The Evolution of Respiration

Approximately how many years ago did the fish ancestor that started breathing air exist?

• 100 million years ago

• 1 billion years ago

• 500 million years ago

• 380 million years ago

What was a major milestone achieved by the fish ancestor?

• Living entirely on land

• Breathing air

• Growing to enormous sizes

• Developing fins

What system do larger life forms need to move oxygen around their bodies?

• Muscular system

• Nervous system

• Circulatory system

• Digestive system

What did the fish ancestor evolve that allowed it to breathe air?

• Lungs

• Fins

• Scales

• Gills

What is a key component of the respiratory system in humans?

• Diaphragm

• Kidneys

• Liver

• Heart

What does the respiratory system rely on to function efficiently?

• Osmosis

• Photosynthesis

• Diffusion and bulk flow

• Hydrolysis

What separates the thorax from the abdomen?

• The heart

• The stomach

• The diaphragm

• The liver

What is the primary function of alveoli?

• Producing mucus

• Gas exchange

• Storing oxygen

• Filtering blood

What is the estimated surface area provided by the alveoli in both lungs?

• 75 square meters

• 30 square meters

• 100 square meters

• 50 square meters

What anatomical feature is described as being similar to a vacuum hose to prevent collapse?

• Esophagus

• Diaphragm

• Bronchi

• Trachea