The three types of plant tropisms include gravitropism (response to gravity), phototropism (response to light), and thigmotropism (response to touch).

**Photoperiodism** is the term that describes the response of plants towards the periods of light and darkness. This response is responsible for the time synchronization of plants in seasonal activities like the production of flowers and growth.

**Short-day plants** are plants that require a long period of darkness in their life cycle. These plants only produce flowers when the length of the day is less than 12 hours. Examples of short-day plants are chrysanthemums and poinsettias.

On the other hand, **long-day plants** are plant species that require more hours of exposure to sunlight than in darkness. Plants like spinach and irises are considered as long-day plants because they bloom when days are longer.

Before winter, plants may shed their leaves, slow down their growth process, turn off photosynthetic pathways, transport materials from leaves to roots, seal leaves off from the rest of the plant. This is evident in deciduous plants. If the plants were to keep the leaves during winter, the leaves would also get damaged by frost causing great water loss.

The days become shorter during the onset of winter, during this season auxin production drops while ethylene production increases. This triggers the chemical pathways for chlorophyll to stop and nutrients are transported out of the leaves for storage. The abscission layer of cells is formed at the petiole, which seals the leaf from the rest of the plant, the leaf then falls off

Plants normally need sunlight to grow. However, some plants do well in low-light conditions, while other plants would require more sunlight. To determine the light conditions needed by a particular flowering plant, an experiment must be conducted using the following steps:

1. Prepare three marigold plants in three identical pots. Label each pot with A, B, and C.
2. Place Pot A in a place where it can get a full exposure to sunlight every day.
3. Expose Pot B into the sunlight for 6 hours every day. Once the exposure is done, keep it in a dark room where no light can reach the plant.
4. Expose Pot C into the sunlight for 3 hours every day. Once the exposure is done, keep it in a dark room where no light can reach the plant.
5. In equal amounts, water the plants every day.
6. Observe the potted plants for the next 20 days and record the time when the flowers bloomed for each pot.
7. Determine which flowering plant has bloomed at the fastest time.