PLEASE USE YOUR OWN WORDS TO ANSWER THESE 1 What has been th

PLEASE USE YOUR OWN WORDS TO ANSWER THESE:

(1) What has been the relationship between atmospheric CO₂ levels and stomatal densities? Where does the evidence for this relationship come from?

(2) Will a further doubling of anthropogenic CO₂ levels ultimately lead to a complete loss of stomata? Explain.

(3) What is the function of the HIC gene in Arabidopsis?

(4) Without a functional HIC gene, what would be the result of a doubling of CO₂ levels?

USE YOUR OWN WORDS!

response sources that couldbcused in experiments to w-wah,,·AmLew sa,am-3062 awn quantum lasers could find eventual applica- acid sequence ofthenormal and mutant HIC sions might not drastically alter stomatal .ha. Wpadlkm. Een \'s.1-1selin ments show that roughly doubling the cr ponent or components of the waxy cuticle then the \'spare\' heat from the human body e R. be te ast d atide Mantle recycled in Sardinia Coping with human CO2 emissions Barry B. Hanan concentration. The implication is tat thethat the stomatal index is increased? Gray e Laura Serma and Carmen Fenall For two centuries, a natural eeriment has been showing how ncreasng atmospheric Co, affeats plants Laboratory work provides pointers as to 0 ocean crust is especially thick-30 km up to 10% of the ocean floor, have a similar mutant plants, and this might be sufficient their comparative buoyancy and to accrete to one another. As the authors point out, if this issue, however, Gasperiniet al propose tributetothe sources ofocean basaks\"Three the radiogenic isotope signatures of hotspot 00, hic) Both mutants have higher stomatal indices celand and Haveaii) both form from plumes chemistry of the Logudoro lavas resembles cuticle and the development of stomata. (100 km wide) of hot upwelling deep mantle chemistryis consistent not only with contri- important in processes involving cell-cell early stageofplume development,producing lithosphere from beneath the continents processes-providing an adequate environ over more mature plumes, after dispersion of beneaththecontinents\', there is the question atmospheric CO, enrichment. This finding Figure I Plant stomata and anthropogenic carbon dioxide ensissions, Over the past 200 years, the not only provides new evidence linking CO, number of plant stomata (each of which consists ofa pair ofguardcells, delimiting a pore forgas and stomatal development, but also opens exchange) has decreased in response to increasing CO, kvlsThistrend may not continue in the respoese to CO, concentrations doublethos of today, but increases in plants witha rautant HIC gme. The authors suggest that the neemal HIC gene negatively regalates stematal development at cope with anthropogenic CO, emissions in An inverse relationship between stomatal the higher CO, cencentrations, as shown here, a. The nermal HIC gene may encode an enryme density and atmospheric CO, levels, fom involved in the synthesis of very-long-chain fatty acids, deposited at the surfaor ofthe guand lls pre-industrial to modern times, has been These fatty acids might be needod for the ditfusion ofa molecule-stimulated by high CO, demonstrated by analyses of specimens col- concentrations-that can reach neighbouring epidermal cells and repress their ability to develop is that plants seem to be well armed to cope mantle decompresses and melts. This crust, theoriginal plume source.Solving this enig repressor Laboratory experiments in which plants is therefore impaired, so it can not reach all its target cells, which develop into stomata

Solution

1.What has been the relationship between atmospheric CO2 levels and stomatal densities? Where does the evidence for this relationship come from?

2.

3.

4.