Ethephon
(1) Thinning Cotton, Cherry and Walnut
(2) Promotes female flowers in cucumber
(3) Hastens the fruit ripening in tomatoes and apples
(4) All of these
Abscisic Acid
Which of the following is not correct?
(1) Acts as general plant growth inhibitor and an inhibitor of plant metabolism
(2) Inhibits seed germination
(3) Stimulates the opening of stomata in the epidermis
(4) Increases the tolerance of plants to various kinds of stresses
Which of the following is a stress hormone in plants?
(1) ABA
(2) GA3
(3) Cytokinin
(4) Auxins
ABA plays an important role in except
(1) Seed development
(2) Maturation and dormancy
(3) Helps seeds to withstand desiccation and other factors unfavorable for growth
(4) Antagonist to Cytokinin
More than one PGR are not involved in which of the following physiological effect?
(1) Dormancy in seeds or buds
(2) Abscission, Apical Dominance
(3) Senescence
(4) Fruit Ripening
Which of the following statements is not correct?
(1) PGR is of only one kind of intrinsic control
(2) Only under genomic control, these PGRs play an important role in plant growth and development
(3) Many of the extrinsic factors such as temperature and light control plant growth and development via PGR
(4) Vernalization, Flowering, dormancy, seed germination and plant movements are under the control of extrinsic factors along with intrinsic factors
For the induction of flowering, some plants require a
(1) Periodic exposure to light
(2) Continuous exposure to light
(3) No exposure to light
(4) No exposure to night
If a plant needs exposure of light more than a defined period for flowering, such plant is called
(1) Long day plants
(2) Short day plants
(3) Day neutral plants
(4) Red light plants
Which of the following is not true for flowering?
(1) Only duration of dark period is important
(2) Certain plants depend not only on a combination of light and dark exposures but also their relative durations
(3) The site of perception for light or dark duration are the leaves
(4) There is a hormonal substance which migrates from leaves to shoot apices for inducing flowering only when the plants are exposed to the necessary inductive photoperiod.
Flowering can be affected in certain plants
(1) by quantitative exposure to low temperature
(2) by qualitative exposure to low temperature
(3) Both A and B
(4) It does not depend on low temperature exposure