2: THE HISTORY OF CYTOGENETICS Flashcards
- expressed it in the famous aphorism “Omis cellula e cellula” (all cells come from cell)
All organisms will inherit their genetic information specifying their structure and function that comes from their parents.
RUDOLF VIRCHOW
- “Heredity appears as a consequence of the genetics continuity of the cells by division.”
WILSON
Observations on the germ cells made by Van Beneden, Flemming, Strasburger, Boveri, and others gave support to the theory of continuity of the germ plasm proposed by ________ in 1883.
Weismann
This theory stated that the transference of hereditary factors from one generation to the next takes place through the continuity of what he called ‘germ plasm’, located on the sex elements, and not through somatic cells.
theory of continuity of the germ plasm by Weismann
is a combination of egg cell and sperm.
Germ cells
The discovery of fertilization in animals, foreseen by __________
O. Hertwig
The discovery of fertilization in animals, foreseen by O. Hertwig but observed directly by H. Fol (1879), and in plants, by __________ led to the theory that the cell nucleus is the bearer of the physical basis of heredity.
Strasburger
The discovery of fertilization in animals, foreseen by O. Hertwig but observed directly by H. Fol (1879), and in plants, by Strasburger, led to the theory that the cell ________ is the bearer of the physical basis of heredity.
nucleus
- postulated that chromatin, the substance of the nucleus that constitutes the chromosome, must have a liner organization.
ROUX
Roux postulated that chromatin, the substance of the nucleus that constitutes the chromosome, must have a _____________________.
liner organization
- stated that the hereditary units are disposed along the chromosomes in an orderly manner.
WEISMANN
The fundamental laws of hereditary were discovered by ___________ in 1865, but at that time cytologic changes produced in the sex cells were not sufficiently known to permit an interpretation segregation of hereditary characters.
Gregor Mendel
Little attention was paid to Mendel’s work until the botanists ______________________________ in 1901 independently rediscovered Mendel’s laws.
Correns, Tschermack, and De Vries
_________ suggested that sex determination was related to some special chromosomes, this theory was later corroborated by Stevens and Wilsons (1905)
McClung (1901-1902)
The experimental demonstration of the chromosome theory of heredity was finally established by ___________________, but it was Morgan and his collaborators, Sturtevant, and Bridges, who assigned to the genes (Johannsen), or hereditary units, define loci within the chromosomes.
Boveri and Baltzer
The experimental demonstration of the chromosome theory of heredity was finally established by Boveri and Baltzer, but it was __________________________________________, who assigned to the genes (Johannsen), or hereditary units, define loci within the chromosomes.
Morgan and his collaborators, Sturtevant, and Bridges
Thereafter experimental research on heredity and evolution became a separate branch of biology which _________ in 1906 called “genetics”.
Bateson
___________ published his investigations into inheritance of pea plants.
Gregor Mendel
_____________ suggested that chromosomes are involved with inheritance
Theodor Boveri
____________ observed chromosomes in grasshopper cells.
Walter Sutton
Mendel’s work was rediscovered by three scientists:
Hugo De Vries, Erich von Tschermack, and Carl Correns.
_______________ discovered that some diseases must be inherited.
Archibald Garrod
__________________, working independently, suggested that each egg of sperm cell contains only one of each chromosome pair.
Sutton and Boveri
________________________________, working independently, proposed that certain chromosomes determine sex.
Edmund Beecher Wilson and Nettle Stevens
single Y chromosome determines
maleness
two copies of the X chromosome determines .
femaleness
________________ gave the term ‘genetics’
Bateson
_______________ used the term ‘gene’ to describe the carrier of heredity, to describe an organism’s genetic makeup, and ‘phenotype’ to describe an organism’s outward appearance.
William Johannsen
_________________ proved that genes are carried on chromosomes. He also showed that some characteristics are carried on the sex chromosome.
Thomas Hunt Morgan
_________________ mapped the genes on the fruit fly’s sex chromosomes.
Alfred Henry Sturtevant
___________________________________ discover that x-rays can be used to study the molecular structure if simple crystals, such as salt.
Sir William Henry Bragg and his son
_________ published the “The Theory of the Gene”
Morgan
__________________ discovered ‘transformation’ in bacteria.
Frederick Griffith
__________________________________ used bacteria to show that DNA is the hereditary material
Oswald Avery, Colin Macleod, and Maclyn McCarty
_______________ finds that the amounts of adenine and thymine in DNA are about the same, as area the amounts of guanine and cytosine.
Erwin Chargaff
_________________________ proposed that the DNA Molecule is a double-stranded helix.
James Watson and Francis Crick
________________________ work out the genetic code
Marshall Nirenberg and Heinrich Matthaei
DNA from virus is sequenced for the first time by _________________________________________ working independently.
Frederick Sanger, Walter Gilbert and Allan Maxam,
_________________ discovered the Polymerase Chain Reaction (PCR), enabling lengths of DNA to be multiplied.
Kary Mullis
_______________________________________________________________ analyze mitochondrial DNA in different human races. They declared that humans have a common ancestor who lived 200,000 years ago.
Rebecca Cann, Mark Stoneking, and Allan Wilson
The first human gene is sequenced by ___________________________ . It is the gene that causes cystic fibrosis
Francis Collins and Lap-chee Tsui
The Human Genome Project is launched.
1990
_______________ became the first genetic disease to be treated using gene therapy.
Cystic Fibrosis
The genome of H. influenzae is sequenced. This is the first complete genome of an organism
1995
First draft sequences of the human genome are released at the same time by the Human Genome Project and Celera Genomics.
2000
The Human Genome Project is successfully completed on April 14.
2003
