Exploring Bird Biology and Flight

Which of the following is a characteristic feature of all birds?

• Presence of fur

• Presence of feathers

• External ears

• Live birth

What is the primary function of the hollow bones found in birds?

• To store fat

• To reduce body weight for flight

• To produce sound

• To absorb water

Which organ in birds is responsible for the exchange of gases during respiration?

• Crop

• Lungs

• Gizzard

• Stomach

Birds have a four-chambered heart. What is the main advantage of this type of heart?

• It allows mixing of oxygenated and deoxygenated blood

• It keeps oxygenated and deoxygenated blood separate

• It pumps blood only to the lungs

• It stores extra blood

Explain how the structure of a bird’s wing helps it to achieve flight.

• The wing is flat, which helps it to cut through the air.

• The wing is curved on top and flat on the bottom, creating lift as air moves faster over the top.

• The wing is heavy, providing stability.

• The wing is covered in scales for protection.

Which of the following best describes the flow of air through a bird’s respiratory system?

• Air flows in and out of the lungs in one direction.

• Air flows in a circular motion within the lungs.

• Air passes through the lungs in one direction and is stored in air sacs before and after passing through the lungs.

• Air is only stored in the crop.

A bird is observed to have a rapid heart rate and high metabolic activity. How does its circulatory system support these features?

• By mixing oxygenated and deoxygenated blood to increase speed

• By using a four-chambered heart to efficiently deliver oxygen-rich blood to tissues

• By slowing down blood flow to conserve energy

• By using a two-chambered heart to pump blood quickly

A scientist wants to compare the efficiency of the bird respiratory system to that of mammals. Which feature should she focus on, and why?

• The presence of a diaphragm, because it increases lung capacity

• The unidirectional flow of air through the lungs, because it allows for more efficient gas exchange

• The presence of alveoli, because they increase surface area

• The use of gills, because they extract more oxygen

Given that birds have high energy demands for flight, how do their respiratory and circulatory systems work together to meet these demands?

• By slowing down oxygen delivery to conserve energy

• By mixing oxygenated and deoxygenated blood to increase volume

• By ensuring a continuous supply of oxygen through unidirectional airflow and rapid circulation of oxygen-rich blood

• By reducing the number of red blood cells

A bird is flying at a high altitude where oxygen levels are low. Using your understanding of bird physiology, explain how its respiratory and circulatory systems help it survive in such conditions.

• The bird’s lungs collapse to prevent oxygen loss.

• The bird’s air sacs and efficient heart allow for maximum oxygen extraction and delivery to tissues.

• The bird stops breathing to conserve oxygen.

• The bird’s blood becomes thicker to carry more oxygen.