Unit 6 - Molecular Genetics

DNA sequence

The \________ of a homeotic gene that tells the cell where to put things is called the homeobox.

RNA polymerase

\________ is then free to bind to that site and initiate transcription of the genes.

Telomeres

\________- specialized structures composed of short repeated sequences of DNA that are made by telomerase.

Primase

\________ binds to the primer, and DNA polymerase, the superstar enzyme of this process, attaches to the primer region and adds nucleotides to the growing DNA chain in a 5′- to- 3′ direction.

Inducer

\________: a molecule that binds to and inactivates a repressor (e.g., lactose for the lac operon)

Electrophoresis

\________ separates DNA samples from the suspect and whatever sample is found at the scene of the crime.

Wobble

\________- a uracil in the third position of an anticodon can pair with A or G instead of just A.

MRNA

\________ is produced on a DNA template and is read in bunches of three- codons, which tell the protein synthesis machinery which amino acid to add to the growing protein chain.

mRNA molecule

A(n) \________ is divided into a series of codons that make up the code.

Ligase

\________: enzyme that connects two strands of DNA together by forming a bond between the phosphate group of one strand and the deoxyribose group of another.

Retroviru

\________- an RNA virus that carries an enzyme called reverse transcriptase.

DNA

In bacteria, mRNA- ready immediately after it is released from the \________.

PCR

\________ is used in many ways, such as to detect the presence of viruses like HIV in cells, diagnose genetic disorders, and amplify trace amounts of DNA found at crime scenes.

parasitic infectious agent

Virus a(n) \________ that is unable to survive outside of a host organism.

Phage

\________- a virus that infects bacteria.

Helicase

\________- enzyme- unzips the DNA, breaking the hydrogen bonds between the nucleotides and producing the replication fork.

DNA of interest

The plasmid and \________ are both cut with the same restriction enzyme.

Plasmids

\________ used for cloning often contain two important genes- one that provides resistance to an antibiotic, and one that gives the bacteria the ability to metabolize some sugar.

virus

Once a(n) \________ infects a cell, it takes over the cells machinery and uses it to produce whatever it needs to survive and reproduce.

inosine

There are some tRNA molecules that have an altered form of adenine, called \________ (I), in the third position of the anticodon.

promoter region

In the absence of lactose, a repressor binds to the \________ and prevents transcription from occurring.

UAG

The stop codons are UAA, \________, and UGA.

central dogma

The \________- coined by Francis Crick in 1957 to describe the flow of genetic information through a biological system.

Mutation

\________- a heritable change in the genes of an organism.

Vector

\________- moves DNA from one source to another.

Transformation

\________ occurs through the use of proteins on the surface of cells that snag pieces of DNA from around the cell that are from closely related species.

construction of proteins

MRNA- escaped from the nucleus- it is ready to help direct the \________.

Deletion

\________ or addition of DNA nucleotides that does not add or remove a multiple of three nucleotides.

Viruses

\________ do not contain enzymes for metabolism, and they do not contain ribosomes for protein synthesis.

genetic material

Capsid a protein shell that surrounds the \________.

Transcription

\________- consists of three steps: initiation, elongation, and termination.

Translocation

\________- the ribosome moves along the mRNA in such a way that the A site becomes the P site and the next tRNA comes into the new A site carrying the next amino acid.

eukaryotes

In \________- the mRNA produced after transcription must be modified before it can leave the nucleus and lead the formation of proteins on the ribosomes.

Enhancer

\________: DNA region, also known as a "regulator, "that is located thousands of bases away from the promoter; it influences transcription by interacting with specific transcription factors.

Operator

\________: a short sequence near the promoter that assists in transcription by interacting with regulatory proteins (transcription factors)

Sickle cell anemia

\________ represents a prime example of a point mutation leading to a phenotypic change in humans.

multiple genes

Operon: a promoter /operator pair that services \________; the lac operon is a well- known example.

Cells

\________ containing different organelles or other cytoplasmic components are able to perform different functions.

Point mutations

\________, which alter a single base, can be a substitution of another base, a deletion of a base (s) or an addition of a base (s)

Lysogenic cycle

\________, the virus falls dormant and incorporates its DNA into the host DNA as an entity- provirus.

DNA polymerase

\________ is restricted in that it can only add nucleotides to the 3′ end of a parent strand.

notochord region

The cells from the \________ act as "project directors, "telling the ectoderm where to produce the neural tube and central nervous system.

eukaryotic chromosomes

In \________, DNA replication- issue for the structure of the chromosome.

Southern blotting

It can be used in a procedure known as \________ to determine if a particular sequence of nucleotides is present in a sample of DNA.

Histone modification

\________ affects chromatin structure* DNA in eukaryotes is organized first into nucleosomes and then into higher- order chromatin structures.

Ribosomes

\________- made up of a large and a small subunit.

histones

The \________ that make up the nucleosome core have amino tails that protrude.