Posted: February 28th, 2023

PLANT PHYSIOLOGY

Study / exam questions (understanding and comprehension) – Due Feb 18, 2023

· True or False: Land plants are monophyletic (they descend from a single ancestor)

· Diagram the family tree of living organisms, indicating the two major endosymbiotic events that occurred in the eukaryotic lineages

· Which one of the following statements is true?

· Light energy induces the breakdown of chlorophyll to form glucose and oxygen as products.

· Chlorophyll absorbs light energy and then transfers the energy to electrons that drive the formation of glucose from carbon dioxide.

· Chlorophyll acts as a catalyst to bond carbon dioxide molecules together when activated by light

· Light energy enters chlorophyll, which triggers a chemical reaction between water and carbon dioxide to form glucose.

· Name two ways that a plant might use the products of photosynthesis

· Will rising atmospheric CO2 levels, all other effects aside, preferentially benefit C3 or C4 plants? Explain your answer.

· The rate of transpiration from a desert cactus is minimal at noon, even though water is evaporating maximally from the surrounding soil. Why and how?2

· In what ways did the evolution of lignin affect plant the green plant lineage?

· What are plasmodesmata and what functions do they have?

· What are three types of molecules carried in the xylem? The phloem?

· In what ways is the flow of water through a plant regulated at the point of entry and exit?

· Give an example of a mechanism for desiccation avoidance and for one for desiccation tolerance.

Discussion questions (engagement and connections)

· How do prokaryotic and eukaryotic cells differ, and what is the adaptive value of the eukaryotic cell structures?

· In what ways is life easier for aquatic algae than plants? In what ways do algae support human survival, and in what ways do plants support our survival?

· Would a plant that lost its ability to make chlorophyll be able to survive? Why or why not? What would happen to a plant if it no longer had access to CO2?

· The conversion of solar energy to chemical energy that takes place during photosynthesis in plants and bacteria is the inspiration for the development of artificial photosynthesis. What is artificial photosynthesis? How might this technology alleviate our dependence on fossil fuels?

[There is lots of information available, but here are a few places you can start: (
http://www.rsc.org/images/Solar-fuels_tcm18-

221433 ) or here (
http://solarfuelshub.org/research/) or here

(
http://newscenter.lbl.gov/news-releases/2013/05/16/artificial-forest-for-solar-watersplitting/) or here (Gust, D., Moore, T.A. and Moore, A.L. (2009). Solar fuels via artificial photosynthesis. Acc. Chem. Res. 42:
1890-1898) or here (Concepcion, J.J., House, R.L., Papanikolas, J.M. and Meyer, T.J. (2012). Chemical approaches to artificial photosynthesis. Proc. Natl. Acad. Sci. 109:
15560-15564)].

· Design a system for growing plants in space. What do plants need, and what do they need to avoid / be protected from?

· In what ways might climate change impact plant productivity?