Exam 7: Photosynthesis: Using Light to Make Food

What is responsible for the yellow-orange coloration of leaves in the fall?

What is the function of stomata?

Plants obtain most of their water through their ________.

Plants need carbon, hydrogen, and oxygen atoms to synthesize organic molecules to make new leaves, roots, or stems. Which statement about where they get these atoms is correct?

-Which compound is a direct output of the Calvin cycle?

In photosynthesis, redox reactions ultimately transfer electrons from ________ to ________.

-The last stage of one complete turn of the Calvin cycle involves regeneration of ________.

What are the membranous sacs found within a chloroplast?

A plant that was grown in the dark continuously would ________.

The energy of wavelengths that appear ________ is LEAST useful to photosynthesis.

All but one of these is an advantage of biofuels from food crops. Choose the EXCEPTION.

A discrete packet of light is called a ________.

Photosynthesis contributes to plant growth by ________.

What wavelength of light is reflected by a plant that appears blue to us?

A shade-tolerant plant that is provided its preferred wavelength of light, but only minimal amounts of water, would likely experience ________.

The rate of photosynthesis in an aquatic plant can be determined by the number of bubbles released from the plant. These bubbles ________.

The products of the light reactions of photosynthesis are ________.

Interconnected sacs of membranes inside the chloroplasts called ________ are suspended in a thick fluid called the ________.

Scenario You work for a company selling tropical rain forest plants commonly found in the understory of the forest. These plants are shade tolerant and can be grown indoors because they require low light. Your employer wants you to find out what is the best type of light to maximize growth of these understory plants. Using a full spectrum of natural light would cause these plants to die because they are a shade-tolerant plant species. From your biology class, you recall that the light-dependent reactions of photosynthesis involve pigment molecules that absorb light of specific wavelengths. You also remember the experiments done by the German biologist Theodor Engelmann, in which he separated light using a prism into different wavelengths and then determined which wavelengths were best for promoting photosynthesis in the algae species he was examining. Your goal is to determine which wavelengths (colors)of light are best for promoting photosynthesis to enhance growth in your species of plant. To achieve this, you grew your plants under different wavelengths of light and measured their growth rates. The wavelengths were measured in nanometers (nm), and the growth rate was measured in millimeters per day (mm/day). The data you collected are as follows: Make a bar graph plotting growth rates on the y-axis and wavelengths of light on the x-axis. Referring to your graph, answer the following questions: -Which of these wavelengths is LEAST useful to your plants?

-In the accompanying figure, the molecule that makes up the bulk of the mass of the plant comes in mostly ________.