GENETIC FOUNDERSWatson, Crick, Franklin, & Mendel

WHAT IS DNA?

DNA is the common name for Deoxyribonucleic acid, the chemical of life. This nucleic acid is made of long chains of nucleotides, which are complex molecules present in the nucleus of all cellular forms of life and many viruses.

WHAT IS DNA?

DNA carries along its length a series of coded chemicals called genes, which gives instructions for passing on hereditary characteristics, such as leaf shape, claw length, hair or eye color as well as susceptibility to some diseases.

WHAT ARE BASES?

One of four kinds of nucleobases. A base, is a ring structure containing nitrogen and is attached to the 1’ carbon atom of the deoxyribose sugar.

WHAT ARE THE 4 DNA BASES?

The four bases used by DNA are:

o Adenine (A)o Guanine (G) which are purines!!!o Thymine (T)o Cytosine. (C) which are pyrimidines!

WHAT ARE THE 4 RNA BASES?

The four bases used by RNA are:

o Adenine (A)o Guanine (G) which are purines!!!o Uracil (U)o Cytosine. (C) which are pyrimidines!

WHO WAS ROSALIND FRANKLIN?

Rosalind Franklin was a graduate in physical chemistry and had been working since 1947 on x-ray methods in Paris. She was hired to work with nucleic acids and x-ray diffraction of DNA.

WHO WAS ROSALIND FRANKLIN?

Franklin soon found out that by bundling super thin strands of DNA and zapping them with a super fine x-ray beam there were two forms of hydration. She spoke at a seminar that James Watson had attended.

WHO WAS ROSALIND FRANKLIN?

She intrigued James Watson so much that he returned home to began building the first model of DNA with Francis Crick.

WHO WAS WATSON & CRICK?

James Watson worked with Crick and discovered the structure of the DNA molecule. He was awarded the Nobel Prize for Physiology or Medicine in 1962. He was a gifted young man who had a deep interest in animals (especially birds).

WHO WAS WATSON & CRICK?

Professor Francis Crick was a British physicist, molecular biologist and neuroscientist. He was interested in the fundamental problem of learning how genetic information might be stored in molecular form.

WHO WAS WATSON & CRICK?

Watson and Crick produced and demonstrated an erroneous first model of DNA that mainly showed how little they really knew about the process. Rosalind Franklin was very critical of their model. Watson and Crick viewed this as a competition and vowed to beat Franklin.

WHO WAS WATSON & CRICK?

Franklin was unwilling to cooperate with Watson and Crick in creating a DNA model. However, they developed another model after discovering that hydrogen bonds were at the core of the helix providing a way to unzip the two complementary strands.

WHO WAS GREGOR MENDEL ?

Mendel was an Austrian monk who is often called the “father of genetics” for his study of the inheritance of traits in pea plants. Between 1856 and 1863 Mendel cultivated and tested some 28,000 pea plants. His attraction to research was due to his love of nature.

WHAT DID HE DO?

He was curious as to how plants obtained atypical characteristics. He took two such plants and planted them side by side. He found that plants’ respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment.

HETEROZYGOUS VS. HOMOZYGOUS

Heterozygous – possessing two different forms of a particular gene, one inherited from each parent.

Homozygous – having the same allele at one or more gene location on a homologous chromosome segment.

ALLELES

One member of a pair or series of genes that occupies a specific position on a specific chromosome.

INCOMPLETE DOMINANCE

A heterozygous condition in which both alleles at a gene location are not completely dominant over the other. So both are partially expressed and which often produces an intermediate phenotype.

SEX LINKED GENES

A gene located on a sex chromosome, usually the X-chromosome. Examples would include red/green color blindness, hemophilia, congenital night blindness, high blood pressure, and duchene muscular dystrophy.

BIOTECHNOLOGY

The use of microorganisms, such as bacteria or yeasts, or biological substances, such as enzymes, to perform manufacturing processes. Applications include production of certain drugs, synthetic hormones, and bulk food stuffs.

GENE THERAPY

A technique for the treatment of genetic disease in which a gene that is absent or defective is replaced by a healthy gene.

STEM CELLS

An unspecialized cell that gives rise to a specific specialized cell, such as a blood cell.

CLONES

A DNA sequence, such as a gene, that is transferred from one organism to another and replicated by genetic engineering techniques.

REPRODUCTIVE TECHNOLOGIES

The use of medical techniques, such as drug therapy, artificial insemination, or in vitro fertilization, to enhance fertility.

SELECTIVE BREEDING

When certain organisms or plants are selected based on desirable characteristics. This allows for our species to increase the efficiency of the animals and plants we breed such as increasing milk yield from cows by continuously breeding selective cows with one another to produce a hybrid.

GENETIC COUNSELING

The counseling of prospective parents on the parents on the probabilities and dangers of inherited diseases occurring in their offspring and on the diagnosis and treatment of such diseases.

GENETIC COUNSELORS

Counselors who are specifically trained to interpret genetic information and consult with parents based on this information.

HUMAN GENOME PROJECT

An international research effort to map and identify the role of all genes in the human genome.

GENETIC SCREENING

The analysis of DNA samples to detect the presence of a gene or genes associated with an inherited disorder.