The Human Genome Project.

Eyes of brown? or blue?… Curly hair? or straight?… Dimples?…Freckles? …

It’s in our genes. Heredity. Our mothers and fa- thers passed on all our traits when we were born. There are also many things in our genes that we would rather avoid, such as heart disease, diabetes, cancer, arthritis, muscular dystrophy, and other ill- nesses.

Many diseases come from alterations in our genes. To decipher our genetic code, a scientific journey has begun called The Human Genome Pro- ject. The genetic code is the complete instructions of all the genes that tell our body how todevelop.

Over the years, some genes have been discovered for certain diseases. People who have a family his- tory of these diseases can be tested for the specific

gene. They will then know if they

have thisdisease,even if nosymptomsare pre-

sent. But there are many more diseases with genetic compo- nents that have not yet been uncovered. Scientists are still unclear what or which genes affect those diseases. Francis Collins MD, PHD, is the Project Director at the National Center for Human Genome Research. He said that “by uncovering all 30,000 to 40,000 genes in the human genome, we should at the same time uncover the heredity basis of most dis- eases and that would put us in a position to diagnose them better, treat them better and practice better pre- ventativemedicine.”

What are Genes? They are found in the part of the cell called the nucleus. Human cells contain 23 pairs of chromosomes, 46 in all. One member of each pair comes from the mother and one from the father. Genes occur in pairs, like the chromosomes. A chromosome is a very long chemical molecule called DNA. Genes are segments of DNA mole- cules. DNA is shaped like a twisted ladder. Rungs of the ladder are chemicals called “base pairs”. Chemical “A” is always paired up with “T” and“G”

is always with “C”. The complete human genome (all our DNA) contains three billion “base pairs”. The Human Genome Project will find the sequence of all of them. This knowledge will revolutionize our understanding of the way genes influence disease, because the genes’ “base pair” sequence is the code that determines what itdoes.

What do genes do? They give cells the instruc- tions they need to make complex molecules called proteins. Each gene code is for a different protein. A cell first converts DNA to a similar molecule called RNA. RNA carries the gene’s instructions to another part of the cell that acts like a protein fac- tory. Most proteins that come out of the factory are enzymes. Other proteins form cellstructures.

Occasionally, the gene that codes for a protein has an error in its based pair sequence. The cell then makes a protein that is not able to do what it should. This is called a mutated gene. Mutated genes play a major role in human diseases. Since genes are in- credibly small, it is difficult for scientists to isolate them. Making it easier for scientists to find disease- causing genes is the main goal of the Human Ge- nomeProject.

5. Read the text again and answer the follow-ingquestions:

1. What is the main goal of The Human Genome Project?

2. How many genes are there in the human ge- nome?

3. What is the name of the Project Director at the National Center for Human GenomeResearch?

4. How many chromosomes does A human cell contain?

5. What kind of a molecule is aprotein?

6. What is the shape ofDNA?

7. How many based pairs does a complete hu- man genomecontain?

8. How is an error genecalled?

9. What similar molecule does a cell convert DNAto?

10. What do many diseases comefrom?

5. Cells	- Specific segments of DNA that
   	control cell structure andfunction;
   Chromosomes	the functional units of inheritance.
   	- Structures in the nucleus of a
   DNA	cell.
   	- These molecules contain the
   Genes	Base Pairs which hold genetic in-
   	formation.
   Nucleus	- the unit of living matter ofwhich
   	all living things are made.

   Find the appropriate definitions to the fol-lowingwords:

Give at least two definitions of any terms from thetext.

5. Summarize what isHeredity.Talk aboutwhat you have inherited from each parent. Do you favor one parent? Do you have sisters and brothers? What have they inherited from yourparents?

5. Look at these pictures and answer the fol-lowingquestions:

Is she/he

obese fat

attractive

lovely and charming nice and friendly? medium height shortish

short / tiny