Download Unit 4 ~ DNA Review

UNIT 4 ~ DNA REVIEW
UNIT 4 ~ DNA REVIEW
DNA: Deoxyribonucleic Acid
Found:
in the nucleus of Eukaryote cells
RNA: Ribonucleic Acid
Made:
 in the Nucleus and brings message to
Ribosomes
UNIT 4 ~ DNA REVIEW
Shape:
Double Helix
Repeating nucleotides
 Nucleotide: 1 Base, 1
Sugar, & 1 Phosphate
UNIT 4 ~ DNA REVIEW
1953: Who established the structure of
DNA?
James Watson & Francis Crick
Rosalind Franklins work helped ^
UNIT 4 ~ DNA REVIEW
Gene - a segment of ______ that
codes for a protein, which in turn codes
for a trait (skin tone, eye color, etc…)
Example:
TGCCAGTCA
THE BASES
The organic bases are
Adenine
(A)
Thymine
(T)
Cytosine
(C)
Guanine
(G)
Nucleotides pair in a
specific way - called the
Base-Pair Rule
T
A
G
C
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JOINED
NUCLEOTIDES
PO4
A molecule of
DNA is formed by
millions of
nucleotides joined
together in a long
chain
PO4
PO4
PO4
sugar-phosphate
backbone
+ bases
BONDING 2
PO4
PO4
adenine
thymine
PO4
PO4
cytosine
guanine
PO4
PO4
PO4
PO4
DNA replication is semi- _____________.
That means that when it makes a copy, one half
of the old strand is always kept in the new
strand. This helps reduce the number of copy
error
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UNIT 4 ~ DNA REVIEW
Mutations occur at some time during a
person's life and are present only in certain
cells, not in every cell in the body.
This can occur if a mistake is made as DNA
copies itself during cell division. OR can be
caused by environmental factors such as
ultraviolet radiation from the sun.
RNA
 DNA remains in the _______________ but in order for it
to get its instructions translated into proteins, it must send
its message to the ribosomes, where proteins are made. The
chemical used to carry this message is Messenger RNA
 RNA = ribonucleic acid.
 RNA is similar to DNA except:
 1. has one strand instead of two strands.
2. has uracil instead of thymine
3. has ribose instead of deoxyribose
 mRNA has the job of taking the message from the DNA to
the nucleus to the ribosomes.
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UNIT 4 ~ DNA REVIEW
Transcription: The code is read by copying
stretches of _____into the related nucleic
acid _____
Translation: Proteins are made from the
message on the ______
UNIT 4 ~ DNA REVIEW
REVIEW QUESTION #1
Which of the following describes the function of
DNA?
A. storing energy in chemical bonds
B. encoding genetic information
C. speeding up biochemical reactions
D. destroying substances that enter the cell
REVIEW QUESTION #2
Which of the following units are repeatedly
joined together to form a strand of DNA?
A. amino acids
B. fatty acids
C. nucleotides
D. polysaccharides
REVIEW QUESTION #3
During the process of replication, a molecule of DNA unzips,
forming two single strands.
What makes up each individual strand of DNA?
A. paired adenine and uracil bases
B. paired thymine and guanine bases
C. sugar groups attached to individual amino acids
D. bases attached to a sugar-phosphate backbone
REVIEW QUESTION #4
In a sample of double-stranded DNA, 30% of the
nitrogenous bases are thymine. What percentage of
the nitrogenous bases in the sample are adenine?
A. 20%
B. 30%
C. 60%
D. 70%
REVIEW QUESTION #5
Which of the following statements explains why the insertion of a nucleotide in a
DNA sequence could result in a physical change in an organism?
A. Fatty acids would no longer attach to the DNA strands to transcribe the
DNA.
B. The DNA would no longer fit through the nuclear membrane to get to
ribosomes for translation.
C. The sequence of nitrogenous bases in the DNA would no longer code for
the correct amino acids.
D. Antibodies would no longer recognize the DNA as belonging to the cell and
would destroy the DNA.
REVIEW QUESTION #6
An RNA sequence is shown below.
AUGCCGAAACGU
Which of the following statements describes how the RNA sequence
specifies the production of an amino acid chain?
A. Each individual RNA base codes for a single amino acid.
B. Each group of three RNA bases codes for a single amino acid.
C. Each group of three RNA bases codes for an enzyme that helps join
amino acids together.
