If you wonder about questions like these, you have already started your study of genetics. Genetics is an interesting field of study, and it is also an important one. As you read the following section, consider reasons why studying genetics is important.
The principles of heredity explain how one generation of a plant or an animal shares similar characteristics with the generations that came before it. Corn plants come from the seeds of corn plants. Puppies are born from dogs that were once puppies born from another generation of dogs. Dogs and corn have very different traits. Principles of heredity always apply, but one of those principles is that some traits vary. Tall parents tend to have tall children, but everyone probably knows an example where that is not true. A short child born to tall parents may be exhibiting a characteristic that had not been seen in parents, or grandparents, or in their parents or grandparents.
Characteristics like height, eye color, and hair color are obvious through observation. But not all inherited traits are obvious. Some people may inherit the tendency to develop a certain disease, for example. You cannot see that in another person or even in yourself. Whether someone actually develops the disease, however, might depend on factors in their environment.
Although the field of genetics is interesting to many people, scientists study genetics to learn important information. One area of study is the role of genetics in how diseases or disease resistance may be passed from one generation to another through particular traits. You might imagine how this information would be helpful in preventing or treating diseases in humans, in animals, or in plants. Farmers are especially interested in plants that are resistant to diseases that could threaten to ruin an entire crop, for example. Scientists who study genetics are interested in many aspects of genetic material, including how traits get passed from one generation to another.
Based on the reading, list one trait that can vary between individuals within the species and one trait that is a species trait.
In the reading, an example is given of a trait that is both inherited and is influenced by the environment. Describe that example.
One trait that can vary between individuals within the species is height. Tall parents can have both tall and short children, indicating that height can vary from person to person.
One trait that is a species trait is eye color. All individuals within a species, such as humans, have eye color, but the specific color may vary between individuals.
The example given in the reading is the inheritance of the tendency to develop a certain disease. While the specific disease was not mentioned, it is stated that some people may inherit the tendency to develop a disease, but whether they actually develop it depends on environmental factors. This example illustrates how both genetic and environmental factors can contribute to the development of a certain disease.