Fill in each blank with the correct word from the lesson.

1. Human _______ is controlled by the diaphragm — a dome-shaped muscle below the lungs.
2. _______ use different breathing organs: fish use gills, insects use spiracles and tracheae, frogs use skin and lungs, birds use lungs with air sacs, and mammals use lungs.
3. Fish use gills to extract dissolved _______ from water.
4. As water flows over the gill plates, oxygen dissolved in the water diffuses into the blood and _______ diffuses out.
5. Insects breathe through small pores called spiracles connected to a network of tubes called tracheae that deliver air directly to _______s.

Choose the best option for each question.

1. How do fish breathe?
   a) Through lungs like mammalsb) Through spiracles on their bodyc) Through gills that extract oxygen from waterd) Through skin only
2. What is the role of the diaphragm in breathing?
   a) Filtering dust from airb) Pumping bloodc) A muscle that changes chest volume to move air in and outd) Producing oxygen
3. What are alveoli?
   a) Blood vessels in the heartb) Tiny air sacs in the lungs for gas exchangec) Air holes in insect bodiesd) Gill plates in fish

Write T for True or F for False in the brackets.

1. Through gills that extract oxygen from water is one of the key concepts in the lesson on Breathing in Animals.
2. Through lungs like mammals is the main topic of this lesson.
3. A muscle that changes chest volume to move air in and out is one of the key concepts in the lesson on Breathing in Animals.
4. Filtering dust from air is the main topic of this lesson.

1. In your own words, explain what Breathing in Animals means.
2. List two things you learned from this lesson on Breathing in Animals.