News. The invention of the Polymerase Chain Reaction (PCR) radically changed biology. The technique was considered so important that the Nobel Prize was awarded to its inventor, Kary Mullis, in 1993.Thanks to this technique, very small samples of DNA (from as little as a single cell) can be analyzed.ews. The invention of the Polymerase Chain Reaction (PCR) radically changed biology. The technique was considered so important that the Nobel Prize was awarded to its inventor, Kary Mullis, in 1993.
The smallest prime number, according to primality as defined by modern mathematicians, is 2. To be prime, a number must be divisible only by itself and 1. All other numbers are known as composites.
Tell your students that each of the circled numbers is a prime number. Explain that a prime number is any number that has only two factors, 1 and itself. It is important to let students know that 0 and 1 are not considered prime numbers. Review the first couple of numbers on the Hundreds Chart as a class, deciding whether each is prime or composite.