Unit 6 1/30/2025 Flashcards
Who performed X-Ray Crystallography of DNA in the 1950s?
Rosalind Franklin
What technique did Rosalind Franklin use to study DNA?
X-Ray Crystallography
What did Rosalind Franklin’s work on DNA reveal?
A pattern that was regular and repetitive
Who analyzed DNA samples from different species?
Edwin Chargaff
Chargaff’s work contributed to understanding the base pairing in DNA.
What rule did Edwin Chargaff discover regarding adenine and thymine?
The amount of adenine equals the amount of thymine
This is known as Chargaff’s first rule.
What rule did Edwin Chargaff discover regarding cytosine and guanine?
The amount of cytosine equals the amount of guanine
This is known as Chargaff’s second rule.
What type of bond connect A to T and G to C in DNA? How many are there?
Hydrogen bonds, 2,3
What nucleotides are Purines? What characteristics do they have?
What nucleotides are pyramidines? What characteristics do they have?
What’s the result of Adenine and thymine connecting with 2 hydrogen bonds compared to cytosine and guanine?
Adenine and thymine are easier to break apart due to the less amount of bonds
How might hydrogen bonds affect DNA replication?
Hydrogen bonds allow for the DNA strands to be easily separated during the replication process
What’s the backbone of the DNA structure? What’s different about it compared to the nucleotides?
Sugar phosphate
It doesn’t contain genetic material
The 5’ end of DNA strands has a free ___ while the 3’ end has a free ____
phosphate group
hydroxyl group
What’s a plasmid?
Small circular pieces of DNA in prokaryotes and eukaryotes
What is the primary source of heritable information?
DNA
Where is genetic information stored?
In DNA
How is genetic information passed from one generation to the next?
Through DNA
What is the exception to DNA being the primary source of heritable information?
RNA in some viruses
What are the components related to genetic information?
- Chromosome
- Nucleus
- Telomere
In eukaryotes DNA is ___ and in prokaryotes DNA is ____
Linear
Circular
What are the names for DNA in prokaryotes and where are they found?
How is eukaryotic DNA situated and where are they located?
What are plasmids?
Plasmids are small, circular DNA molecules that replicate independently from chromosomal DNA.
Plasmids are commonly found in prokaryotic organisms.
Where are plasmids primarily found?
Plasmids are primarily found in prokaryotes.
Prokaryotes include bacteria and archaea.
What type of genes do plasmids contain?
Plasmids contain genes that may be useful to the prokaryote in specific environments but are not essential for survival.
These genes can provide advantages such as antibiotic resistance.
True or False: Plasmids are essential for the survival of prokaryotes.
False
Plasmids contain non-essential genes that provide advantages in certain conditions.
Fill in the blank: Plasmids replicate independently from _______.
chromosomal DNA
This characteristic allows plasmids to be easily transferred between bacteria.
What are plasmids?
Plasmids are small, circular DNA molecules found in bacteria.
Can plasmids be manipulated in laboratories?
Yes, plasmids can be manipulated in laboratories.
What is a recombinant plasmid?
A recombinant plasmid is formed when a gene of interest is inserted into a plasmid.
How is a recombinant plasmid created?
By removing a plasmid from bacteria and inserting a gene of interest into it.
What happens when a recombinant plasmid is inserted back into bacteria?
The gene will be expressed.
Fill in the blank: When a gene of interest is inserted into a plasmid, it forms _______.
[recombinant plasmid DNA]
True or False: Plasmids can only be found in eukaryotic cells.
False
What are plasmids?
Small, circular DNA molecules found in bacteria
How do bacteria exchange genes?
Through plasmids with neighboring bacteria
What happens after DNA is exchanged between bacteria?
The bacteria can express the genes acquired
What is the significance of plasmids for prokaryotes?
They help with the survival of prokaryotes
What is a key difference between eukaryotic and prokaryotic DNA regarding structure?
Eukaryotic DNA has ends, while prokaryotic DNA is stored as a circular chromosome.
What can happen to the ends of eukaryotic DNA over time?
They can be degraded, leading to gene loss.
What are telomeres?
Caps of long nonsense DNA sequences that protect eukaryotic DNA from degradation.
True or False: Telomeres are found in prokaryotic DNA.
False
This is because in prokaryotes DNA is circular
What is the relationship between telomere loss and aging in eukaryotes?
Telomere loss is speculated to be associated with aging.
What do telomeres do?
They preserve the length of chromosomes
