Imagine having someone who looked like you, talked like you, even walked like you. Maybe you would make your twin do the things you hate, like clean your room or eat your peas. Your parents would never even know. Some people are born with an identical twin. However, did you know that scientists are experimenting with making twins from animals and people that are already alive?
Growing twins from things that are already alive is nothing new in the plant world. Creating new plants by cutting off a part of the plant and planting it the cutting is the second most popular way to start new plants. These cuttings make twins that are exactly like the parent plant. Farmers take cuttings from a plant that they think is better than the other plants. Maybe the fruit is extra tasty or the plant needs less water. For example, all navel oranges grown in the U.S. come from one sweet orange tree that grew in Brazil almost 200 years ago. The oranges spread through cuttings, and each new orange tree has the exact same directions as the parent plant. Cloning
is the process of making new living things with the exact same set of directions as something that's already alive.
All of this from a single tree!
So what's the big deal about cloning if it happens all the time? Well, scientists are trying to out-do Mother Nature by making twins of their own in their labs. They can try by removing the directions from the nucleus of a cow's egg cell. Remember, an egg cell has only half the directions a new living thing needs. The other half comes from the boy cell. When the two come together, the child will have a whole set of new directions. Once the directions are removed, we can take a different set of directions from another cow and put them in the egg. This cow is a twin of the first cow that the directions came from. It is called nuclear transfer
when we remove the directions from one egg and put in a whole new set of directions from another living thing.
Do you think we look like twins? I don't think we look like twins.
Aside from making twins to eat our peas and do our work around the house, why would we need clones? Many doctors think clones can be used to help people with diseases that attack the heart, brain, and other body parts. Doctors are doing this by turning back the clock to use a special kind of cell called stem cells. With a push in the right direction, these cells can grow into any other kind of cell in our bodies. They can become nerve cells, brain cells or heart cells. Fully grown people still have some stem cells. However, the most promising ones come from embryos that form just four days after boy and girl cells come together. Many people worry about this because removing stem cells ruins the embryos. They believe that this destroys a human life. This is why the U.S. government put a ban on giving money for embryonic stem cell research. A ban
means there is a rule or law preventing something from happening. Over time, the U.S. government has been changing these rules.
Cloning can also be used to change the food we eat. Picture an orange with added calcium for healthy bones. How about an apple that tastes like a grape? Farmers have worked for years to make their crops better. They might pick apples that live through harsh winters better or do not get diseases. They then use these super apples to make new apple trees. The genetics lab has made this science more exact. You do not even have to cross two plants to make new plants. The directions for making calcium might come from a cow and these can be added to the orange's directions. A GMO
is a genetically modified organism, which means people have changed one or more parts of that living thing's directions by adding in directions from a different living thing. In the U.S. you often find GMOs in corn, soybeans, and cotton crops.
That's a lot of corn to genetically modify.
Living things have been making twins since the beginning of life. Now people are getting into the game. Many people say that cloning is "playing God" and should not be done. Others feel it could help us to find cures or make better food. What do you think?Resources:
"Cloning." UXL Complete Life Science Resource. Ed. Julie Carnagie and Leonard C. Bruno. Detroit: UXL, 2010. Science In Context. Web. 16 Mar. 2013.
"Cloning." World of Biology. Gale, 2010. Science In Context. Web. 16 Mar. 2013.
"Genetically modified organism." Environmental Encyclopedia. Gale, 2011. Science In Context. Web. 16 Mar. 2013.
"Special Harvard Commentary: Stem Cells 101." Harvard Health Commentaries. 21 Aug. 2006. Web. 16 Mar. 2013.
"Stem cells." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 4th ed. Detroit: Gale, 2008. Rev. 16 Jan. 2013. Science In Context. Web. 16 Mar. 2013.
Stern, Kingsley R. Introductory Plant Biology. Boston, MA: McGraw-Hill, 2000. Print.
Wolf, Don P. "Cloning." AccessScience. McGraw-Hill Education, 2012. Web. 16 Mar. 2013.