bio paper 1

Question 1

1st step of microscopy prac

Answer 1

add drop of water to clean slide

Question 2

step 2 of microscopy prac after adding drop of water to clean slide

Answer 2

add onion epidermal/human cheek cells on slide in water

Question 3

3rd step of microscopy prac after adding cells onto slide

Answer 3

highlight cells using iodine stain for onion
methylene blue for cheek

Question 4

4th step of microscopy prac after stain

Answer 4

Put cover slip on top of specimen

Question 5

1st step of viewing cells micro prac

Answer 5

place slide onto stage and clip into place

Question 6

2nd step of viewing cells micro prac after placing s/clipping slide on stage

Answer 6

select lowest power objective lens so lowest magnification

Question 7

3rd step of viewing cells micro prac after choosing lowest power objective lens

Answer 7

looking in eyepiece move stage up/down using coarse adjustment knob till image becomes more focused

Question 8

4th step of viewing cells micro prac after adjusting coarse adjustment knob

Answer 8

use fine adjustment to further focus until clear

Question 9

5th step of viewing cells micro prac after using fine-adjustment knob

Answer 9

change to higher power objective lens and refocus if higher magnification needed

Question 10

1st step on aseptic bacteria prac

Answer 10

pour hot agar into sterile petri dish and let set and cool

Question 11

2nd step of aseptic prac after pouring hot agar into sterile petri dish

Answer 11

use sterile dropping pippete to evenly spread bacteria

Question 12

3rd step of aseptic prac after using sterile dropping pippete

Answer 12

soak paper discs in diff conc of antibiotics/septics for same time and place on agar plate covered by bacteria

Question 13

4th step of asep prac after adding paper antibiotic discs to agar

Answer 13

place disk soaked in sterile water as a control

Question 14

5th step of asep prac after setting up water control disc

Answer 14

tape lid lightly on petri dish and incubate upside down on 48 hrs

Question 15

1st step of osmosis prac

Answer 15

set up test tubes w 10cm3 diff conc sucrose solution with 1 pure water as control/ one 1mol/dm3

Question 15

2nd step of osmosis prac after setting up test tubes

Answer 15

cut potato into cylinders and measure/record masses using balance

Question 16

3rd step of osmosis prac after cutting potato into cylinders

Answer 16

put a cylinder in each beaker noting which went into which tube for 24hrs

Question 17

step 4 of osmosis prac after putting cylinders into test tubes for 24 hrs

Answer 17

take cylinders out and dry with paper towels then rerecord mass

Question 18

1st step of amylase prac

Answer 18

place drop of iodine solution in each cavity of a spotting tile

Question 19

2nd step of amylase prac after dropping iodine in cavity

Answer 19

place test tube with 2cm3 amylase and 1cm3 of known ph buffer solution in 35 deg water bath

Question 20

3rd step of amylase prac after putting buffer/enzyme in 35 dg water bath

Answer 20

place another test tube with 2cm3 starch solution in water bath

Question 21

4th step of amylase prac

Answer 21

pour starch into amylase and buffer solution and start timer while all are in water bath

Question 22

5th step of amylase prac after mixing all solutions in water bath

Answer 22

every 10s add 1 drop of solution to iodine on spotting tile

Question 23

colour observation in amylase prac

Answer 23

blue black if starch is present
orange -brown if starch is digested to maltose

Question 24

what indicates faster rate of reaction in amylase prac

Answer 24

quicker it takes for spot to remain orange-brown

Question 25

6th step of amylase prac

Answer 25

repeat using diff ph buffers to see effect rate of starch breakdown

Question 26

how to prepare food test

Answer 26

crush food using pestle and mortar
dissolve some in distilled water
filter out any remaining solid using filter paper lined funnel

Question 27

reducing sugars step 1

Answer 27

add few drops of benedicts to test tube with food sample

Question 28

2nd step of reducing sugars test after adding benedick to sample

Answer 28

put test tube in water bath at 80 deg for 5 mins

Question 29

colour change in benedicks

Answer 29

blue—->green/yellow/brick red

Question 30

starch test

Answer 30

add few drops of iodine to sample and gently shake

Question 31

colour change in starch test

Answer 31

browny orange——>blue black

Question 32

protein test

Answer 32

add biuret solution to sample and shake

Question 33

colour change in protein test

Answer 33

blue—–>purple

Question 34

lipid test

Answer 34

add few drops of ethanol and distilled water to sample and shake

Question 35

colour change for lipid emulsion test

Answer 35

colourless—->cloudy white emulsion

Question 36

1st step of pondweed prac

Answer 36

add piece of fresh cut pondweed in boiling tube with sodium hydrogen carbonate solution

Question 37

2nd step of pondweed prac after adding it to boiling tube

Answer 37

place tube 10cm away from lamo

Question 38

3rd step of pondweed prac after placing tube 10cm away from lamp

Answer 38

switch on lamp and leave on 5 mins and count bubbles per min

Question 39

4th step in pondweed prac after switch on lamp for 5mins

Answer 39

repeat count 2x more to find mean bubbles per min

Question 41

6th step of pondweed prac after finding mean bub per min

Answer 41

repeat with boiling tube at diff distances to lamp

Question 42

how can you control temp gain from lamp in pondweed prac

Answer 42

-use led bulb
-put glass tank with water in between

Question 43

how do you get more accurate results in pondweed prac

Answer 43

collect o2 bubbles using inverted funnel and vol of gas using syringe