Floating leaf disk assay lab answers

Photosynthesis Is The Process In Which Plants Take Sunlight Energy And Convert Into Chemical Energy (ATP). Using Special Organelles Called Chloroplasts; Plants Will Undergo A Conversion That Results In The Formation Of ATP, A Carbohydrate And Oxygen. Th

This is a Lab report quiz questions. I will send the Lab experiement result that you use to answer this questions. Please I need a straight answers and orderly according to the questions. I expect a excellent Lab report answers. The Lab experiment and result is attached below the questions.

1. Calculate the % number of disks floating (%NDF) for each of the Control (water) and Treatment groups (NaHCO3). (2 pts.) This information may be placed in a Table using Microsoft Excel or Microsoft Word.

show your work!
refer to the class notes re: how to do this…

2. Neatly graph experimental results. (2 pts.)

graph paper and add a title and a legend to the graph
Microsoft Excel

3. What was the overarching QUESTION addressed by the lab exercise? (0.5 pt.)

4. State “null” (H0) and “alternative” (HA) HYPOTHESES. (0.5 pt.)

5. State your PREDICTION in “If…., then…” format, and based upon your knowledge of Photosythesis

from our class discussion. (0.5 pt.)

6. As a follow-on to the previous question and in the context of the experiment you performed in class…Aside from affecting “aesthetics” and habitat for animals, why are plant and conservation scientists worried about the effects of “clear cutting” (i.e., cutting down forests for development) in combination with rising CO2 levels? (2 pts.)

Photosynthesis Student Guide

Photosynthesis is the process in which plants take sunlight energy and convert into chemical energy (ATP). Using special organelles called chloroplasts; plants will undergo a conversion that results in the formation of ATP, a carbohydrate and oxygen. The oxygen is released into the atmosphere as a byproduct. Plants are classified as autotrophs because they make organic molecules like glucose from inorganic carbon dioxide.

The formula for photosynthesis is as follows:

12H2O + 6CO2 6O2 +C6H12O6 + 6H2O

In today’s lab, you will perform a leaf disk assay. First, you will carve leaf disks from plants located on the lab bench and place them in a chamber. One chamber will contain distilled water, while the other chamber will contain sodium bicarbonate. Next, you will evacuate the chamber of all gases. Your leaf disks should sink. Can you explain why they sink? As photosynthesis takes place, your leaf disks should float. Make sure that you can explain why they float.

Activity: Leaf Disk Assay

1. Obtain 2 syringes. Label them 1 and 2.

2. Separate the plungers from the bodies.

3. Cut 10 leaf disks|strips from the plants.

4. Place the 10 disks into Chamber 1 and replace the plunger.

5. Obtain 20 mL dH2O in a 50 mL beaker.

6. Expel the air – see handout on table.

7. Leaf disks|strips should sink.

8. Repeat steps for chamber 2, but use sodium bicarbonate instead of water.

9. Place chambers in front of light bank.

10. At 2 minute intervals for 20 minutes invert chambers and return them. Count the number of disks floating.

Notes:

Leaf disks|strips should sink once oxygen has been removed from the chamber. As photosynthesis takes place, disks|strips float once again. The time required for a disk to float is an index of the net rate of photosynthesis (oxygen produced by photosynthesis – oxygen consumed during aerobic respiration).

ET = Elapsed Time

NDF – Number of Disk|Strips Floating

% = NDF\10 x 100.

Activity: Generate a hypothesis (educated guess) about what you believe will happen in each chamber.

Quiz Assignment (Take home)

Due: Beginning of the next wet lab. Your graph should be placed on graph paper and answers to questions must be typed.

Please Use this formula:

Sunlight

CO2 + H2O C6H12O6 + H2O + O2

1. Calculate the % number of disks floating (%NDF) for each of the Control (water) and Treatment groups (NaHCO3). (2 pts.) This information may be placed in a Table using Microsoft Excel or Microsoft Word.

· show your work!

· refer to the class notes re: how to do this…

2. Neatly graph experimental results. (2 pts.)

· graph paper and add a title and a legend to the graph

· Microsoft Excel

3. What was the overarching QUESTION addressed by the lab exercise? (0.5 pt.)

4. State “null” (H0) and “alternative” (HA) HYPOTHESES. (0.5 pt.)

5. State your PREDICTION in “If…., then…” format, and based upon your knowledge of Photosythesis

from our class discussion. (0.5 pt.)

6. As a follow-on to the previous question and in the context of the experiment you performed in class…Aside from affecting “aesthetics” and habitat for animals, why are plant and conservation scientists worried about the effects of “clear cutting” (i.e., cutting down forests for development) in combination with rising CO2 levels? (2 pts.)

Lab experiment result:

Time (min)

Treatment group

NaHCO3

% NDF

Control group

H2O

% NDF

2

All leaves at the bottom

0%

No float

0%

4

3 leaves float on top

30%

No float

0%

6

6 leaves float on top

60%

No float

0%

8

7 leaves float on top

70%

No float

0%

10

9 leaves float on top

90%

No float

0%

12

9 leaves float on top

90%

No float

0%

14

9 leaves float on top

90%

No float

0%

16

9 leaves float on top

90%

No float

0%

18

10 leaves float on top

100%

No float

0%

20

10 leaves float on top

100%

No float

0%

Please use this result to answer all the questions.

Sunlight

PAGE

Delaney-Tucker\K. Major