As the nights get longer and the temperatures become cooler, some plants

As explained below.

Explanation:

Generally, what is seen as the night gets cooler the temperature drops to point and plant growth and developmental activities stopped even the extreme temperature can have profound impacts on the development of plants, the activity is limited to the time of day and plays then begins to sleep. Foremost plants spring season which is associated with warm climates is suitable for the growth and germination of seeds. Some plants are adapted to the cool and colder weathers like the Lily, Pansies and the Arctic Moss, Arctic Willow are amongst the commonest type. These plants have fewer or fewer leaves and condense into small shapes and hence save energy and later on open and take energy and heat from the sun.

The answer is enter a state of dormancy, or inactivity.

Idont know but good luck; )

Mitochondria produce atp, a high energy compound. atp is used for all sorts of enzyme-mediated reactions, such as making proteins/nucleotides/etc, certain compounds cross the cell membrane, muscles move, etc.  without this source of energy, a cell will die. it will not be able to repair itself, defend against pathogens, etc.