Written Assignment 7

WrittenAssignment 7



WrittenAssignment 7


Q1.Epidermal cells play a major role in water conservation movements ofgrasses.

Q2.Cytokinins are groups of chemicals that stimulate cell division.

Q3.Phenylacetic acid (PAA) is an example of an auxin or auxin–like growthregulator.

Q4.Turgor movements can be caused by pulvini.

Q5.The suppression of axillary or lateral bud growth by the terminal budis called apical dominance.

Q6. Light causes auxins to produce a stronger response in plants as aneffect of light on auxins.

Q7. Lactifers cells twist a leaf petiole to keep it oriented towardthe sun throughout the day.

Q8. Trilene is apparently synthesized from carotenoid pigments inplastidsQ9. Acetyl CoA is a precursor to gibberellinsynthesis

Q10.A precursor is a simple molecule that produces a new molecule afterreacting with another molecule

B.True/False Questions

Q12.Florigen has not yet been proved to exist, and the theory thatflowering hormones exist has been discarded. True

Q13.An etiolated plant is spindly and pale. TrueQ14. Phototropicresponses can vary according to light intensity. TrueQ15.In dryweather, increased turgor causes grass leaves to roll up. True

Q16.Day–neutral plants do not need a specific period of light toflower. FalseQ17. The coiling of plant tendrils and the twiningof climbing plant stems are examples of gravitropism. FalseQ18.Abscisic acid promotes senescence. TrueQ19. A taxis is amovement usually found in flowering plants. TrueQ20. Ethylenegas is used to ripen bananas for the supermarket. TrueQ21.Herbaceous dicots are the least sensitive to auxins. True

.Discussion Questions

Q22.The Darwins` experiment on grass seedlings showed that the tip of thecoleoptile somehow influenced the bending toward light. The Darwinswere not sure whether the influence was chemical, electrical, orsomething else. How did Went`s experiment show that the influence waschemical?

Went’sexperiment proved a chemical change through the ireversable changesof the grass seedlings. The grass seedlings illustrated an effect ofa regulation in the absolute energy consumption. Went’s experimentshowed the difference in water exchange in the grass seedlings andthe resultant effect on gaseous exchange. Went’s experimentjustifies that plants respond different towards various lightintensities. This experiment explains the chemical change throughclose observations on coleoptile and the plant hormone behavior.

Q23.Explain the difference between climacteric and nonclimacteric fruitand discuss the commercial value of knowing the difference.

Aclimacteric fruit requires the ethylene for the process of ripeningwhile the nonclimacteric fruit ripens without the ethylene. Aclimacteric fruit example is the mango that requires the ethylene forthe ripening process. An orange is an example of a nonclimactericfruit since the orange ripens without the use of the ethylene. Thecommercial value of understanding the difference translates to largescale farming for timely profits.

Q24.Explain the difference between dormancy and quiescence and describetwo methods of artificially breaking dormancy in some seeds

Dormancyis a condition where the seed fails to germinate due to prevailingcondition. Dormancy is defined as a condition where the seed cannotgerminate until exposed to special events or triggered conditions.The conditions originate from effects from the absicsic acid restinga plant phase.Quiescence is a state where the seed is in a suspendedgrowth or development. During the quiescence, the seed may resumegrowth upon allocation of favorable growth conditions such as oxygen.In quiescence, the embryo is in a state of resting which isreversible upon provision of favorable conditions.Artificial methodsof breaking seed dormancy include scarification which entailsweakening the seed coat through chemicaltreatments. Other methodsinclude exposing the dormant seeds to the light through airing onrooftops or other open place in the sun.

Q25You want to enjoy your lettuce crop as long as possible. How wouldyou prevent it from bolting?

Plantinglettuce in shaded areas of the given garden help prevent the boltingresulting in successful harvests. The process entails soaking thelettuce before planting, planting behind tall plants in the gardenand providing sufficient water capacities during the hot weather. Theplanting soil should be moist before planting to avoid the lettucebolting. An extended procedure should include covering the lettucesoils with a layer of damp soil. This waters the lettuce regularlyover the hot season or period. Lettuce should be grown in the housewhere the light conditions can be regulated. This procedure requirestimely exposure of the lettuce to sun with raw covers as extraprovisions.

26.Discussthe ecological advantages of dormancy and quiescence to a plant. Anext germination process requires a dry condition to influence apositive ecological difference based on imbibition process.Advantageous processes revolve around complete embryonic procedure tocontribute to the general seed structure and formation. Seedlingestablishment is a defined advantage originating from completegermination.

Designan experiment to prove or disprove that plants react to soothingmusic. (Review experimental design study notes from unit 1.)

Acontrol experiment involves observational procedure of stimulireaction based on various environmental conditions ranging frommusical and heat earth reciprocatesmeasures. Resultant effectsformulate from common stimuli of a general germination process