Each PCR cycle replicates one DNA molecule. This cycle lasts about 2 minutes where the Denaturation (where the DNA double helix is separated) phases occur, Bonding (where prmiets begin to establish complementary hydrogen bonds to the nitrogenous bases of the two DNA strands) and Synthesis (Where DNA polymerase begins to create new strands of DNA). Prior to the first round of PCR there was a DNA sample. However, after one cycle this sample was replicated, so the PCR reaction will follow with 2 DNA samples.
It is not possible for Sarah and Thomas to develop cystic fibrosis but it would be possible for one of their children to inherit it. Both Sarah and Thomas are heterozygous and in a heterozygous pair of alleles the dominant allele is the one that will present. Because Sarah and Thomas both have the heterozygous allele combination Ff they are carriers which means that they will not experience symptoms of cystic fibrosis but they could pass cystic fibrosis onto one of their children.
The students with the purple shirts are moving through the gym doors most often.
Explanation:
The students with the purple shirts represent potassium ions
Potassium ions move freely across the membrane by passive transport and are important in maintaining membrane potentials
The movement of sodium ions is through active transport therefore this is a process that requires energy (ATP) and thus these ions are less likely to move across the membrane often
