Gibberellins Questions in English

(B) Gibberellins are a group of plant growth regulators that play a crucial role in seed germination and breaking dormancy.
Specifically,$GA_3$ (Gibberellic acid) is widely used to break the dormancy of various seeds,including peanut seeds,and to induce sprouting in potato tubers.
They counteract the effects of Abscisic acid $(ABA)$,which is the primary hormone responsible for maintaining seed dormancy.

(D) Parthenocarpy is the development of fruit without fertilization of the ovary.
Since fertilization does not occur,the ovules do not develop into seeds,making these fruits seedless.
$A$: Parthenocarpic fruits are preferred because they are seedless,which is convenient for consumption.
$B$: Gibberellins are plant hormones that can artificially induce parthenocarpy in many species.
$C$: By definition,parthenocarpic fruits are seedless.
$D$: This statement is incorrect because parthenocarpic fruits develop from an unfertilized ovary,not a fertilized one.

(C) Gibberellins are a group of plant growth regulators that promote cell elongation and division.
In viticulture,$GA_3$ (a type of Gibberellin) is specifically applied to grapevines to increase the size of the individual berries and to elongate the fruit stalks,which results in larger bunches and improved fruit quality.

(C) Gibberellins are a group of plant growth regulators that are widely used in agriculture.
One of their primary commercial applications is in the viticulture industry,where they are used to increase the length of the grape stalks and the overall size of the grape fruits.
By promoting cell elongation and division,Gibberellins (specifically $GA_3$) help in improving the quality and yield of grapes.
Therefore,the correct option is $C$.

(A) Bolting refers to the internode elongation just prior to flowering in plants that exhibit a rosette habit,such as beet,cabbage,and many rosette-type plants.
Gibberellins $(GA)$ are plant hormones that play a crucial role in promoting this internode elongation.
By inducing rapid stem growth,$GA$ helps the plant transition from the vegetative rosette stage to the reproductive flowering stage.
Therefore,the correct option is $A$.

(D) Gibberellins are plant hormones that play a crucial role in seed germination.
In cereal seeds like barley and wheat,the embryo releases gibberellins upon imbibition.
These gibberellins diffuse to the aleurone layer,where they stimulate the synthesis of hydrolytic enzymes,particularly $\alpha$-amylase.
This enzyme breaks down the stored starch in the endosperm into simple sugars,which provide the energy required for the growth of the embryo during germination.

(B) Gibberellins stimulate the synthesis of the enzyme $\alpha$-amylase in the aleurone layer of cereal seeds like wheat and barley. This enzyme breaks down stored starch into simple sugars like glucose,which provides the energy required for embryo growth and seed germination.

(D) Gibberellins are plant hormones that play a crucial role in various developmental processes,including seed germination and stem elongation.
One of the primary mechanisms by which $Gibberellins$ $(GA)$ promote growth is by stimulating the synthesis of specific enzymes,such as $\alpha$-amylase,in the aleurone layer of cereal seeds.
This process involves the induction of $RNA$ synthesis (transcription) and subsequent protein synthesis,which are essential for the mobilization of stored nutrients.
Therefore,$Gibberellins$ are known to induce $RNA$ synthesis.

(A) The $bakane$ disease (foolish seedling disease) of rice plants was discovered to be caused by the fungus $Gibberella$ $fujikuroi$.
$E$. Kurosawa reported the appearance of symptoms of the disease in uninfected rice seedlings when they were treated with sterile filtrates of the fungus.
The active substance responsible for this effect was later identified and named $Gibberellin$.

(D) Gibberellins are plant hormones that promote bolting,which is the internode elongation just prior to flowering in plants like beet and cabbage that exhibit a rosette habit.

(A) Gibberellins are plant hormones that regulate various developmental processes,including stem elongation,germination,dormancy,flowering,and sex expression. In certain plants,such as cucumber ($Cucumis$ $sativus$),the application of $Gibberellins$ $(GA)$ promotes the formation of male flowers on female plants. This is a classic example of hormonal control over sex expression in plants.

(A) Gibberellins are a group of plant hormones that promote cell elongation and cell division.
In leafy vegetables,gibberellins are specifically used to increase the size of leaves and stems,thereby enhancing the overall biomass and yield.
They stimulate the expansion of leaves by increasing the cell wall plasticity and promoting cell enlargement.
Therefore,gibberellins are the primary choice for promoting leaf expansion in agricultural practices.

(B) Gibberellins are phytohormones that promote seed germination in cereals by inducing the synthesis of hydrolytic enzymes,such as $\alpha$-amylase,in the aleurone layer.
These enzymes break down stored starch into simple sugars,which provide energy for the growing embryo.
Abscisic acid $(ABA)$ acts as a growth inhibitor and promotes seed dormancy.
Auxins and Cytokinins are involved in cell elongation and cell division,respectively,but they are not the primary hormones responsible for the induction of amylase synthesis during germination.

(D) Gibberellins were first discovered by $E$. Kurosawa in $1926$ from the fungus $Gibberella$ $fujikuroi$, which causes the 'bakanae' (foolish seedling) disease in rice plants. The scientist observed that the fungus secreted a substance that caused excessive elongation of the rice stems.

(B) $GA$.
The rosette habit of cabbage is characterized by short internodes and a cluster of leaves.
The application of gibberellins $(GA)$ promotes internode elongation,which causes the stem to grow longer and changes the rosette growth form into an elongated habit.
This process is known as bolting.

(D) The correct answer is $D$.
Gibberellins promote bolting,which refers to the internode elongation just prior to flowering in plants with a rosette habit (e.g.,beet,cabbage).