A person is declared to be dead upon the irreversible cessation of spontaneous body functions: brain activity, or blood circulation and respiration. However, only about 1% of a person’s cells have to die in order for all of these things to happen.
Explain how a person can be dead when 99% of his or her cells are still alive, and provide examples with your explanation. In 2005, researcher Woo-suk Hwang reported that he had made immortal stem cells from human patients. His research was hailed as a breakthrough for people affected by degenerative diseases, because stem cells may be used to repair a person’s own damaged tissues. Hwang published his results in a peer-reviewed journal. In 2006, the journal retracted his paper after other scientists discovered that Hwang’s group had faked the data. Discuss the implications of the incident.
In your brief discussion, determine if the incident shows that results of scientific studies cannot be trusted or if it confirms the usefulness of a scientific approach, because other scientists discovered and exposed the fraud.
QUESTION 1B Suppose that someone used nanotechnology to build little robots (called “nanobots”) that could make copies of themselves. Discuss whether or not you believe the nanobots would be alive. Explain why or why not?
In an essay of the universal nature of biochemistry, located at http://www.pnas.org/content/98/3/805.full), Norman Pace argues that carbon is the only chemical element that can form the backbones of molecules that make up living things. Determine what Pace’s argument is and explain why he believes this.
The bonding properties of water give it certain characteristics: surface tension, capillary action, universal solvent, high specific heat, and a high heat of vaporization. Indicate three reasons why you believe these properties are important to organisms that live underwater. In your own words, explain one of the following everyday phenomena in regard to the bonding properties of water, and propose one other everyday phenomenon that demonstrates the bonding properties of water:
Why do you feel cool when you sweat?
Why do paper towels (made of cellulose, another polar molecule) absorb water?
How can a water strider walk on water?
Note:please select one of the two subjects to discuss.
A group working at the University of California, Berkeley has developed “nanothermometers,” little nanoparticles that can be injected into cells to measure the temperature in various places in the cell. So far, it has been used in cells growing in a culture dish.
Indicate what you think the group will discover about the temperature in different parts of the cell. Discuss whether you believe it will be the same or different, and explain why.
The 1992 movie Lorenzo’s Oil recounts the story of six-year-old Lorenzo Odone and his battle with adrenoleukodystrophy (ALD), which is caused by a malfunctioning organelle called a peroxisome. A peroxisome is an organelle that ordinarily contains enzymes capable of breaking down long-chain fatty acids. In ALD, the enzyme is missing, and when long-chain fatty acids accumulate, muscle weakness, and loss of control result.
Select the organelle in the cell that is the most similar in structure and function to a peroxisome, and explain why you chose that organelle. Describe the function and structure of the organelle that you chose. Give examples of how a dietician might be able to help a person with ALD.