BIOL 230 Exam 2 PART 2

A segment of DNA that encodes a functional product, usually a protein.

All the genetic information in a cell including chromosome and plasmids .

Most bacteria have a single linear chromosome.

Plasmids replicate independently of the chromosome and often carry genetic information that is not essential but provides the bacterium a selective advantage.

In which direction is a new strand of DNA created?

The DNA backbone is deoxyribose-phosphate (sugar-phosphate).

Relaxes the DNA supercoiling.

Repairs gaps within the backbone of a DNA strand.

Separates the two strands of DNA beginning at the origin of replication.

Creates a complementary copy of DNA off of a template DNA strand.

Creates a complementary RNA molecule off of a DNA template.

DNA is copied by DNA polymerase n the 5' to 3' direction;____________________ is synthesized continuously.

Lagging strand is synthesized ____________________________; Okazaki fragments are joined by DNA ligase.

RNA and DNA contain adenine, guanine and cytosine. DNA contains thymine, but RNA contains _________.

Transcription is the synthesis of a complementary RNA copy of a gene; RNAs are______________stranded molecules.

Transcription is the synthesis of a complementary RNA copy of a gene; ________________a code to make a functional product (protein).

TRNA contains the anti-codon and protein.

Transcription begins when RNA polymerase binds to the DNA _________________sequence.

Transcription proceeds, building a new RNA molecule, in the 5' to 3' direction;Transcription stops when it reaches the DNA promoter sequence.

The start codon is always AUG which codes for MET.

Codons are nucleotides in groups of four.

Sense codons encode for specific amino acids.

Nonsense codons encode for stop codons which stop translation of mRNA strand.

The code for codons is redundant because it is lessens the probability of a base mutation to result in an unfavorable product.

A sense codon encodes for one of the 20 amino acids.

MRNA provides the code (Codons) that are complementary to the copied strand. tRNA brings the attached amino acid with the anti-codon. rRNA is the ribosomal unit that creates the protein in a process called protein synthesis.

The Operon is the sum of____________&_____________________ regions.

Constitutive genes are expressed at a fixed rate (constantly produced).

Induction and repression is accomplished through a repressor protein.

When the repressor protein is first in an activated state then the gene is being suppressed through______________________.

When the repressor protein is first in an inactivated state then the gene is being suppressed through______________________.

Base substitution / point mutation (during DNA replication) a single nucleotide is replaced with a different nucleotide.

Base mutations include:

"A single nucleotide is exchanged for another, but due to the redundant genetic code, there is no change in the protein sequence".

"A single nucleotide is exchanged for another and this results in a single amino acid substitution in the protein sequence".

"A single nucleotide is exchanged for another and this results in the introduction of a premature stop codon".

"One or a few nucleotides are deleted from or inserted into the DNA".

Mutagens _________________ the rate of mutation.

______________________detects mutant cells because they grow or appear different on selective medium. Non mutant cells will not grow.

_________________________detects mutant cells because they do not grow on selective medium.

We want to identify a bacterial colony that has lost the ability to make the amino acid tryptophan (tryptophan auxotroph) how do you achieve that?

"Jumping Genes" are motile genetic material a.k.a. what?

____________________are the simplest transposons; Their ends contain inverted repeats to allow insertion; Contain the gene that codes for transposase, the enzyme that facilitates transfer.

_________________________________carry other genes in addition to an insertion sequence on each end and may carry antibiotic resistance genes.

________________________________ occurs during reproduction between generations of cells (parent to daughter).

____________________________________ is the transfer of genes between cells of the same generation a.k.a. Genetic recombination.

_____________________________________ is when DNA is transferred from one bacterium to another as “naked” DNA.