Exam 4 Flashcards
What is a Genome?
The complete set of an organism’s DNA, including all of its genes.
Define Chromosome.
A thread-like structure made of DNA and proteins that contains genes.
What is a Gene?
A segment of DNA that codes for a specific protein.
What is a Codon?
A sequence of three nucleotides in mRNA that specifies an amino acid.
What does Locus refer to?
The specific physical location of a gene on a chromosome.
What is Gene Expression?
The process of using a gene’s instructions to make a protein.
What is a GMO?
An organism whose genome has been altered by humans.
Define Transgenic Organism.
An organism that contains DNA from another species.
What is a Recombinant Gene?
A DNA molecule made by combining DNA from different sources.
Who won the Nobel Prize in 1962 for discovering the double-helix structure of DNA?
James Watson, Francis Crick, and Maurice Wilkins.
Where is DNA located in Eukaryotic Cells?
In the nucleus.
What type of bonding occurs between complementary base pairs in DNA?
Hydrogen bonding.
List the four nucleotide bases in DNA.
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
During which phase of the cell cycle does DNA replication occur?
S phase.
What enzyme unzips the DNA during replication?
Helicase.
What enzyme adds new nucleotides during DNA replication?
DNA polymerase.
What is meant by semi-conservative replication?
Each new DNA molecule has one old strand and one new strand.
Why do cells replicate DNA?
To ensure each new cell has an exact copy of the DNA.
What are the two main processes involved in DNA fingerprinting?
- PCR (Polymerase Chain Reaction)
- Gel Electrophoresis
What was the goal of the Human Genome Project?
To map all human genes.
How many genes do humans have approximately?
~20,000.
What are the main differences between DNA and RNA?
- DNA has thymine (T), RNA has uracil (U)
- DNA is double-stranded, RNA is single-stranded
- DNA has deoxyribose, RNA has ribose sugar
List the three types of RNA.
- mRNA
- tRNA
- rRNA
What is the flow of genetic information?
DNA → RNA → Protein.
What does RNA processing involve?
- Adding a cap and tail
- Splicing: Remove introns, keep exons
What is a Point Mutation?
One base is changed.
What is a Silent Mutation?
No effect on protein.
What is a Frameshift Mutation?
Insertion/deletion that shifts the reading frame.
What is Recombinant DNA?
DNA from different sources combined into one molecule.
Why create a Transgenic Organism?
To give an organism beneficial traits from another species.
How is E. coli used for human proteins?
Human gene is inserted into plasmid, then into E. coli.
What are the two parts of a gene?
- Regulatory sequence
- Coding sequence
What are Embryonic Stem Cells?
Can become any cell type; require destruction of embryos.
What is Reproductive Cloning?
Creates a whole organism.
Who was the first cloned mammal?
Dolly the sheep, cloned in 1996.
The regulation of gene expression ensures that
Not all genes are expressed at all times
Because stem cells are cloned from the body’s own tissues in therapeutic cloning , the body’s immune system
Accepts the implanted cells
Although the number of genes in the human gene is surprisingly low alternative splicing blank allows the G ends in code 4 times as many proteins
Exons
Econ’s
