Question

In daytime, most plants lose ______ and take up ______ a. water; carbon dioxide b water; oxygen c. oxygen; water d. carbon dioxide; water

Short answer

a. water; carbon dioxide

Step-by-step solution

Understanding Plant Processes

Plants engage in a process called photosynthesis during the day, where they absorb sunlight to convert carbon dioxide and water into glucose and oxygen. The opposite process, respiration, happens simultaneously, consuming oxygen and releasing carbon dioxide. Moreover, plants lose water through a process called transpiration.

Identifying the Correct Elements

Given the processes of transpiration and photosynthesis, plants lose water through transpiration and take up carbon dioxide for photosynthesis during the day.

Matching with Options

Now, compare the identified elements with the given choices. The correct pair is 'water; carbon dioxide' which matches option (a).

Verification

Verify if the identified option aligns with known plant biological processes: During daylight, plants primarily engage in photosynthesis, which necessitates water loss via transpiration and carbon dioxide uptake for food synthesis. This confirms that the answer aligns with option (a).

Key concepts

Transpiration

Transpiration is a crucial process in plants, involving the movement of water from the roots to other parts of the plant. This process occurs mainly through small openings on the leaves called stomata. Transpiration helps in cooling the plant and also aids in the transport of essential minerals from the soil. Additionally, it creates a negative pressure in the plant, pulling more water and nutrients up from the roots. Here are some key points about transpiration:

• Transpiration occurs primarily during the day when the stomata are open to allow gas exchange needed for photosynthesis.
• It plays a vital role in maintaining the plant's water balance.
• Through this process, plants lose a significant amount of water to the atmosphere.

As a side effect of photosynthesis, transpiration ensures that plants can keep absorbing carbon dioxide while getting rid of excess oxygen.

Plant Respiration

Plant respiration is a metabolic process where plants take in oxygen and release carbon dioxide. This process is essential for converting the energy stored in glucose into usable energy for growth and maintenance. Unlike photosynthesis, respiration occurs in all parts of the plant and during both day and night. Key aspects of plant respiration include:

• It is the reverse of photosynthesis, using oxygen to break down glucose and release carbon dioxide and water.
• This process occurs constantly, even when photosynthesis is not happening.
• It provides the necessary energy for cellular activities required for plant survival.

Understanding plant respiration is crucial, as it highlights the constant balancing act plants perform between absorbing and releasing gases.

Carbon Dioxide Uptake

Carbon dioxide uptake is a vital part of the photosynthesis process in plants. During daylight, plants open their stomata to absorb carbon dioxide from the atmosphere. This carbon dioxide is then used to produce glucose, a form of sugar that provides energy and growth materials. Important details about carbon dioxide uptake:

• It mainly occurs during the day when photosynthesis is active.
• Plants maintain homeostasis by regulating the opening and closing of the stomata.
• Efficient carbon dioxide uptake enhances plant growth and food production.

Through carbon dioxide uptake, plants not only sustain themselves but also help reduce the amount of carbon dioxide in the atmosphere, contributing to the earth's ecological balance.