- What are heredity and genetics?
- How are traits passed from one generation to the next?
- What is genetic engineering?
- How do doctors test for genetic disorders?
- What are the ethical and moral issues involved in genetic engineering?
- How can we test the morality of our decisions?
What is heredity and genetics?
How are traits passed from one generation to the next?
Humans have 23 pairs of chromosomes. In each pair, one chromosome comes from the mother and the other from the father. Twenty-two of the pairs are the same in both men and women and these are called autosomes. The twenty-third pair consists of the sex chromosomes, so called because they are the primary factor in determining the gender of a child. The sex chromosomes are known as the X and Y chromosomes. Females have two X chromosomes and males have one X and one Y chromosome. The Y chromosome is about one-third the size of the X chromosome. A sperm, the reproductive cell produced by the male, can carry either one X or one Y chromosome. An egg, the reproductive cell produced by the female, can carry only the X chromosome. When a sperm with an X chromosome unites with an egg the result is a child with two X chromosomes, a female. When a sperm with a Y chromosome unites with an egg, however, the result is a child with one X and one Y chromosome, a male. Thus, the father determines the gender of the child (Baron et al., 1998, p. 74).
What is genetic engineering?
Genetic engineering is the alteration of an organism's genetic instructions through the insertion of additional genes. In humans genetic engineering involves adding normal genes, either directly via a blood transfusion or bone marrow transplant or directly into a cluster of cells, thereby enabling the body to replace ailing cells with healthy ones. The technique is being used experimentally for hemophilia, cystic fibrosis, rheumatoid arthritis, several types of cancer, and dozens of rare diseases (Berger, 2000, p. 95).
How do doctors test for genetic disorders?
Scientists have developed a number of tests to determine whether the fetus is developing normally:
- Amniocentesis is a prenatal medical procedure performed between the 12th and 16th weeks of pregnancy in which a sample of amniotic fluid is withdrawn by syringe. It is tested to discover if the fetus is suffering from any chromosomal or metabolic disorders.
- Ultrasound sonography is a prenatal medical procedure in which high frequency sound waves are directed into the pregnant woman’s abdomen. The echo from the sounds is transformed into a visual representation of the fetus’s inner structures.
- The chorionic villus test is a prenatal medical procedure in which a small sample of the placenta is removed at some point between the 8th and the 11th week of pregnancy.
- The maternal blood test (alpha-fetaprotein test) is a prenatal diagnostic technique that is used to assess neural tube defects. This test is administered to women 14 to 20 weeks into pregnancy only when they are at risk for bearing a child with defects in the formation of the brain and spinal cord (Santrock, 1999, p. 72).
What are the ethical and moral issues involved in genetic engineering?
Gene mapping and genetic engineering create some dilemmas. Do people want to know about their genetic defects even though these defects cannot be corrected? When the issues are genetic screening and abortion, ethical values often clash with practicality and parental rights. Do parents want to bring to term a child that will have a severe disorder? One country has already instituted a policy about such disorders. In 1993, China had a program of abortions, forced sterilization, and marriage bans to avoid new births of “inferior quality” infants and raise the standards of their country. Worries abound that the information housed in people’s genes will be used to their detriment. A drop of blood or a lock of hair contains all of the genetic information a potential employer or insurer would need to determine whether someone is at risk of contracting any of a long list of debilitating diseases. Ethical dilemmas will increase in the next decade as scientists on the Human Genome Project continue to make headway in mapping out human genes (Santrock, 1999, p. 74).
Some experts get nervous about genetic technology for other reasons. One is genetic screening. This can be done today for some conditions and it will become more commonplace in the near future. Careful study of a sample of DNA can reveal how likely a person is to succumb to certain illnesses. Where the moral dilemma creeps in is whether anybody else should know, and this applies to all genetic screening. Another concern is the possibility of creating “designer babies.” Today, when a sperm and an egg unite, chance plays a major role in how the life thus created will turn out. The embryo will get half its genes from its mother and half from its father. Whether it inherits its father's tallness or its mother's blue eyes pretty much depends on a roll of the dice. But genetic engineering holds within it the promise of overcoming the random nature of heredity (Taylor, 2000, p. 7).
How can we test the morality of our decisions?
In our daily lives, we must make choices that involve questions of honesty, the treatment of other people, acting responsibly, etc. These are moral choices because they are about right and wrong. Moral choices are choices between what might be good for us personally and what would be good for others. We may want to do one thing, but we have doubts about whether we are doing the right thing. When a situation is morally doubtful we have to have some basis for deciding what to do. Should an individualistic, personal point of view be taken? Should one always be “nice” and make sure that everyone else is satisfied? When should individuals look out for themselves and when should they be concerned about others?
- Ages and Stages : “Cloning: A Twist on Creation”
- Ian Wilmut, one of the scientists who created Dolly the sheep at the Roslin Institute in Scotland, says the cells from which stem cells are derived are embryonic in nature with no evidence of the formation of a nervous system. In an article in The Globe and Mail in February 2000, he wrote that “the human nervous system will not begin to form until several weeks into a normal pregnancy. In these circumstances, I would consider using the cells of human embryo.” Dr. Wilmut points out that, under British law, a human embryo has special status but not that of a full human being.
- Discuss his view on using human embryos for research.
- What does Canadian law say about the issue of fetal rights?
- What are the legal issues involved in the question of fetal rights?
- Ian Wilmut, one of the scientists who created Dolly the sheep at the Roslin Institute in Scotland, says the cells from which stem cells are derived are embryonic in nature with no evidence of the formation of a nervous system. In an article in The Globe and Mail in February 2000, he wrote that “the human nervous system will not begin to form until several weeks into a normal pregnancy. In these circumstances, I would consider using the cells of human embryo.” Dr. Wilmut points out that, under British law, a human embryo has special status but not that of a full human being.
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