Genetics Test 1 Flashcards
Be able to describe a virus.
Neither prokaryotic nor eukaryotic. There is even debate on whether they are living or not. Cant replicate alone, it needs to infect a cell.
Prokryotes
Unicellular
No nucleus
Not membrane bound
Not s much in them
DNA isnt tightly packed
Single circular chromosome
Eukaryotes
Yes nucleus
Can be unicellular or multicellular
Multiple linear chromosomes within nucleus (tightly packed around histones)
Understand the implications of the fact that all organisms use similar genetic systems.
All living things use similar genetic systems and are constructed from cells
When is something a good genetic model
Small, short lived, lots of offspring, genetic similarity, can be mutated
Give some examples of how genetics is important in today’s society.
Help affect traits and health
Important in agruculture (selective breeding and GMOs
Medicine
Development, evolution, etc.
Nucleic acids
encode the information required for the creation and maintenance of biological creatures.Nucleic acids are polymers of nucleotides.
Know the four nitrogenous bases in DNA and which ones are purines vs. pyrimidines (2 vs. 1 ring) and how this determines constant width of the DNA helix
Purines (2) - adenine and guanine
Pyrimidines (1)- thymine and cytosine
Pairs: adenine and thymine; guanine and cytosine
antiparallel
antiparallel - they are the same but go in opposite directions
DNA replication requirements
- Template must be single stranded
- Raw materials (dNTPs)
- Enzymes need to read template and assemble raw materials
Be able to describe all the various steps of DNA synthesis (general)
Initiation, unwinding, elongation, termination
initiation
Initiator proteins bind to origin and separate stands of a small section of DNA
Unwinding
- DNA Helicase-
* Unwinds DNA
*ssDNA binding protein -
*Keeps the strands separated
*DNA gyrase -
Relieives supercoiling
List and explain at least 3 differences between prokaryotic and eukaryotic DNA replication.
Single origin in prokaryotic and several in eukaryotic
The gyrase relieves supercoilding of helicase in prokayriotics and the topoisomerase does it in Eukaryotic
Replication is continuous in prokaryotic and based on cell cycle in eukaryotic
Binary fission
starts on specific place on circular chromosome (origin of replication). The origins move away from each other and SMC encircle DNA and help chromosomes from getting tangled in replication. Then cell walls form.
Cell reproduction in eukaryotes compared to prokaryotes
Similar to prokaryotes but way more complex.
Mitosis
single nuclear division. Newly formed cell is identical
Meiosis
two divisions, newly formed cell is half
Aneuploidy
An increase or decrease in # of individual chromosome
types of anueploidy
nullisomy, monosomy, trisomy, tetrasomy
Nullisomy
loss of both homologous pairs of chromosomes
Monosomy
loss of a single chromosome
Trisomy
gain of a single chromosome