Biology Quiz 8

What on DNA allows the bases to break for strand seperation

the hydrogen bonds

Who found this model of DNA?

Watson, crick, and Rosalind Franklin

Which model states that the two strands of the original molecule servers as a template for the two strands of a new DNA molecule that rewind into an all old molecule

conservative replication model

which model states that both strands of the replicated molecule contains old and new segments

dispersive replication model

What did the meslson and stahl experiment find?

replication was semi conservative

What did meselson and stahl do for their experiment in 1958

they grew bacterial cells in heavy nitrogen, put it in light nitrogen, then extracted dna at various intervals and seperated the molecules using a centrifuge

What year was the meselson and stahl experiment done

1958

What is responsible for assembling complementary polynucleotide chains from individual deoxyribonucleotides

DNA polymerase

What are the 4 different deoxyribonucleotide triphosphates

dATP, dGTP, dCTP, dTTP

Which end of dna does dna polymerase add the nucleotide

3’ end

DNA polymerase only assemble nucleotide chains in the ___ Direction

5’-3’

Why is the dna strand read in 3’-5’ direction if its assembled in the 5’-3’ direction

The DNA strands run antiparallel to another

What are the 3 requirements for dna replication

parental dna, enzymes, nucleotide triphosphates

What is the protein that encircles the dna and attaches to the real of the polymerase to tether the dna polymerase to the template strand and make the rate of synthesis faster

sliding DNA clamp

A DNA strand begins with a short chain of RNA synthesized by the enzyme ___

primase

In the bacterial chromosome, what unwinds the dna strands and produces a y shaped replication fork

dna helicase

In the bacterial chromosome, what coats the exposed single stranded dna segments to prevent pairing

Single stranded binding proteins

What in the bacterial chromosome cuts and rejoins dna to prevent twisting

topoisomerase

Which is synthesized in the direction of dna winding

leading strand

which is synthesized discontinuously in the direction opposite of dna unwiding

lagging strand

what are the fragments of dna caused by discontinuous synthesis and are 100-200 base pairs long

okazaki fragments

What are the structures in eukaryotic chromosomes that protects the ends of chromosomes from nucleases and maintains integrity of linear chromosomes

telomeres

In each round of cell division, why is there gradual shortening of chromosomes

the last section of lagging strand is unable to be replicated because of the rna primer

What stops the shortening of telomeres by adding telomere repeats to chromosoe ends

telomerase

What are some problems with the lagging strand

telomerase makes telomere of lagging strand use internal rna template, telomerase can cause aging and cancer

Any agent that increases the number of mutations above background level is called a

mutagen

What allows the dna polymerase to back up and remove mispaired nucleotides

proofreading mechanism

what does the dna polymerase use to remove the newly added incorrect nucleotide

3’-5’ exonuclease

what seals the nuceotide chain after dna polymerase fills the repair gap with new dna

dna ligase

what mechanism repairs nonbulky damage by removing the erroneous base and replacing it with the correct one based on complementary pairing rules

base excision repair

what name did francis crick give to the flow of information from dna to rna to protein

central dogma

what is the mechanism by which information encoded in the dna remplate strand is copied into a complementary rna strand

transcription

what uses the information encoded in the RNA copy to assemble amino acids into a polypeptide

translation

What type of mRNA must be altered to generate the functional mRNA after being prescribed in the nucleus

precursor-mRNA

what is the nucleotide information that specifies the amino acid sequence of a polypeptide

genetic code

what is the 3 letter word of code in dna

codon

who identified the codons that specify each amino acid, and stop/start codons

marchall nirenberg

if some amino acids are specified by more than one codon, the code is referred to as

degenerate

Which codon is the start codon

AUG

Which codons are used to terminate translation

UAA, UGA, UAG

because genetic code has no indicator to mark the end of one codon and the beginning of the next

commaless

what is the science that includes any technique applied to a biological systems or living organisms to make or modify products or processes for a specific purpose

biotechnology

what are examples of biotechnology

beer brewing, yogurt and cheese production, genomics, bioinformatic tools

any organism that has its genome altered to change a genetic trait or traits is called a

genetically altered organism

what are dna fragments from two or more different sources that have joined together to form a single molecule

recombinant dna