How have the genes of the original single-cell ancestor been passed on to living things for 4 billion years? By the continual division and replication of the original ancestor's DNA molecule, the ancestor's genes are now a part of every living thing on the planet.
Why is DNA called the "silent witness" to a crime? Any trace of a person, such as hair, skin, blood, or saliva, contains their DNA code, which can be definitive evidence of their presence at a crime scene.
When scientists cloned Dolly, what process did they use to reverse the specialized adult cell instructions? Scientists put the cell into hibernation by starving it of nutrients, thus causing the cell to revert to a state that was capable of creating life.
What is the benefit of putting a human gene into a cow's DNA? A cow with human genes in its DNA can produce milk with human protein, which is then used as medicine to treat diseases such as cystic fibrosis.
Why are genetic twins who have been separated at birth almost perfect genetic subjects to study? Since twins who are separated at birth grow up in different environments, scientists can isolate which behaviors are caused by genes and which behaviours are caused by the environment in which people are raised.
How is the present-day gene sequencing a type of "scientific gold rush"? There is much gene information to analyse, and scientists are rushing to discover the many gene sequences that have a medical use and therefore the potential for generating large financial returns.
How will gene therapy someday offer people an increase in life span? Some fatal diseases are caused by mutations in our genes. If disease-causing genes are isolated and treated, life spans may be extended