Thigmotropism is best observed in

Plant hormones are usually:

The process of soaking rice in water to induce germination is known as $..........$.

Plants are killed in winter by frost because:

What would be expected to happen if:
$(a)$ $GA_{3}$ is applied to rice seedlings
$(b)$ Dividing cells stop differentiating
$(c)$ $A$ rotten fruit gets mixed with unripe fruits
$(d)$ You forget to add cytokinin to the culture medium.

Which of the following exhibits a non-polar movement?