Genetics E1- History of Genetics

Who was an Austrian monk that presented results of breeding experiments of peas in 1865 & whose work is considered the discovery of genes & how they are inherited?

Gregor Mendel

What does “Mendelian” inheritance refer to?

Patterns of inheritance & disorders from single gene defect

In Mendel’s experiment, he bred tall garden pea strains with short garden pea strains. In the F1 generation, all plants were tall. In the F2 generation (F1 with other F1 plants), there were both tall & short plants. Which hybrid’s characteristics were dominant?

F1 hybrids

In Mendel’s experiment, he bred tall garden pea strains with short garden pea strains. In the F1 generation, all plants were tall. In the F2 generation (F1 with other F1 plants), there were both tall & short plants. Which hybrid’s characteristics were recessive?

F2 hybrids

Which mendelian principle refers to all F1 generation offspring being identical & heterozygous when crossing 2 homozygotes with different alleles?

Law of uniformity

Which mendelian principle refers to each person possessing 2 genes for a particular characteristic but only 1 can be transmitted at any one time?

Law of segregation

Which Mendelian principle refers to the fact that members of different gene pairs segregate to offspring independently of one another?

Law of independent assortment

In what year was the genetic code discovered as the sequence of bases in DNA and the sequence of amino acids in protein?

1960s

In what year was the genome discovered?

1920s

In what year was the structure of DNA discovered by Watson & Crick?

1953

In what year was the correct number of 46 chromosomes established?

1956

What were the findings of the human genome project?

3.2 billion base pairs, human genome sequence is 99.9% same in all people, 2% of genes code for protein synthesis, & the number of coding genes is 20,000

What are applications of the human genome project?

Improved disease diagnosis, detect genetic predisposition to disease, development of drugs based on molecular info, use of gene therapy, & creation of “custom drugs” based on individual genetic profiles

A chromosomal defect is present in what percentage of spontaneous miscarriages / first trimester losses?

50%

What percentage of conceptions are chromosomally abnormal?

10% (probably more)

What percentage of neonates have atleast 1 major congenital abnormality?

3% (50% of these caused buy genetic factors)

What percent of school age children show developmental problems?

12-14%

By age 25, what percent of the population will have a genetic disorder?

5%

What percentage of the adult population will have a genetically determined medical problem, counting CAD and HTN?

50%