Introduction:
The plant and animal kingdoms play a crucial role in shaping the environment and sustaining life on Earth. Together, they contribute to the formation and maintenance of the biosphere, which encompasses all living organisms and their interactions with the physical environment.

Explanation:
Biosphere:
The biosphere refers to the zone of the Earth where life exists. It includes all ecosystems, from the depths of the oceans to the highest mountains, where plant and animal life can be found. The biosphere is a dynamic and interconnected system where plants and animals interact with each other and with the non-living components of the environment.

Plant Kingdom:
Plants are the primary producers in the biosphere. They convert sunlight, water, and carbon dioxide into glucose through the process of photosynthesis. This glucose serves as a source of energy for plants and forms the basis of the food chain. Plants also release oxygen as a byproduct of photosynthesis, which is essential for the survival of animals and other organisms.

Plants play a crucial role in nutrient cycling and maintaining the balance of gases in the atmosphere. They absorb carbon dioxide from the atmosphere and release oxygen, helping to regulate the composition of the air we breathe. Additionally, plants take up nutrients from the soil, which are then transferred to animals through the consumption of plant material.

Animal Kingdom:
Animals are consumers in the biosphere, relying on plants and other animals for their energy and nutrient requirements. They play various roles in ecosystems, including herbivores (plant eaters), carnivores (meat eaters), and omnivores (eating both plants and animals). Animals contribute to the diversity and complexity of ecosystems through their interactions with other organisms.

Animals also play a crucial role in nutrient cycling. They consume plant material and other animals, breaking down organic matter and releasing nutrients back into the environment through their waste. This recycling of nutrients is essential for the growth and survival of plants and other organisms.

Conclusion:
In conclusion, the plant and animal kingdom together contribute to the formation and maintenance of the biosphere. Plants provide the foundation of the food chain, release oxygen, and regulate the composition of the atmosphere. Animals, on the other hand, consume plants and other animals, contributing to nutrient cycling and ecosystem dynamics. The biosphere, encompassing all living organisms and their interactions, is a result of the combined efforts of the plant and animal kingdoms.