Question

1. what is the main purpose of photosynthesis?

a. to make sunlight
b. to make food (sugar) for the plant
c. to make oxygen for humans
d. to absorb water from the soil

1. what gas do plants take in during photosynthesis?

a. oxygen
b. carbon dioxide
c. nitrogen
d. hydrogen

1. what gas do plants release during photosynthesis?

a. oxygen
b. carbon dioxide
c. helium
d. methane

Explanation:

1. Photosynthesis is the process by which plants use sunlight, carbon dioxide, and water to produce glucose (sugar) which is their food. Sunlight is used as an energy source (not made), oxygen is a by - product (not the main purpose for the plant itself), and water absorption is part of the raw materials but not the main purpose.
2. During photosynthesis, plants take in carbon dioxide. Oxygen is released (not taken in), nitrogen is mainly taken in as nitrates from the soil for other metabolic processes (not in the form of nitrogen gas for photosynthesis), and hydrogen is part of water but not taken in as hydrogen gas.
3. As a result of photosynthesis, oxygen is released. Carbon dioxide is taken in, helium is not involved in photosynthesis, and methane is not a product of photosynthesis in plants.

Answer:

1. B. To make food (sugar) for the plant
2. B. Carbon dioxide
3. A. Oxygen