Cicada Life Cycles and Mathematics

The video explains how prime numbers relate to cicadas, large insects that emerge in cycles of 13 or 17 years. These cycles, being prime numbers, help cicadas avoid predators by minimizing synchronization with predator cycles. In 2021, billions of cicadas on a 17-year cycle will emerge in parts of the United States. The video also discusses how these cycles reduce the chances of predators killing cicadas by only aligning with predator cycles infrequently, such as every 85 years for a 5-year predator cycle. The video concludes with a reminder to watch for cicadas in 2021.

What is a prime number?

• A number divisible by 2 and 3

• A number divisible by 1 and itself only

• A number with more than two factors

• A number that is always even

Why do some cicadas emerge every 13 or 17 years?

• To ensure they have enough food

• To avoid predators by aligning with their cycles

• To synchronize with the lunar cycle

• To avoid harsh weather conditions

How many cicadas can emerge per acre during a 17-year cycle?

• 1.5 million

• 500,000

• 750,000

• 2 million

What is the least common multiple of 5 and 17?

• 85

• 95

• 65

• 75

How often would a 13-year cicada species align with a 2-year predator?

• Every 20 years

• Every 15 years

• Every 13 years

• Every 26 years

What mathematical concept helps explain the infrequency of cicada and predator cycle alignments?

• Arithmetic mean

• Least common multiple

• Greatest common divisor

• Prime factorization