Biology test
Observe the amino acid sequence below. Before: METHIONINE - VALINE - PROLINE - LYSINE - LEUCINE After: METHIONINE - VALINE - PROLINE - LYSINE - SERINE - LEUCINE Which type of mutation is shown above?
Insertion
What type of mutation is shown in sequence C?
Insertion
What is the function of transfer RNA?
It delivers the correct amino acid to the ribosome.
What is the significance of the sequence of nucleotides?
It determines the type of protein being produced
How would overexposure to X-rays affect most animal cells?
It would change the sequence of DNA nucleotides in affected cells.
Which polypeptide would be produced from the DNA segment TAC GAT CTA CGA?
Methionine - Leucine - Aspartate - Alanine
Which shows the translated amino acid chain for the code AUG GCC UAC?
Methionine, Alanine, Tyrosine
Which is a change in DNA which can result in a change in amino acid sequence, protein function, or phenotype?
Mutation
In which part of the cell does the initial process of transcription take place?
Nucleus
What two organelles are involved in protein synthesis?
Nucleus and ribosome
Which of these is most likely to cause some form of mutation?
Smoking cigarettes
Why is it important for DNA to be duplicated exactly before a cell divides?
So genetic information is correctly passed on to govern the cellular processes in the new daughter cells.
Which type of mutation is shown in the following DNA sequence?
Substitution
Which DNA strands would produce the amino acid sequence below? Isoleucine Tyrosine Histidine
TAA ATG GTA
A small portion of a normal DNA gene sequence that codes for a particular protein has the following bases: TCG ATG CCA. Which mutated sequences would most likely have serious consequences in protein function?
TAC GAT GCA A
A strand of DNA has these bases: AGC CAT GTA TAC What is the complementary DNA strand?
TCG GTA CAT ATG
Which is the greatest consequence of transcription being blocked in the nucleus?
The DNA would not be copied into RNA.
What would happen to an organism if DNA did not replicate itself?
The organism would not be able to grow or reproduce.
Plants with red flowers are exposed to a high level of radiation. The next week, buds on these plants open to reveal white flowers. What has happened?
The radiation caused a mutation, resulting in the plant being unable to make red pigment.
A mutation in a strand of mRNA results in a premature stop codon in the middle of the sequence. Which best describes the result of this type of mutation?
The resulting protein translated from this sequence will be too short and will not function properly.
Which is an accurate description of how DNA is replicated?
The two strands of DNA are "unzipped" and each serves as a template for a complementary DNA strand.
Which best describes the role of the free floating nucleotides (A, C, G, and T) in the illustration?
They are the building blocks that are used to make the new strands.
Which is true of hydrogen bonds in the DNA molecule?
They are weak so that the strand can be easily broken for replication.
Which is the process of DNA coding into mRNA?
Transcription
What is the relationship between transcription and translation?
Transcription produces the message that translation uses to make a protein.
How are the amino acids linked together during translation?
by creating peptide bonds
The DNA nucleotide is composed of three parts. Which two components make up the nucleotide backbone?
deoxyribose sugar and phosphate group
What is the most likely outcome from DNA mutation of an organism?
different proteins assembled
Which best describes the shape of a DNA molecule?
double helix
Which amino acids are coded for by an mRNA segment that reads CAG GUG?
glutamine to valine
Which best describes the role of mRNA in protein synthesis?
mRNA brings the code of DNA to the ribosome where it is used to construct a protein.
Which most closely matches the goal of protein synthesis?
making a protein
During transcription, the genetic information for making a protein is rewritten. Which molecule is formed during transcription?
messenger RNA
What are the subunits of DNA and RNA?
nucleotides
Which human genetic disorder is the result of a DNA mutation that causes a change in one amino acid in the sequence for the protein hemoglobin?
sickle-cell anemia
Which mutation in DNA affects only one nucleotide in a sequence?
substitution
A molecule is observed traveling to the ribosome where it undergoes a change by releasing an attached subunit. Which may best describe this molecule?
tRNA
Which occur during protein synthesis?
transcription and translation
Which is a way that RNA differs from DNA?
uracil base
If a segment of DNA is made up of 40% thymine, how much guanine is present?
10%
Tobacco contains chemicals known as carcinogens. What do these chemicals do?
Cause cancer
What type of mutation occurs when a piece of a chromosome is lost during cell division?
Deletion
What type of mutation results when a nucleotide is missing from a DNA strand?
Deletion
Some of the existing genes of an organism mutated randomly. Below shows the DNA sequence before and after. Before: A T C G U T A T A G G A C T C After: A T C G U T A G G A C T C What will most likely be the result of the above mutation?
Different proteins than before will be produced.
What does the replication of DNA during interphase ensure during cell replication?
Each daughter cell gets an exact copy of the cell's DNA.
Which is true of the DNA produced by replication?
Each new molecule is half new DNA and half original DNA.
Which type of bond, denoted by the arrows, allows DNA to be readily replicated?
Hydrogen bonds
Which best represents the sequence of bases on mRNA?
A U C G
During DNA replication, a mutation occurred and changed the base sequence below. ACT GCT TGA CGA to ACT GCT TAC GA
A deletion
Which complementary base sequence can be produced during DNA replication?
ATA GGG CTA
In complementary DNA strands, which bases pair together?
Adenine and thymine; guanine and cytosine
Proteins are composed of polypeptide chains. What are polypeptide chains composed of?
Amino acids
Which is an example of a genetic mutation?
An extra nucleotide is added during DNA replication.
A segment of DNA has the base sequence: TGA GAC TGC AGC A mutation occurs during replication and produces the sequence: TGAGACATGCAGC Which mutation has most likely occurred?
An insertion
A segment of DNA has this sequence: ATA GCA CAT GTA What is the mRNA sequence transcribed from this segment?
UAU CGU GUA CAU
Which type of environmental interaction, through repeated exposure, can cause a functional change in the skin cells?
UV radiation
Which best describes a mutation induced by radiation?
a change in DNA sequence
Which are the basic units of a DNA nucleotide?
a single nitrogen base, a sugar, and a phosphate
DNA is a spiral ladder-shaped structure with the sides of the ladder representing which components?
alternating sugars and phosphates
What results from the triplet code of DNA?
amino acid