Student Exploration: DNA Fingerprint Analysis
Vocabulary: codon, DNA, DNA fingerprint, genotype, identical twins, nitrogenous base, phenotype, trait
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. The two navy officers shown at left are identical twins. Why do you think identical twins look so similar?
Identical twins look so similar because identical twins have the same genetic makeup, meaning, the same DNA (same nitrogenous bases). This is because by they are fertilized by the same egg, making them identical.
2. Most brothers and sisters don’t look exactly the same. What causes most siblings to have different appearances?
Most siblings have different appearances because each child inherits different gene from either one of the parents. These different genes can either be dominant or recessive depending on the parent which causes most siblings to have different appearances.
Gizmo Warm-up Most of an organism’s traits, or characteristics, are coded for by DNA. Traits are determined by a unique sequence of nitrogenous bases in the DNA molecule. Except for identical twins, the order of every individual’s nitrogenous bases is unique. Scientists use this fact when studying DNA fingerprints—patterns of bands made from analyzing a strand of DNA. In the DNA Fingerprint Analysis Gizmo™, you will analyze DNA fingerprints of frogs. 1. Select the POPULATION tab. What are the three main traits that vary between the frogs?
The three main traits that differ between the frogs are the spots on their body, the color of the eyes and the color of the skin.
2. Which frog would you expect to have the most similar DNA to frog A? Why?
Frog A would have the most similar DNA towards frog I. This is because they both contain the same traits, for example, both have spots on their body, both are color orange and have the same eye