Practice important
Premature fruit-drop prevention
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. A grower wants to reduce premature fruit drop caused by weakening of the fruit stalk before harvest. Which auxin-based treatment is most appropriate?
A.
A dilute auxin spray applied before the abscission zone becomes fully active
B.
A concentrated auxin spray applied only after the fruits have detached
C.
An auxin inhibitor applied during early fruit development
D.
A cytokinin antagonist applied immediately before harvest
Correct Answer:
A dilute auxin spray applied before the abscission zone becomes fully active
Explanation:
Auxin can delay fruit abscission when applied before the separation layer becomes fully functional. Once fruits have detached, an auxin spray cannot restore their attachment.
2. The principal basis for using auxin to prevent premature fruit drop is that auxin treatment can:
A.
Maintain the physiological connection between the fruit and its supporting tissue
B.
Convert all mature fruits into seedless fruits
C.
Stop fruit respiration permanently until harvest
D.
Replace the vascular tissue of a detached fruit stalk
Correct Answer:
Maintain the physiological connection between the fruit and its supporting tissue
Explanation:
Auxin delays the development and activation of the abscission zone, helping maintain fruit attachment and thereby reducing premature fruit drop.
3. A fruit crop shows increased ethylene production during stress, followed by early activation of the abscission zone. Which auxin response would most directly help prevent the resulting fruit drop?
A.
Applying an effective dilute auxin treatment before extensive abscission-zone separation occurs
B.
Applying a high auxin concentration after the fruit has fallen
C.
Removing auxin from the fruit stalk to accelerate ripening
D.
Applying auxin only to soil after all fruits have reached maturity
Correct Answer:
Applying an effective dilute auxin treatment before extensive abscission-zone separation occurs
Explanation:
Auxin application before separation is advanced can delay abscission and help counter the tendency toward premature fruit drop associated with stress-related abscission.
4. Why is the timing of an auxin spray critical when the objective is to prevent premature fruit drop?
A.
Auxin is most useful while the fruit remains attached and the abscission process is still reversible or delayable
B.
Auxin acts only after the fruit has completely dried on the ground
C.
Auxin prevents fruit drop only by increasing seed germination after harvest
D.
Auxin becomes active only when the fruit has lost all connection with the parent plant
Correct Answer:
Auxin is most useful while the fruit remains attached and the abscission process is still reversible or delayable
Explanation:
Preventive auxin treatment must precede complete separation because its role is to delay abscission while the fruit is still physiologically connected to the plant.
5. A farmer doubles the recommended auxin concentration to obtain stronger protection against premature fruit drop. Which conclusion is most scientifically appropriate?
A.
The higher concentration may cause undesirable effects, so an effective dilute concentration should be used
B.
Any increase in auxin concentration always produces proportionally better fruit retention
C.
A higher concentration guarantees that mature fruits will never detach
D.
Auxin concentration has no influence on the response of fruit tissues
Correct Answer:
The higher concentration may cause undesirable effects, so an effective dilute concentration should be used
Explanation:
Auxin responses are concentration-dependent. Excessive amounts may produce abnormal growth or other injury, so fruit-drop prevention requires an appropriate dilute dose rather than indiscriminate overapplication.
6. In an experiment, identical fruit-bearing branches receive different treatments before the usual period of fruit drop. Which result best demonstrates successful auxin-mediated prevention of premature fruit drop?
A.
A greater percentage of treated fruits remains attached without abnormal injury compared with untreated branches
B.
Treated fruits detach earlier but become greener after falling
C.
Treated branches lose all leaves while fruit number remains unmeasured
D.
Treated fruits show only increased seed germination after removal from the plant
Correct Answer:
A greater percentage of treated fruits remains attached without abnormal injury compared with untreated branches
Explanation:
The relevant measure of success is increased retention of healthy fruits during the period when untreated fruits normally undergo premature abscission.
7. Which treatment design would provide the strongest evidence that auxin, rather than differences in environmental conditions, prevented premature fruit drop?
A.
Compare matched branches under the same conditions, with one receiving the auxin spray and the other receiving only the spray solvent
B.
Compare an auxin-treated orchard in shade with an untreated orchard in full sunlight
C.
Apply different auxin concentrations to unrelated species and compare their total yields
D.
Treat only fruits that have already fallen and record their color after one week
Correct Answer:
Compare matched branches under the same conditions, with one receiving the auxin spray and the other receiving only the spray solvent
Explanation:
A matched untreated control receiving the solvent isolates the effect of auxin and allows fruit retention to be compared under otherwise similar conditions.
8. Which observation would indicate that an auxin treatment was applied too late to prevent a particular fruit from dropping?
A.
The fruit had already separated from the plant when the spray was applied
B.
The fruit remained attached during the normal early-drop period
C.
The abscission zone had not yet begun visible separation when treatment occurred
D.
The treated fruit retained a healthy stalk connection until harvest
Correct Answer:
The fruit had already separated from the plant when the spray was applied
Explanation:
Auxin can delay abscission only while the fruit is attached and the separation process has not been completed; it cannot reattach a fruit that has already fallen.
9. A researcher removes the fruit from the plant immediately after applying auxin and then reports that auxin failed to prevent premature fruit drop. What is the major flaw in this conclusion?
A.
Fruit retention can be assessed only while the fruit remains attached to the plant
B.
Auxin prevents fruit drop only by increasing fruit color after detachment
C.
Detached fruits are the ideal system for measuring abscission prevention
D.
Auxin can prevent detachment even when the fruit is no longer connected to the plant
Correct Answer:
Fruit retention can be assessed only while the fruit remains attached to the plant
Explanation:
The preventive effect concerns delaying abscission at the fruit–plant connection. Removing the fruit eliminates the structure in which auxin-mediated retention can be observed.
10. Two orchards receive auxin before the expected fruit-drop period. Orchard X has a moderate reduction in fruit drop, whereas Orchard Y shows little response. Which explanation is most consistent with auxin-based fruit-drop prevention?
A.
The treatments may have differed in timing, dose, tissue responsiveness, or the stage of abscission
B.
Auxin must produce the same response in every crop regardless of dose or developmental stage
C.
The absence of complete protection proves that auxin has no role in fruit retention
D.
Auxin prevents fruit drop only when applied after the abscission zone has fully separated
Correct Answer:
The treatments may have differed in timing, dose, tissue responsiveness, or the stage of abscission
Explanation:
Auxin-mediated prevention depends on appropriate concentration, application timing, and responsiveness of the fruit and abscission tissues; therefore, responses can vary between orchards.
Short Questions and Answers
Practice short questions and answers related to
Premature fruit-drop prevention
.
Short questions are currently unavailable for this page.