The Identical twins look so similar because identical twins have the same genetic makeup, meaning, the same DNA (same nitrogenous bases). This is because they are fertilized by the same egg, making them identical.
2. Brothers and sisters don't look exactly alike because everyone (including parents) actually has two copies of most of their genes. And these copies can be different.Parents pass one of their two copies of each of their genes to their kids
So, Identical twins look so similar because they share the same genetic makeup, while siblings have different appearances because they inherit different copies of genes from their parents.
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Student Exploration: DNA AnalysisDirections: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes.Vocabulary: allele, codon, DNA, DNA sequence, gene, genotype, identical twins, nitrogenous base, phenotype, traitPrior 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
Most brothers and sisters don’t look exactly the same. What causes most siblings to have different appearances