Final answer:
A bifurcated tooth has two roots. Deciduous teeth emerge around 6 months of age, permanent teeth replace them between ages 6 and 12, and wisdom teeth generally emerge in early adulthood.
Step-by-step explanation:
A bifurcated tooth refers to a tooth that has two roots. Therefore, the correct answer to "A bifurcated tooth has how many roots?" is 2) Two. This is commonly seen in certain types of teeth that need to be strong and stable to perform their function, like the lower first premolars and molars which are designed for crushing and grinding food. The roots provide the tooth with nutrients and a sturdy foundation within the jawbone.
As for the different stages in human lifespan regarding teeth emergence: Deciduous teeth, commonly known as baby teeth, generally start to emerge at about 6 months of age. Permanent teeth replace these baby teeth between approximately age 6 and 12. Then, the wisdom teeth, which are the last of the molars, typically emerge in early adulthood, although it's not uncommon for them to become impacted and require removal.