Lecture questions Exam 1 Flashcards
What are the three main branches of genetics?
TMP: Transmission, Molecular and Population genetics.
Name the structure that is made of chromatin that carries and transmits many genes.
Chromosome
What is the name for an inherited structure that is made of DNA and codes for a trait/phenotype.
Gene.
What is a genome?
complete set of gene instructions. codes for all genes known for an organism.
Name for a variant form of a gene.
allele.
Term for a set of genes with no differing alleles.
monomorphic.
Term for a set of genes with differing alleles.
Polymorphic.
What makes up genetic material? (SERV)
- Store large amounts of info
- Encode the phenotype
- Replicate itself faithfully (mostly)
- Vary; be able to vary/mutate
What are the three components of the primary structure of DNA?
- phosphate
- sugar
- nitrogenous base
What charge does the phosphate component have?
negative.
Name the type of covalent bond phosphate forms with sugar in DNA structure.
phosphodiester bond.
What type of sugar composes DNA?
ribose.
Ribose forms phosphodiester bonds with which carbons?
3’ and 5’.
The nitrogenous base connects to the deoxyribose at which carbon and using what type of bond?
1’ carbon; covalent bond.
Why is the ribose sugar considered “deoxy?”
because it lacks an oxygen molecule at the 2’ carbon.
What are the two groups of bases?
Purine and Pyrimidine
What are the two purine bases?
Adenine and Guanine.
What are the two pyrimidines?
Thymine and Cytosine.
What type of bonds do bases form with each other?
hydrogen bonds.
Adenine and Thymine form how many hydrogen bonds?
2.
Cytosine and Guanine form how many hydrogen bonds?
3.
Explain Chargaff’s rules.
DNA for A &T plus DNA for C &G should equal 100%.
DNA for A equals DNA for T, DNA for C equals DNA for G.
The secondary structure of DNA forms…
2 antiparallel and complimentary DNA polynucleotide strands. They can denature and pull apart. They run in the 5’ to 3’ direction.
What type of bond is formed between adjoining nucleotides?
a phosphodiester bond is formed between the 5’ phosphate group and the 3’OH group of adjoining nucleotides.
What holds the secondary structure together?
the hydrogen bonds between nitrogenous bases.
IS the double helix right or left handed in curve?
right-handed.
Who, in 1833, described the nucleus of the cell?
Brown
What two scientists, in 1839, proposed cell theory?
Schleiden and Schwann.
Mendel’s work was first published in what year?
1866.
Who, in 1869, discovered nuclein in the nucleus of white blood cells?
Miescher
In what year were histones isolated from the nucleus?
1884.
In what year was the nucleus identified as the basis of physical heredity?
1887.
Mendel’s work was “rediscovered” in what year?
1900.
Who, in the late 1880’s, determined that DNA was made of nitrogenous bases?
Kossel.
Who in 1910, proposed tetranucleotide theory?
Levene.
Who in 1928 demonstrated the transforming principle?
Griffith.
In 1944, what trio demonstrated that the transforming principle was DNA?
Avery, McLeod, and McCarty.
Who, in 1947, began X-ray diffraction studies of DNA?
Ashbury
Who, in 1948, discovered regularity in base ratios of DNA?
Chargaff and colleagues.
In 1952, who discovered that DNA was the genetic material found in bacteriophage?
Hershey and Chase
Who, in 1953, devised the secondary structure of DNA?
Watson and Crick.
What duo, in 1956, discovered that some viruses use RNA as genetic material?
Fraenkel-Conrat and Singer.
Who, in 1951, besides Ashbury, began to study X-ray differential imaging of helical, antiparallel DNA strands?
Franklin-Wilkins
