Define each of the following terms and explain how each of them can benefit the plant.
a. gravitropism
b. phototropism
c. thigmotropism
d. photoperiod

definition with benefit is given below of

1st. gravitropism

2nd. phototropism

3rd. thigmotropism

4th. photoperiod

Explanation:

1st is gravitropism

gravitropism is process in which plant grow in the direction that gravity act

It is also called geotropism

and

Gravitropism is important for plants because it directs the roots to grow in the downward direction that is important for obtaining nutrients

2nd is phototropism

phototropism  is the process in which plant growth directed by the light

and

we know plants need light to carry out photosynthesis

so  Phototropism direct the growth of the stem and branch toward sunlight

3rd is thigmotropism

thigmotropism is the directional change in growth of plant in response to a touch stimulus

and

thigmotropism is especially important for climbing plant that is use support to climb up

4th is photoperiod

photoperiod is the physiological change in organism in the response to length of the day and night

and

it play important role to determining the physiological developmental process in the plant such as budding and tuberization

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.