positive result / function. (3)

Answer 7

1. cover slip at 45˚ angle - 2. to prevent air bubbles
2. mounted needle - 2. helps lower cover slip slowly at 45˚ angle
3. drops of water on slide - 2. to prevent cells drying out

Question 8

microscope

1. chemicals / instrument, (2)
2. positive result / function. (2)

Answer 8

1. objective lense - 2. magnifies object to be observed

1. coarse focus wheels - 2. roughly focuses image

Question 9

enzyme activity

1. chemicals / instrument,
2. positive result / function.

Answer 9

1. hydrogen peroxide (substrate), catalase (enzyme in celery)
2. oxygen in the form of foam (volume of foam per unit time)

Question 10

temperature variation (enzymes)

1. chemicals / instrument,
2. positive result / function.

Answer 10

1. thermostatically controlled waterbath at different temperatures
2. changing temerature will vary the amount of foam produced (eg enzyme activity will change)

Question 11

pH variation (emzymes)

1. chemicals / instrument,
2. positive result / function.

Answer 11

1. pH buffer solutions of various pH

2. change buffer pH will effect enzyme activity (i.e. change amount of oxygen in the form of foam produced)

Question 12

1. washing up liquid (enzymes)

2. positive result / function

Answer 12

2. traps oxygen in the form of foam and allows oxyen production (enzyme activity )to be measured

Question 13

enzyme immobilisation (enzymes)

1. chemicals / instrument, (3)
2. positive result / function. (3)

Answer 13

1. sodium alginate -2. inert material that traps enzyme
2. calcium chloride -2. material that makes enzyme insoluble
3. yeast -2. sourse of enzyme sucrase

Question 14

photosynthesis

1. chemicals / instrument,
2. positive result / function.

Answer 14

1. elodea (aquatic plant)

2. easier to see and count oxygen bubbles given off

Question 15

CO2 variation (photosynthesis)

1. chemicals / instrument,
2. positive result / function.

Answer 15

1. sodium hydrogen carbonate

2. varying the amount will vary the CO2 concentration and change the number of bubbles of O2produced

Question 16

light intensity variation (photosynthesis)

1. chemicals / instrument,
2. positive result / function.

Answer 16

1. lamp

2. moving the light source different distances from experiment will vary O2 bubbles produced

Question 17

temperature maintainence (photosynthesis)

1. chemicals / instrument,
2. positive result / function.

Answer 17

1. thermostatically controlled waterbath at a fixed temperature
2. keeps temperature constant

Question 18

ethanol test (respiration)

1. chemicals / instrument,
2. positive result / function.

Answer 18

1. potassium iodide / sodium hypochlorite, heat gently in a water bath
2. yellow crystals

Question 19

carbon dioxide test (respiration)

1. chemicals / instrument,
2. positive result / function.

Answer 19

1. limewater

2. clear to milky

Question 20

abiotic factor (ecology)

1. chemicals / instrument, (4)
2. positive result / function. (4)

Answer 20

1. pH metre -2. meaure pH of soil
2. thermometre -2. measure soil and air temperature
3. anemometre -2. measure wind speed
4. secchi disc / turbidity metre -2. measure water turbidity

Question 21

qualitative analysis

1. chemicals / instrument, (7)
2. positive result / function. (7)

Answer 21

1. identification key -2. series of questions used to identify animals and plants
2. pooter -2. collects insects and spiders
3. beating tray -2. collects insects, spiders, caterpillars
4. pitfall trap -2. crawing insects, snails
5. sweep net -2. hedgerow insects
6. tullggren funnell -2. centipedes, millipedes
7. quadrat -2. record the number of times a plant appears

Question 22

osmosis

1. chemicals / instrument,
2. positive result / function.

Answer 22

1. visking tubing

2. acts as a semi-permeable membrane

Question 23

dicot stem analysis

1. chemicals / instrument, (2)
2. positive result / function. (2)

Answer 23

1. blade / scalpel -2. cut a thin slice of celery

1. forcep -2. transfer stem to glass slide

Question 24

leaf yeasts (fungi)

1. chemicals / instrument,(4)
2. positive result / function. (4)

Answer 24

1. petroleum jelly -2. sticks leaf to lid of agar plate
2. nutrient agar -2. medium with all the food microorganisms need to grow
3. methylates spirits -2. kills any microorganisms present
4. incubator at 35˚C -2. temperature at which enzymes in yeast work best.

Question 25

DNA isolation 1. chemicals / instrument, (8) 2. positive result / function. (8)

Answer 25

1. washing up liquid -2. cell membrane breaks down 1. table salt -2. DNA molecules clump together 1. water bath at 60˚C (no longer than 15 minutes) -2. speeds up reaction and denatures enzyme DNase that breaks down DNA (or DNA will start to break down ) 1. icebath -2. prevents complete denaturation and DNA destruction 1. food blender -2. breaks down cell wall 1. filter paper -2. collects cell fragments 1. protease -2. breaks down protein surrounding DNA 1. ice cold ethanol -2. causes the DNA to come out of solution

Question 26

germiation 1. chemicals / instrument, (2) 2. positive result / function. (2)

Answer 26

1. boiled water -2. to remove oxygen from water | 1. layer of oil -2. eliminate oxygen (creates anaerobic conditions)

Question 27

growth regulators 1. chemicals / instrument, 2. positive result / function.

Answer 27

1. IAA (indole acetic acid) 2. affects the length of the root and shoot growth - at low concentration promotes root growth, at hight concentration promotes shoot growth