Understanding the Marvel of Teeth

Teeth are remarkable structures that break down food while resisting damage. They consist of a hard enamel layer and a tough dentin layer, formed by ameloblasts and odontoblasts. Enamel cannot repair itself, but dentin can. Despite differences in shape across species, the tooth formation process is similar. Evolutionary changes have adapted teeth to various diets, with the tribosphenic molar as a common ancestor. This adaptability has contributed to the success of mammals in diverse environments.

What two properties make teeth unique compared to other materials?

• Flexibility and elasticity

• Hardness and toughness

• Transparency and strength

• Softness and durability

What is the primary component of the enamel layer in teeth?

• Keratin

• Collagen

• Organic fibers

• Calcium phosphate

Which cells are responsible for secreting dentin?

• Fibroblasts

• Odontoblasts

• Chondroblasts

• Ameloblasts

How do cows' molar teeth differ from those of cats?

• Cows have sharp crested molars, while cats have flat molars.

• Cows have flat molars with parallel ridges, while cats have sharp crested molars.

• Cows have blunt molars, while cats have flat molars.

• Cows have triangular molars, while cats have zigzag molars.

What is the common ancestral form of modern mammalian molars?

• Quadrate

• Tricuspid

• Tribosphenic

• Bicuspid

Who developed the basic model for the evolution of the tribosphenic molar?

• Louis Agassiz

• Edward Drinker Cope

• Richard Owen

• Charles Darwin

What evolutionary change led to the formation of triangular crowns in teeth?

• Addition of more cusps

• Alignment of cusps in a row

• Pushing cusps out of line

• Removal of the back shelf

How do human molars differ from those of cats and dogs?

• Human molars have a front cusp and no shelf.

• Human molars have a raised shelf and no front cusp.

• Human molars have parallel ridges like those of cows.

• Human molars are bladed like those of cats and dogs.

What role do mammalian teeth play in the success of mammals?

• They provide mammals with camouflage.

• They help mammals breathe underwater.

• They allow mammals to fly.

• They enable mammals to consume diverse forms of food.

What is the significance of the tribosphenic molar in mammalian evolution?

• It was the first tooth to appear in mammals.

• It served as a starting point for the evolution of specialized teeth.

• It was unique to herbivorous mammals.

• It was only found in aquatic mammals.