1. DNA Analysis and Diagnosis
(Category/DNA Testing)

... There are over three billion nitrogenous bases in the forty-six human chromosomes. A gene probe attempts to detect a stretch that is a few thousand bases in length, or about a millionth of the length of ...

2. Genetic Testing
(Category/Genetics)

... in a laboratory look at the baby’s chromosomes and prepare a picture of them called a karyotype. They can rule out Down syndrome by counting the number of chromosomes and making sure there are not three ...

3. Inherited Conditions
(Category/Genetics)

... was identified in 1989. It is found on chromosome 7 and controls the fl ow of chlorine in and out of certain cells. Th e normal CFTR gene is about 250,000 base pairs long. In 70% of cystic fibrosis cases, ...

4. Genetic Mutations and Cancer
(Category/Genetics)

... gene acts as a recessive gene. In other words, both tumor suppressor gene alleles on two homologous chromosomes need to be damaged before the tumor suppressor gene loses its function. Oncogenes, on the ...

5. Other Chromosomal Abnormalities
(Category/Genetics)

Most of the time, the correct number of chromosomes develops in a fetus. However, just because a fetus has the correct number of chromosomes does not necessarily mean that all of those chromosomes are ...

6. Down Syndrome - Nondisjunction During Meiosis
(Category/Genetics)

... error results when a gamete, usually an egg, has two copies of chromosome 21 instead of one copy. When a normal gamete joins with a gamete that contains two of chromosome 21, the resulting fertilized egg ...

7. Passing Genes to the Next Generation
(Category/Genetics)

... (or gap-1) phase, an S phase, a G2 (or gap-2) phase, and mitosis. During the G1 phase, a cell grows in size and prepares to replicate (or copy) the chromosomes. The S phase is the synthesizing phase, when ...

8. Chromosome Theory of Heredity
(Category/Genetics)

... the results of his experiments, Morgan determined that eye color in the fruit fly is linked specifically to the X chromosome. Morgan also proposed the idea that genes are lined up, ...

9. Early Ideas about Heredity
(Category/Genetics)

People have always been interested in how a child comes to look like other members of its family. However, scientists did not discover DNA, genes and chromosomes until relatively recently. But that did ...

10. Genes and Chromosomes
(Category/DNA Structure)

... gene are called alleles. The small differences in the alleles cause offspring to resemble their parents without looking exactly the same as either parent. Chromosomes The DNA molecule is very ...

11. Rosalind Franklin
(Category/DNA Structure)

... scientists’ understanding of DNA was nearly complete. DNA is a self-replicating material present in nearly all living organisms, mostly in chromosomes. It functions as a carrier of genetic information ...

12. Watson and Crick
(Category/DNA Structure)

... chromosomes. The eventual goal, which is somewhat remote, is the description of these activities in terms of their structure.... This might be called the chemical physics of biology.” Crick moved over ...

13. DNA Encyclopedia
(Uncategorised Content)

... a structural element of chromosomes. After World War II, Levene's chemical analyses were repeated with more sophisticated equipment and with quite a different set of results. Tests indicated that ...

14. About DNA Encyclopedia
(Uncategorised Content)

Dogs start out as puppies and kittens turn into cats. Children tend to grow up and resemble their parents and other family members. Passing down traits from parent to child, generation after generation, ...

15. DNA Structure
(Category)

Scientists in the 1830s and early 1840s knew that chromosomes were passed from one generation to the next, but they did not know what chromosomes were made of. This mystery started to unravel in 1869, ...