2.9 Photosynthesis

The amount of food passing into food chains can be affected by the rate of photosynthesis. Explain the effect of one limiting factor on photosynthesis.

In 1882, Engelmann investigated photosynthesis by shining light of varying wavelength on a green alga. He observed where aerobic bacteria accumulated.

[Source: Republished with permission of Oxford University Press, from Plant Physiology and Development, Sixth Edition by
Lincoln Taiz, Eduardo Zeiger, Ian M. Møller, and Angus Murphy, 2015. Permission conveyed through Copyright
Clearance Center, Inc.]

What can be deduced from this experiment?

A. Only parts of the chloroplast contained chlorophyll.

B. The distribution of bacteria indicates the action spectrum of photosynthesis.

C. Most oxygen is released from the algae in green light.

D. Chloroplasts reflect blue and red light.

In 1882, Engelmann investigated photosynthesis by shining light of varying wavelength on a green alga. He observed where aerobic bacteria accumulated.

[Source: Republished with permission of Oxford University Press, from Plant Physiology and Development, Sixth Edition by
Lincoln Taiz, Eduardo Zeiger, Ian M. Møller, and Angus Murphy, 2015. Permission conveyed through Copyright
Clearance Center, Inc.]

What can be deduced from this experiment?

A. Only parts of the chloroplast contained chlorophyll.

B. The distribution of bacteria indicates the action spectrum of photosynthesis.

C. Most oxygen is released from the algae in green light.

D. Chloroplasts reflect blue and red light.

The amount of food passing into food chains can be affected by the rate of photosynthesis. Explain the effect of one limiting factor on photosynthesis.

The amount of food passing into food chains can be affected by the rate of photosynthesis. Explain the effect of one limiting factor on photosynthesis.

Outline how photosynthesis produces glucose.

Outline how photosynthesis produces glucose.

Outline how photosynthesis produces glucose.

Explain the process of photosynthesis.

Explain the process of photosynthesis.

Explain the process of photosynthesis.

State a suitable solvent for extracting photosynthetic pigments from plant tissue.

State a suitable solvent for extracting photosynthetic pigments from plant tissue.

State a suitable solvent for extracting photosynthetic pigments from plant tissue.

Explain how the pigments in the chromatogram of spinach are identified.

Explain how the pigments in the chromatogram of spinach are identified.

Explain how the pigments in the chromatogram of spinach are identified.

Outline what happens when spinach extract is spotted on a TLC plate and placed into a container of solvent.

Outline what happens when spinach extract is spotted on a TLC plate and placed into a container of solvent.

Outline what happens when spinach extract is spotted on a TLC plate and placed into a container of solvent.

Explain what the R_f values represent in chromatography.

Explain what the R_f values represent in chromatography.

Explain what the R_f values represent in chromatography.

State two photosynthetic pigments that could be identified using chromatography.

State two photosynthetic pigments that could be identified using chromatography.

State two photosynthetic pigments that could be identified using chromatography.

The graph shows the effect of increasing light intensity on the rate of CO₂ uptake by a species of green plant maintained in conditions of constant temperature and CO₂ concentration.

[Source: © International Baccalaureate Organization 2019]

Which statement is consistent with the graph?

A. Photosynthesis stops at high light intensity.

B. Rates of photosynthesis increase with temperature.

C. Cell respiration leads to net production of CO₂ at low light intensity.

D. There is a negative correlation between CO₂ uptake and light intensity.

The graph shows the effect of increasing light intensity on the rate of CO₂ uptake by a species of green plant maintained in conditions of constant temperature and CO₂ concentration.

[Source: © International Baccalaureate Organization 2019]

Which statement is consistent with the graph?

A. Photosynthesis stops at high light intensity.

B. Rates of photosynthesis increase with temperature.

C. Cell respiration leads to net production of CO₂ at low light intensity.

D. There is a negative correlation between CO₂ uptake and light intensity.

The graph shows the absorption spectra of chlorophyll a and chlorophyll b.

[Source: adapted from F. P. Zscheile and C. L. Comar, 'Influence of Preparative Procedure on the Purity of Chlorophyll
Components as Shown by Absorption Spectra.' Int. J. Plant Sciences, Volume 102, Number 3, Mar., 1941, pp. 463–481.
Used with the kind permission of University of Chicago Press.]

What can be concluded from the graph?

A. Both chlorophyll a and chlorophyll b absorb a large amount of green light

B. Chlorophyll b absorbs red light more efficiently than blue light

C. Other pigments must absorb light between blue and red in the spectrum

D. Chlorophyll a and chlorophyll b have different absorption peaks

The graph shows the absorption spectra of chlorophyll a and chlorophyll b.

