Ch 4: Investigations

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What role does light play in photosynthesis based on the investigations?

Primary photosynthetic pigment

Indispensable in driving photosynthetic processes (correct)

Source of water for the plant

Responsible for oxygen liberation

Which investigation emphasized the importance of carbon dioxide in photosynthesis?

Investigation 2

Investigation 4

Investigation 3 (correct)

Investigation 5

What was the purpose of covering a leaf with aluminum foil in one of the investigations?

To deprive the leaf of oxygen

To demonstrate the necessity of light in photosynthesis (correct)

To observe starch accumulation in the foil-covered portion

To block out carbon dioxide

Which pigment was highlighted for its pivotal role in photosynthesis?

Chlorophyll Signup and view all the answers

What does the glowing splint test demonstrate in one of the investigations?

Production of oxygen Signup and view all the answers

Which component was altered in the investigations to observe the effect on starch synthesis?

Carbon dioxide Signup and view all the answers

What is the most critical factor for starch accumulation in the investigations?

Adequate light Signup and view all the answers

Which substance led to the absence of starch accumulation in one of the investigations?

Sodium hydroxide Signup and view all the answers

What was the outcome of exposing plants to sodium bicarbonate in an investigation?

Led to starch synthesis Signup and view all the answers

How did scientists gain valuable insights into photosynthesis in the investigations?

By carefully manipulating variables Signup and view all the answers

Why is it necessary to destarch a plant before conducting investigations related to photosynthesis?

To ensure accurate results by removing pre-existing starch that may interfere with the findings. Signup and view all the answers

What is the purpose of the starch test in investigating photosynthetic activity?

To detect the presence of starch, a product of glucose synthesis during photosynthesis. Signup and view all the answers

How does the staining with iodine solution help in the starch test?

It confirms the presence of starch in the leaf by turning it blue-black. Signup and view all the answers

What role does chlorophyll extraction play in the starch test during investigations of photosynthesis?

It removes chlorophyll from the leaf to observe the starch presence more clearly. Signup and view all the answers

Why is the destarching process conducted by subjecting the plant to darkness for 48 hours?

To allow the plant to utilize stored starch for metabolic activities. Signup and view all the answers

Which step in the investigative process confirms the elimination of chlorophyll from the leaf in the starch test?

Staining with ethanol Signup and view all the answers

What does the blue-black coloration observed in the leaf during the starch test indicate?

The presence of starch in the leaf. Signup and view all the answers

During destarching, why is it essential to remove any pre-existing starch from the plant?

To ensure that detected starch is solely a result of photosynthetic activity. Signup and view all the answers

What effect does subjecting a leaf to boiling water have on the subsequent starch test?

It aids in chlorophyll extraction, preparing the leaf for starch detection. Signup and view all the answers

How does the ethanol treatment contribute to the accuracy of the starch test results?

It assists in extracting chlorophyll to ensure clear visualization of starch in the leaf. Signup and view all the answers

What is the purpose of subjecting a plant to darkness for 48 hours in the destarching process?

To ensure accurate test results by removing pre-existing starch Signup and view all the answers

Why is the starch test considered a reliable means of assessing photosynthetic activity?

It indicates the presence of starch synthesized during photosynthesis Signup and view all the answers

What does the blue-black coloration in the leaf indicate in the context of the starch test?

Presence of starch Signup and view all the answers

How does the subsequent staining with iodine solution contribute to the findings of the starch test?

It indicates the presence of starch in the leaf Signup and view all the answers

What function does the ethanol treatment serve in the starch test process?

It extracts chlorophyll from the leaf Signup and view all the answers

In the context of investigations on photosynthesis, what is the significance of desiccating the leaf after chlorophyll extraction?

To prepare the leaf for starch staining to detect photosynthetic activity Signup and view all the answers

Which step before the starch test ensures that chlorophyll is no longer present in the leaf?

Treating the leaf with ethanol Signup and view all the answers

How does the destarching process aid in confirming the occurrence of photosynthesis?

By decolorizing and desiccating the leaf Signup and view all the answers

What role does starch synthesis play as a byproduct of photosynthesis in investigative procedures?

It serves as an indicator of photosynthetic activity Signup and view all the answers

Which environmental factor is of utmost importance in the investigations related to photosynthesis?

Availability of carbon dioxide Signup and view all the answers

What is the purpose of covering a portion of the leaf with aluminum foil in Investigation 2?

To prevent photosynthesis from occurring in that region Signup and view all the answers

What conclusion can be drawn from the absence of starch accumulation in the foil-covered leaf in Investigation 2?

Light plays a crucial role in driving photosynthesis Signup and view all the answers

Why was sodium hydroxide used in Investigation 3 in relation to carbon dioxide?

To absorb carbon dioxide in the experiment Signup and view all the answers

What did the presence of starch accumulation in only the chlorophyll-containing regions of the variegated leaves demonstrate in Investigation 4?

The pivotal role of chlorophyll in photosynthesis Signup and view all the answers

How does the glowing splint test confirm the production of oxygen during photosynthesis in Investigation 5?

By re-igniting or intensifying the burning of the splint Signup and view all the answers

What does the absence of starch accumulation in the presence of CO2-absorbing sodium hydroxide prove in Investigation 3?

The indispensability of CO2 for photosynthetic carbon fixation Signup and view all the answers

How does the starch test specifically demonstrate the role of chlorophyll in photosynthesis?

By showing starch accumulation in chlorophyll-containing areas Signup and view all the answers

What evidence supports the claim that light drives photosynthetic processes?

The absence of starch accumulation in the foil-covered leaf Signup and view all the answers

What is the primary function of sodium bicarbonate in Investigation 3?

To release carbon dioxide for photosynthesis Signup and view all the answers

Why did the starch test only show accumulation in chlorophyll-containing regions in Investigation 4?

Chlorophyll's role as the primary photosynthetic pigment Signup and view all the answers

Why subjecting a plant to darkness for 48 hours is imperative in the destarching process?

To remove any pre-existing starch to ensure accurate results Signup and view all the answers

How does the subsequent staining with iodine solution help in the starch test?

Confirms the occurrence of photosynthesis Signup and view all the answers

What purpose does covering a portion of the leaf with aluminum foil serve in Investigation 2?

To observe the effect of light blocking on starch synthesis Signup and view all the answers

What evidence supports the destarching process aiding in confirming the occurrence of photosynthesis?

Conducting starch tests before and after destarching Signup and view all the answers

What experimental variable was manipulated in Investigation 3 to ascertain the requirement of carbon dioxide for photosynthesis?

Sodium hydroxide solution Signup and view all the answers

In the context of photosynthesis investigations, what is the significance of employing sensitive assays?

Detecting minute changes in photosynthesis Signup and view all the answers

What does the re-ignition or intensified burning of a wooden splint in the glowing splint test prove in Investigation 5?

Presence of carbon dioxide Signup and view all the answers

What does the absence of starch accumulation in the foil-covered leaf indicate in Investigation 2?

Light necessity for starch synthesis Signup and view all the answers

Which experimental variable must be altered in investigations to observe the effect on starch synthesis, as described in the text?

Light intensity Signup and view all the answers

What evidence from the investigations underscores the pivotal role of carbon dioxide in photosynthetic carbon fixation?

Sodium bicarbonate use Signup and view all the answers

Based on the text, why was aluminum foil used to cover a leaf in Investigation 2?

To obstruct light access Signup and view all the answers