Question

quiz
1 which sentence from the article supports the main idea of the article?
(a) scientists can measure a plant’s rate of photosynthesis.
(b) too much light will eventually kill the plant.
(c) another factor that affects the rate of photosynthesis is temperature.
(d) an enzyme is a protein that speeds up the rate of a reaction.
2 read the following paragraph from the article.
lets look at how a sunflower uses photosynthesis to make food. it needs three ingredients: carbon dioxide (co₂), water (h₂o) and sunlight. the plant then turns the ingredients into the sugar glucose (c₆h₁₂o₆) and oxygen (o₂). it does this through chemical reactions. a chemical reaction is a process by which chemicals change from one substance into another.
which statement summarizes the paragraph?
(a) sunflowers turn carbon dioxide, water and sunlight into sugar and oxygen through photosynthesis.
(b) photosynthesis is a chemical reaction used by sunflowers and many other types of plants.
(c) most types of plants need oxygen and the sugar glucose in order to survive in their environments.
(d) there are three main ingredients sunflowers need to produce oxygen in a chemical reaction.
3 use the images and information from the article to select the true statement.
(a) plants will continue to grow bigger when the light intensity in their environment increases.
(b) plants grow best at certain temperatures, light intensities, and levels of carbon dioxide.
(c) plants need more carbon dioxide than water to increase the rate of photosynthesis.
(d) plants that make oxygen are more likely to survive than plants that make glucose.
4 read the following selection from the article.
when carbon dioxide increases in the greenhouse, so does the sunflower’s rate of photosynthesis. it is able to make food more quickly. however, at a certain point, adding more carbon dioxide will no longer affect the sunflower. the rate of the reaction plateaus. no matter how much carbon dioxide is present, the plant can only make so much glucose.
how does image 3 support the information in the selection?
(a) it illustrates the main reason carbon dioxide can only be added to greenhouses with machines.
(b) it explains how carbon dioxide is more important to photosynthesis than temperature in sunflowers.
(c) it highlights the difference between the effects of light intensity and carbon dioxide on photosynthesis.
(d) it shows carbon dioxide does not affect the rate of photosynthesis after a certain point.

Explanation:

Question 1

To determine which sentence supports the main idea about photosynthesis (implied by the options related to factors affecting it), we analyze each option:

• Option A: Measuring photosynthesis rate is a detail, not the main idea's support.
• Option B: Light's effect on plants is a side point, not core to photosynthesis factors.
• Option C: Temperature affecting photosynthesis rate is a key factor, likely supporting the main idea about factors influencing photosynthesis.
• Option D: Enzyme definition is unrelated to the main idea of photosynthesis factors.

The paragraph describes sunflower photosynthesis: ingredients (CO₂, H₂O, sunlight) → products (glucose, O₂) via chemical reactions.

• Option A: Matches the summary (ingredients, process, products).
• Option B: The paragraph focuses on sunflowers, not "many other plants".
• Option C: The paragraph is about photosynthesis, not plant survival needs.
• Option D: Focuses on oxygen production, but the paragraph is about making food (glucose) and oxygen.

Analyzing statements about plant growth/photosynthesis factors:

• Option A: Plants don't grow infinitely with light (e.g., saturation), so false.
• Option B: Plants have optimal conditions (temp, light, CO₂) for growth, which is true.
• Option C: No comparison of CO₂ and water needs in the article.
• Option D: The article doesn't compare survival of oxygen vs glucose - making plants.

Answer:

C. Another factor that affects the rate of photosynthesis is temperature.

Question 2