[Source: adapted from F. P. Zscheile and C. L. Comar, 'Influence of Preparative Procedure on the Purity of Chlorophyll
Components as Shown by Absorption Spectra.' Int. J. Plant Sciences, Volume 102, Number 3, Mar., 1941, pp. 463–481.
Used with the kind permission of University of Chicago Press.]

What can be concluded from the graph?

A. Both chlorophyll a and chlorophyll b absorb a large amount of green light

B. Chlorophyll b absorbs red light more efficiently than blue light

C. Other pigments must absorb light between blue and red in the spectrum

D. Chlorophyll a and chlorophyll b have different absorption peaks

Discuss briefly whether the detection of starch in this experiment was proof that photosynthesis had occurred in the leaf.

Suggest how a plastic bag placed around the plant pot prevents carbon dioxide from reaching the plant’s leaves.

Discuss briefly whether the detection of starch in this experiment was proof that photosynthesis had occurred in the leaf.

Discuss briefly whether the detection of starch in this experiment was proof that photosynthesis had occurred in the leaf.

Suggest how a plastic bag placed around the plant pot prevents carbon dioxide from reaching the plant’s leaves.

Suggest how a plastic bag placed around the plant pot prevents carbon dioxide from reaching the plant’s leaves.

A chromatograph was made of the photosynthetic pigments of a leaf of the plant.

[Source: Adapted from “Diversity of Photosynthetic Pigments” by Alexander F. Motten in Tested Studies for
Laboratory Teaching, Volume 16 of the Association for Biology Laboratory Education and used by permission of the
author.]

Outline what measurements would be taken to identify pigment X.

A chromatograph was made of the photosynthetic pigments of a leaf of the plant.

[Source: Adapted from “Diversity of Photosynthetic Pigments” by Alexander F. Motten in Tested Studies for
Laboratory Teaching, Volume 16 of the Association for Biology Laboratory Education and used by permission of the
author.]

Outline what measurements would be taken to identify pigment X.

A chromatograph was made of the photosynthetic pigments of a leaf of the plant.

[Source: Adapted from “Diversity of Photosynthetic Pigments” by Alexander F. Motten in Tested Studies for
Laboratory Teaching, Volume 16 of the Association for Biology Laboratory Education and used by permission of the
author.]

Outline what measurements would be taken to identify pigment X.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

Explain the effect of temperature on the rate of photosynthesis in this mesocosm.

The apparatus shown was used to investigate the effect of varying carbon dioxide concentration on the rate of photosynthesis. Carbon dioxide concentrations were varied by adding different amounts of sodium hydrogen carbonate (NaHCO₃) to water.

What is the dependent variable in this investigation?

A. Temperature

B. Light intensity

C. Amount of NaHCO₃ added

D. Volume of oxygen produced

The apparatus shown was used to investigate the effect of varying carbon dioxide concentration on the rate of photosynthesis. Carbon dioxide concentrations were varied by adding different amounts of sodium hydrogen carbonate (NaHCO₃) to water.

What is the dependent variable in this investigation?

A. Temperature

B. Light intensity

C. Amount of NaHCO₃ added

D. Volume of oxygen produced

Describe how leaf cells make use of light energy.

Describe how leaf cells make use of light energy.

Describe how leaf cells make use of light energy.

Describe how plants affect the amount of carbon dioxide in the atmosphere.

Describe how plants affect the amount of carbon dioxide in the atmosphere.

Describe how plants affect the amount of carbon dioxide in the atmosphere.

The micrograph shows part of a chloroplast.

_{[Source: Newcomb, E., n.d. [Detail of a chloroplast]. [image online] Available at: https://search.library.wisc.edu/digital/
AHDTZ7JMHZ5VSU8C [Accessed 1 October 2021] © Board of Regents of the University of Wisconsin System.
Licensed under the Creative Commons Attribution 4.0 International. https://creativecommons.org/licenses/by/4.0/
deed.en.]}

What reaction takes place in region P?

A.  Carboxylation of ribulose bisphosphate

B.  Photolysis of water molecules

C.  Generation of ATP by ATP synthase

D.  Reduction of NAD in Photosystem I

The micrograph shows part of a chloroplast.

_{[Source: Newcomb, E., n.d. [Detail of a chloroplast]. [image online] Available at: https://search.library.wisc.edu/digital/
AHDTZ7JMHZ5VSU8C [Accessed 1 October 2021] © Board of Regents of the University of Wisconsin System.
Licensed under the Creative Commons Attribution 4.0 International. https://creativecommons.org/licenses/by/4.0/
deed.en.]}

What reaction takes place in region P?

A.  Carboxylation of ribulose bisphosphate

B.  Photolysis of water molecules

C.  Generation of ATP by ATP synthase

D.  Reduction of NAD in Photosystem I