Understanding the Olfactory System

The video explores the olfactory system, highlighting its role as both a primitive and sophisticated sense. It explains how olfactory neurons detect a wide range of odors through a lock-and-key mechanism involving receptors. The genetic basis of olfaction is discussed, emphasizing the significant number of genes dedicated to this sense in humans and other mammals.

What is often referred to as the most primitive sense?

• Vision

• Hearing

• Olfaction

• Taste

Where are olfactory sensory neurons located?

• On the tongue

• In the ears

• At the top of the nose

• In the brain

Approximately how many odors have been identified?

• 1,000

• 10,000

• 100,000

• 1,000,000

What type of molecules are most odors?

• Metallic molecules

• Inorganic molecules

• Large molecules

• Organic molecules

How do receptors detect odor molecules?

• Through sound waves

• By vibrating

• By changing color

• Through a lock-and-key mechanism

What happens when an odor molecule fits into a receptor?

• The receptor moves to another location

• The molecule is destroyed

• The cell activates and signals the brain

• The receptor changes color

How many types of olfactory receptors do humans have?

• 450

• 1,000

• 10,000

• 100

What percentage of human genes are devoted to the sense of smell?

• 10%

• 5%

• 2%

• 1%

In comparison to humans, what percentage of genes in mice are devoted to olfactory receptors?

• 1%

• 2%

• 5%

• 10%

What does the evolutionary commitment to the sense of smell indicate?

• It is a recent development

• It has no genetic basis

• It is not important

• It is significant for survival