Chapter 36, Problem 1SA

Flatworms digest food ___________

a. inside their cells	c. in a gastrovascular cavity
b. in a gizzard	d. in a complete digestive tract

Summary Introduction

Introduction:

Digestion and absorption are the primary phenomena that take place in the body after the ingestion of food. Majority of the digestion is accompanied with the help of enzymes and acidic environment which is provided in the stomach and intestine.

Answer to Problem 1SA

Correct answer:

Flatworms digest food inside their cells. Hence, the correct answer is option a.

Explanation of Solution

Reason for correct answer:

Option a. is given as “inside their cells.”

Flatworms are parasites, living in the human digestive system. They absorb the digested food from the gut. Flatworms do not need to break the food as it is digested by the digestive system of the host. So, they only need to absorb the nutrients from the gut of the host.

Reason for incorrect answer:

Option b. is given as, “in gizzard.”

The gizzard is present in the avian digestive system. It is used to grind the food in the digestive system of birds. Hence, option b. is incorrect.

Option c. is given as, “In gastrovascular cavity.”

The gastrovascular cavity is present in higher species. Flatworms belong to the family of Platyhelminthes, which do not have well developed digestive system. Hence, option c. is incorrect.

Option d. is given as, “in a complete digestive tract.”

The digestive tract is present in higher species. Flatworms belong to the family of Platyhelminthes, which do not have well developed digestive system. Hence, option d. is incorrect.

Hence, the options b., c., and d. are incorrect.

Conclusion

Flatworms are able to digest the food inside their cells in the absence of a well developed digestive system. Thus, the correct option is a.