Revolutionaries executed Nicholas II, the last czar of Russia, along with his wife and five children, the family physician, and about a dozen servants. Many decades later, a grave said to hold the remains of the royal family was discovered. Biologists were asked to analyze DNA from the bodies. If the remains of the family were in this grave, predict how similar the DNA fingerprints would be between the parents, the children, and the unrelated individuals in the grave.

Verified step by step guidance

1. Identify the key individuals in the scenario: Nicholas II, his wife, their five children, the family physician, and the servants. Understand that the parents and children are biologically related, while the physician and servants are not.
2. Review the concept of DNA fingerprinting, which involves comparing DNA sequences to establish genetic relationships. The technique focuses on regions of DNA that vary highly among individuals, known as polymorphic regions.
3. Predict the DNA similarity among family members: The DNA fingerprints of Nicholas II and his wife would show similarities due to shared alleles among their children. Each child would inherit half of their DNA from each parent, resulting in a high degree of similarity between the DNA of the siblings and between the children and each parent.
4. Analyze the DNA fingerprints of the unrelated individuals: The family physician and the servants would not share these familial DNA markers with the royal family, resulting in distinctly different DNA fingerprints compared to those of Nicholas II, his wife, and their children.
5. Conclude that if the remains in the grave belong to the royal family and their servants, the DNA fingerprints of Nicholas II, his wife, and their children would be quite similar to each other, and significantly different from the DNA fingerprints of the unrelated individuals like the physician and the servants.

Key Concepts

DNA Fingerprinting

DNA fingerprinting is a technique used to identify individuals based on their unique DNA profiles. It involves analyzing specific regions of DNA that vary greatly among individuals, allowing for the comparison of genetic material. In the context of the royal family, DNA fingerprints can reveal genetic similarities and differences between family members and unrelated individuals.

Inheritance Patterns

Inheritance patterns describe how genetic traits are passed from parents to offspring. In diploid organisms like humans, children inherit half of their DNA from each parent, resulting in a genetic similarity of approximately 50% between parents and their biological children. This concept is crucial for predicting the degree of similarity in DNA fingerprints among family members.

Genetic Relatedness

Genetic relatedness refers to the genetic similarity between individuals, which can be quantified as a percentage. For example, siblings share about 50% of their DNA, while unrelated individuals share a much lower percentage. Understanding genetic relatedness is essential for interpreting the results of DNA analysis, particularly when comparing the royal family’s remains to those of unrelated individuals found in the grave.