QUESTIONS AND CORRECT SOLUTIONS
The structure of a strand of DNA. - Correct answer-it is a double helix, like a
twisted ladder.
the ladder rings are nucleotide subunits and they have a covalent bond to the
sugar phosphate backbone (made of deoxyribose and a phosphate group)
What are the nucleotide subunits? - Correct answer-adenine, guanine, cytosine,
and thymine
How are the subunits held together? - Correct answer-through a hydrogen
bond
What are the nucleotide subunits compliments? - Correct answer-Adenine and
thymine
cytosine and guanine
How does DNA replicate? - Correct answer-the parent strand breaks off into
two and then enzymes (DNA polymerases) attach the complimentary
nucleotide to each side, creating two separate daughter strands
What is the location site of where DNA replication begins on the double helix
called? - Correct answer-the origins of replication
What is created when replication proceeds in both directions? - Correct
,answer-replication bubbles, they are created because at the origin the
replication process proceeds in other directions, creating a bubble.
What is the replication forks? - Correct answer-It is the location where the
parent cells is separating and the complimentary nucleotide is being added
creating the two new strands
How does DNA determine specific traits (phenotypes)? - Correct answer-
Phenotypes arise from the actions of a wide variety of proteins. To get these
proteins this is what happens. DNA transfers genetic information through
transcription to RNA. Then through translation genetic info is transferred
from RNA into a polypeptide (protein strand)
What is the structure of RNA? - Correct answer-It is a single-stranded nucleic
acid.
it is the same as DNA except it uses ribose instead of deoxyribose in the sugar
phosphate backbone and it uses uracil instead of thymine
tRNA - Correct answer-transfer RNA: translation of the genetic message
carried in the mRNA into the amino acid language of proteins (converts the
three-letter words, codons, of nucleic acids to the amino acid words of
proteins)
What is the function of mRNA? - Correct answer-Messenger molecules carry
the coding sequences for protein synthesis and are called transcripts.
rRNA - Correct answer-ribsosomal RNA
makes up ribosomes which are the organelles in the cytoplasm that coordinate
, the functioning of mRNA and tRNA and actually make polypeptides
What two processes do genes code for specific proteins? - Correct answer-
transcription and translation
What is transcription and where does it take place? - Correct answer-
Transcription is the synthesis of mRNA under the direction of DNA, nucleus
What is translation and where does it take place? - Correct answer-It is the
synthesis of a polypeptide (later becomes a protein) under the direction of
mRNA
occurs on ribosomes in the cytoplasm
What is the structure of tRNA? - Correct answer-It is made of a single strand
of RNA. consisting of about 80 nucleotides. Chain twists and folds upon itself,
forming several double-stranded regions in which short stretches of RNA
base-pair with other stretches. one end has a special triplet of bases called
anticodons. it is complementary to a codon triplet on mRNA. on the other side
there is an amino acid attachment site.
What is a mutation? - Correct answer-It is a change in the genetic material (the
nucleotide sequence) of a cell's DNA.
What is a point mutation? - Correct answer-It is a change in once base pair of a
gene.
What is a plasmid? - Correct answer-A small ring of self-replicating DNA
separate from the larger chromosomes. Plasmids are most frequently derived