Chapter 2, Problem 1RQ

Summary Introduction

Introduction: Human disease occurs due to an interaction of the host, the agent, and the environment. The host must be another human or animal; the agent must be bacteria, virus, or other microorganism, and the environment (may be the pollutant). There are some diseases that are linked with genes.

Answer to Problem 1RQ

Correct answer: “Endemic means that a disease is habitually present in human population”. Hence, option b. is the correct answer.

Explanation of Solution

Reason for the correct answer:

Option b. is given as “Is habitually present in human population”.

The habitual occurrence of a disease within a particular geographical area is called as an endemic. Endemic refers to a specific disease in the human population that usually occurs in a specific area without any external inputs.

Hence, the correct answer is option b.

Reasons for incorrect answers:

Option a. is given as “Occurs clearly in excess of normal expectancy”. Outbreak means a disease that occurs clearly in excess of normal expectancy. Hence, option a. is incorrect.

Option c. is given as “Affects a large number of countries simultaneously”. Pandemic means a disease affects a large number of countries simultaneously. Hence, option c. is incorrect.

Option d. is given as “Exhibits a seasonal pattern”. Epidemic means a disease that exhibits a seasonal pattern. Hence, option d. is incorrect.

Option e. is given as “Is prevalent among animals”. Zoonoses mean a disease is prevalent among animals. Hence, option e. is incorrect.

Hence, options a., c., d., and e. are incorrect.

Conclusion

Endemic explains that a disease is habitually present in human population.