Question

Explain how all humans have the same genes, but vary genetically.

Short answer

All humans have the same genes, but genetic variation occurs through differences in the DNA sequence of these genes which lead to differences in the proteins produced. These differences in proteins result in different traits and characteristics, making each individual unique.

Step-by-step solution

Define What Genes Are

Genes are segments of DNA that provide the code for creating proteins, which are then used to build our bodies and perform various functions. Every human shares around 20,000-25,000 genes.

Explain Genetic Variation

Genetic variation is the difference in DNA among individuals or populations. Even though all humans share the same genes, variations in these genes are what make individuals unique. These variations occur mainly through mutations, recombination, and also from work of other biological processes.

Explain How the Same Genes Can Lead to Different Genetic Variation

The same genes can lead to different genetic variation through differences in the DNA sequence of the genes. Even a small change in the DNA sequence can lead to differences in the protein that is produced, which can then lead to differences in traits such as eye color, height, and predisposition to certain diseases.

Provide Examples

For example, the MC1R gene is responsible for producing a protein that plays a role in hair and skin color. Different variations in the MC1R gene can lead to differences in hair and skin color, such as red hair or fair skin. Another example is the LCT gene which is responsible for producing a protein that helps digest lactose. Variations in the LCT gene can lead to lactose intolerance or lactase persistence.