Lesson 2.4 - Comparing Photosynthesis and Cellular Respiration

You have learned about photosynthesis and cellular respiration.  You will revisit these terms and what you have learned using another approach. 

Read Comparing Photosynthesis and Cellular Respiration on page 185.  Then, complete the statements with the correct words.

Question 1. Photosynthesis ____________ energy; cellular respiration _____________ energy.

Question 2. Photosynthesis ____________ oxygen; cellular respiration _____________ oxygen.

Question 3. Photosynthesis ____________ glucose; cellular respiration _____________ glucose.

Question 4. Photosynthesis ____________ carbon dioxide; cellular respiration _____________ carbon dioxide.

Question 5. Photosynthesis ____________ water; cellular respiration _____________ water.

Question 6. Where does most of the photosynthesis in the world occur?

Question 7. What organisms are responsible for most of the photosynthesis in the world?

 

 

Then, return here to continue this lesson.

 

 

 

 

 

 

To learn even more about photosynthesis and cellular respiration, insert your science.connect 1 CD into your computer, and launch the Photosynthesis applet. 

Work through the ten pages of the activity and answer the questions below.

If you don't have the CD refer to the answers to the following questions.

Question 8. What is the source of energy for most living things?

Question 9. What percent of incoming solar energy is converted into chemical energy by plants?

Question 10. What percent of the total carbon dioxide in the atmosphere is converted into carbohydrates by plants?

Question 11. What is the name of the organelle in plant cells where photosynthesis takes place?

Question 12. What are mitochondria often called?

 

Then, return here to continue this lesson.

 

 

 

 

 

 

 

 

 

 

 

 

Answers to Questions:

 

Question 1. Photosynthesis ____________ energy; cellular respiration _____________ energy.

Photosynthesis stores energy; cellular respiration releases energy.

Question 2. Photosynthesis ____________ oxygen; cellular respiration _____________ oxygen.

Photosynthesis produces oxygen; cellular respiration uses oxygen.

Question 3. Photosynthesis ____________ glucose; cellular respiration _____________ glucose.

Photosynthesis produces glucose; cellular respiration uses glucose.

Question 4. Photosynthesis ____________ carbon dioxide; cellular respiration _____________ carbon dioxide.

Photosynthesis uses carbon dioxide; cellular respiration produces carbon dioxide.

Question 5. Photosynthesis ____________ water; cellular respiration _____________ water.

Photosynthesis uses water; cellular respiration produces water.

Question 6. Where does most of the photosynthesis in the world occur?

Most of the photosynthesis in the world occurs in marine habitats, that is, in bodies of water such as oceans and lakes.

Question 7. What organisms are responsible for most of the photosynthesis in the world?

Marine algae are responsible for most of the photosynthesis in the world.

 

Click to return to where you left off in this lesson.

 

 

 

 

 

 

 

 

 

 

 

Answers to Questions:

Question 8.What is the source of energy for most living things?

The sun is the source of energy for most living things.  You might want to research the sources of energy for those living things that do not use the sun.

Question 9. What percent of incoming solar energy is converted into chemical energy by plants?

According to the information, 1 to 2 percent of incoming solar energy is converted into chemical energy by plants.  This is actually a high estimate.  A grain field might capture that much, but forests convert only 0.5 to 1.5% of the incoming solar radiation into chemical energy.  This is because only 44% of the incoming solar radiation is of the kind that plants can use, and of that fraction only a small percentage is captured. 

Earth has large areas where very little photosynthesis occurs.  Deserts, deep oceans, cities, highways, and the Arctic and Antarctic regions are some of the areas with little photosynthesis.  The average percent of solar energy converted to chemical energy over the entire Earth is much less than 1%.  Some texts say that it is as little as 0.025%. 

Question 10. What percent of the total carbon dioxide in the atmosphere is converted into carbohydrates by plants?

Over 10% of the total carbon dioxide in the atmosphere is converted into carbohydrates by plants each year.

Question 11. What is the name of the organelle in plant cells where photosynthesis takes place?

Photosynthesis takes place in the organelle called the chloroplast.

Question 12. What are mitochondria often called?

Mitochondria are often called the power plant of the cell.

 


Now, do Assignment 9B.  Page forward to access the computer-scored assignment.