Molecular Genetics part 1 Flashcards
What is a gene?
A specific portion of DNA that guides the production of specific proteins
How many pairs of chromosomes do humans have?
23
What is the genotype for a female?
XX
Genotype of male
XY
How many pairs of autosomes do humans have?
22
What do scientists look for when creating a karyotype?
- Chromosome length
- Chromosome banding pattern
- Presence of satellites on chromosome
- Position of centromere in chromosome
Conjugation:
The transfer of DNA from one bacterial cell to another
Where are plasmids found?
In bacteria
Histone proteins:
Proteins that coil DNA tightly into chromosomes
What would cause sickness or death if injected into an organism?
- Virulent pneumonia
- Avirulent pneumonia mixed with heat treated virulent pneumonia
Which scientist used radioactively coated phosphorus and sulphur to prove DNA was the transformation factor?
Hershey and Chase
What did Avery, McCarty and MacLeod do?
The isolated virulent carbohydrates, DNA and protein and mixed it with avirulent bacteria to prove that DNA could move from one cell to another.
What was the transformation factor in Griffith’s experiment in pneumonia?
DNA
Rosalind Franklin
Used X-ray diffraction to take pictures of the structure of DNA
The following is Chargaff’s rule: [A] = [T] and [C] = [G]. Explain this rule.
The concentration of adenine equals that of thymine, and the concentration of cytosine equals that of guanine
What did photo 51 reveal about the structure of DNA?
DNA has a helical structure
What makes up a complete nucleotide?
- Deoxyribose sugar
- Phosphate
- Nitrogenous base
What kind of a backbone does DNA have?
Sugar phosphate
What makes up the genetic code in DNA?
The pairing of nitrogenous bases
What direction does gene replication occur?
5’ to 3’
In which phase of DNA replication is the replication bubble created?
Initiation
In replication the leading strand is synthesized ______ and the lagging strand is synthesized _____
- Continuously
- Discontinuously
In replication, where do the replication forks form?
At several points along the DNA strand
Helicase:
An enzyme that unwinds the DNA helix at several replication forks
Binding protein:
Holds the strands of DNA open at each replication fork so they do not recoil
Leading strand:
Is synthesized continuously 5’ to 3’
Lagging strand:
Is synthesized discontinuously 5’ to 3’
Polymerase 3
Synthesizes a strand of complementary DNA continuously in the 5’ to 3’ direction on both leading and lagging strands
Primase:
Puts down a short RNA primer on the lagging strand
Polymerase 2:
Proof reads the newly synthesized DNA
Ligase:
Joins the Okazaki fragments together to make one smooth strand of complementary DNA
What ecosystem service do pollinators provide?
Pollination
Semi-conservative replication
Is a replication process. Each new molecule has an old strand and a new strand of DNA. This precise replication allows genetic information to be passed down from generation to generation
