Plant Tropisms and Photoperiodism

The lecture discusses various types of tropisms in plants, including phototropism, thigmotropism, and gravitropism, which are growth responses to light, touch, and gravity, respectively. It also covers photoperiodism, explaining how plants' flowering is influenced by night length rather than day length, distinguishing between long night and short night plants.

What is the primary factor that influences phototropism in plants?

• Gravity

• Touch

• Water

• Light

Which type of tropism involves plant growth in response to touch?

• Hydrotropism

• Gravitropism

• Thigmotropism

• Phototropism

In gravitropism, how do plants typically orient their growth?

• In response to gravity

• Towards water

• Away from touch

• Towards light

What is the role of gravity in the growth of plants?

• It has no effect on plant growth

• It causes plants to grow towards water

• It influences the direction of root and shoot growth

• It directs growth towards light

Which of the following is NOT a type of tropism discussed in the lecture?

• Hydrotropism

• Gravitropism

• Thigmotropism

• Phototropism

What is the main environmental factor that affects photoperiodism in angiosperms?

• Humidity

• Temperature

• Night length

• Day length

Which type of plant is likely to flower in the fall or winter due to longer nights?

• Long night plants

• Short night plants

• Tropical plants

• Day-neutral plants

What happens to a long night plant if its night is interrupted by light?

• It wilts

• It grows faster

• It does not flower

• It flowers

Which type of plant is likely to flower in the spring or summer due to shorter nights?

• Desert plants

• Short night plants

• Long night plants

• Day-neutral plants

What is the significance of photoperiodism in plants?

• It influences root growth direction

• It helps plants grow towards light

• It determines flowering based on night length

• It allows plants to respond to touch