1. What Makes You Unique?
The fact that many children look like their parents is no accident. Heredity is the process by which parents pass characteristics on to their children. Traits that are passed on include eye color, hair color, and body build. Heredity may also include the tendency to get certain diseases. Every cell contains two structures that influence heredity- genes and chromosomes.

2. The Role Of Chromosomes
Chromosomes are tiny, threadlike pieces of matter that carry the codes for inherited traits. Chromosomes come in pairs. One-half of each chromosome pair comes from the father, the other half comes from the mother. Almost every cell in a person’s body contains 46 chromosomes- 23 from each parent.

3. Special Chromosomes
The only cells in the human body that do not have 46 chromosomes are the egg and sperm cells. They have 23 chromosomes each. When these cells unite during fertilization, they produce a cell with 46 chromosomes.

4. Special Chromosomes (cont.)
Whether you are a boy or girl was determined by your father’s sperm cell. A sperm cell contains either an “X” or a “Y” chromosome. An egg cell only contains an “X” chromosome, not a “Y”. If your father’s sperm cell contained a “Y” chromosome, you are a boy (genetic code=XY). If your father’s sperm cell contained an “X” chromosome, you are a girl (genetic code=XX).

5. The Role Of Genes
Each chromosome is divided into small sections called genes. Genes are the basic units of heredity. They carry codes that control the individual traits that you inherit. Except for identical twins, each person has a unique arrangement of genes.

6. The Role Of Genes (cont.)
People inherit two genes for every characteristic- one gene from each parent. Sometimes the two genes for one trait contain different codes. This arrangement affects how the trait appears in the child. For example, since brown eyes are dominant over blue eyes, a child must have two genes for blue eyes for that person’s eyes to be blue.

7. Factors That Affect Your Personality
Your personality is the sum total of the feelings, actions, habits, and thoughts you have. Just as the traits you inherited are unique, so is your personality. The person you become is influenced by heredity. Your personality is also shaped by your surroundings and by the choices you make. Together, your heredity, environment, and behavior make you the person you are.

8. Role Of The Environment
Your environment is the sum total of your surroundings. Your environment includes people and places. Important people are your family, your friends, and your teachers. Important places include where you grew up, where you live now, where you go to school, and where you play.

9. People
Early in life, your family is the most important influence. Your parents teach you how to act, help you develop your values, and help you develop your talents and skills.
However, during the teen years, you may be more influenced by your friends than by your family.
Your teachers introduce you to different ways of thinking about things.
You are also influenced by famous sports and entertainment personalities.

10. Places
Where you live has a strong influence on your development. It also affects what is important to you. Living in a large city may offer you many opportunities outside your home. Large cities, however, expose you to congestion and pollution.
People who live in rural areas may not have as many health care or service opportunities as people who live in the city, but they may be able to do more outdoor activities with their families.

11. The Mass Media
No matter where you live, you are likely to be influenced by television, radio, newspapers, and magazines- not to mention the internet. All of these sources of information affect your values and your thinking.

12. The Role Of Behavior
Behavior is how you act in situations that occur in life. It is the factor in your life over which you have the most control. Your actions affect who you are and who you will become. Many factors influence how you act. Your needs and your values are two of the most important factors.
Your behavior affects other people and the place where you live. If you value loyalty, you will stand up for a friend. If you value a clean environment, you may clean up your own!