Question

Explain how distribution of animals and plants is affected by light, with examples.

Hint:

Plants depend on light for photosynthesis and flowering (photoperiodism), while animals rely on light for migration, reproduction, and daily activity cycles.

Answer 1

Effect of Light on Plants: - Light is one of the most important abiotic factors influencing plant distribution. - Plants show responses to both intensity and duration of light (photoperiodism). \[\begin{array}{rl} \bullet & \text{High light intensity favors growth of sun-loving plants (heliophytes) such as sunflower.} \\ \bullet & \text{Shade-loving plants (sciophytes) like ferns thrive in low light intensity.} \\ \bullet & \text{Flowering in plants like wheat and rice depends on day length (short-day and long-day plants).} \\ \end{array}\] Effect of Light on Animals: - Many animal activities like migration, reproduction, feeding, and diurnal rhythms are controlled by light. \[\begin{array}{rl} \bullet & \text{Birds such as migratory geese and Siberian cranes use changes in day length as cues for migration.} \\ \bullet & \text{Reproduction in many animals is photoperiod-dependent (e.g., sheep breed in short-day conditions).} \\ \bullet & \text{Nocturnal animals like owls and bats are active in darkness and rest during the day.} \\ \end{array}\] Conclusion: Light governs photosynthesis in plants and influences behavior, physiology, and distribution of animals. Thus, it plays a central role in shaping ecosystems.