D. Each individual RNA base codes for the ribosome location where
amino acids are assembled.
REVIEW QUESTION #7
During the process of replication, a molecule of DNA unzips,
forming two single strands. What makes up each individual
strand of DNA?
A. paired adenine and uracil bases
B. paired thymine and guanine bases
C. sugar groups attached to individual amino acids
D. bases attached to a sugar-phosphate backbone
REVIEW QUESTION #8
The diagram represents the expression of the genetic code in organisms.
Three parts of the diagram are labeled X,Y, and Z.
What do X,Y, and Z represent in the diagram?
A. X is replication,Y is a gene, and Z is mutation.
B. X is crossing over,Y is DNA, and Z is mitosis.
C. X is transcription,Y is mRNA, and Z is translation.
D. X is meiosis,Y is a chromosome, and Z is transport.
REVIEW QUESTION #9
A DNA sequence is shown below.
TAGGAGCAT
What is produced when the sequence is transcribed?
A. a chain of three amino acids
B. a set of three tRNA molecules
C. a section of DNA with the base sequence ATCCTCGTA
D. a section of mRNA with the base sequence AUCCUCGUA
REVIEW QUESTION #10
The diagram below represents a small section of a DNA
molecule.
Which section of DNA represents the complementary strand
to the section of DNA above?
A. A T T C G G G A T A T T
B. T T A T A G G G C T T A
C. T A A G C C C T A T A A
D. A A T A T C C C G A A T
REVIEW QUESTION #11
A sample of human DNA contains approximately 30%
adenine and 20% guanine. Based on DNA structure,
what are the expected percentages of the other bases
in the sample?
A. 10% thymine, 40% cytosine
B. 20% thymine, 30% cytosine
C. 30% thymine, 20% cytosine
D. 40% thymine, 10% cytosine
REVIEW QUESTION #12
A mutation occurs in an individual, but the individual’s outward
appearance does not change. Which of the following statements
describes what most likely occurred to produce this result?
A. The mutation deleted a portion of a coding section of the DNA.
B. The mutation caused a portion of a coding section of the DNA
to repeat.
C. The mutation affected a nucleotide in the DNA, but the
mutation did not affect the sequence of amino acids synthesized.
D. The mutation translocated a group of nucleotides in the DNA,
but the mutation did not change the number of base pairs in the
DNA.
REVIEW QUESTION #13
A mutation occurs in an individual, but the individual’s outward
appearance does not change. Which of the following statements
describes what most likely occurred to produce this result?
A. The mutation deleted a portion of a coding section of the DNA.
B. The mutation caused a portion of a coding section of the DNA
to repeat.
C. The mutation affected a nucleotide in the DNA, but the
mutation did not affect the sequence of amino acids synthesized.
D. The mutation translocated a group of nucleotides in the DNA,
but the mutation did not change the number of base pairs in the
DNA.
REVIEW QUESTION #14
The diagram represents a process that occurs in the nucleus of a
eukaryotic cell.
Which of the following statements describes what is happening in
this process?
A. Molecules of RNA are forming chromosomes.
B. A molecule of mRNA is directing the production of tRNA.
C. Molecules of DNA are being packaged for export to the
ribosomes.
D. A molecule of DNA is being replicated to make two identical
copies.
REVIEW QUESTION #15
Which of the following features of DNA is most important in
determining the traits of an organism?
A. the direction of the helical twist
B. the number of deoxyribose sugars
C. the sequence of nitrogenous bases
D. the strength of the hydrogen bonds
REVIEW QUESTION #16
The table presents a variety of
mRNA three-base sequences
(codons) and the amino acids for
which these sequences code.
Based on the information in the
table, which of the following
changes is least likely to produce a
phenotypic change in an organism?
A. GAU to GGU
B. GAU to GUU
C. GAU to GAC
D. GAU to GAA
1st Base
of
mRNA
2nd base
of
mRNA
3rd base
of
mRNA
Amino Acid
G
A
A
Glutamic acid
C
Aspartic acid
G
Glutamic acid
U
Aspartic acid
A
Glycine
C
Glycine
G
Glycine
U
Glycine
A
Valine
C
Valine
G
Valine
U
Valine
G
U