Download chapter review answers

Name: __________________________________ Per:______
Review questions: Answers will be up on class website!
1. A DNA nucleotide does NOT contain:
a. 5-carbon sugar
b. polymerase
c. a nitrogen base
d. a phosphate group
2. In prokaryotes, DNA is located in the…
a. nucleus
b. cytoplasm
c. ribosome
d. histone
3. The process where DNA makes an exact copy of itself is called…
a. RNA replication
b. Translation
c. Transcription
d. DNA Replication
4. The main enzyme involved in linking DNA nucleotides together is called…
a. tRNA
b. RNA polymerase
c. anticodons
d. DNA polymerase
5. The process by which DNA is copied into a strand of mRNA is called…
a. translation
b.TRANSCRIPTION
c. DNA Replication d. transformation
6. In messenger RNA, each codon specifies a particular
a. nucleotide
b. amino acid
c. purine
d. pyrimidine
7. Changes in the DNA sequence that affect the genetic information are known as
a. replications
b. transformations
c. mutations
c. prokaryotes
8. An expressed gene is one that
a. functions as a promoter
b. is transcribed into RNA
c. codes for only one amino acid
d. is made of mRNA
9. Which of the following is true;
a. RNA is usually single stranded
b. DNA is usually single stranded
c. DNA contains Uracil
d. RNA contains Thymine
10. A promoter is
a. binding site for DNA polymerase
b. binding site for RNA polymerase
c. start signal for replication
d. stop signal for translation
11. Which of the following is a chromosomal mutation
a. inversion
b. point mutation
c. substitution
d. all of the above
Name: __________________________________ Per:______
12. Which of the following is true of gene regulation in eukaryotes
a. promoters determine whether a gene is expressed
b. expressed genes make more DNA
c. RNA polymerase regulates gene expression
d. the TATA box is the stop codon
13. Gene regulation in eukaryotes
a. usually involves operons
b. is simpler than in prokaryotes
c. allows for cell specialization
d. includes the action of an operator region
14. HOX genes determine an animal’s
a. body plan
b. size
c. skin color
d. eye color
15. HOX genes
a. determine when bacteria replicate
b. determine where the flagellum is on the bacteria
c. determine when a dog’s cells replicate
d. determine where a dog’s ears are.
Short answer… Do these questions on another sheet of paper (we’re saving trees here!)
1. What is meant by the term “base-pairing”? How is base pairing involved in DNA
replication?
Bse pairing is the principal that hydrogen bonds only form between certain pairs of bases.
A with T (or U) and G with C. In DNA replication, base pairing ensures that complementary
strands produced are identical to the original strands.
2. Describe the relationship between DNA, histones, chromatin, and nucleosomes.
Nucleosomes are made up of DNA wrapped around histones. Chromatin is long chains of
tightly coiled nucleosomes.
3. Explain the process of replication. When a DNA molecule is replicated, how do the new
molecules relate to the old molecule?
DNA separates into two strands, then produces two new complementary strands following
the rules of base pairing. Each new strand of DNA is an EXACT copy of the original strand.
4. What is the difference between exons and introns?
Introns are sections of mRNA that are removed from the mRNA before it is translated.
Exons are the sections that still remain in the Gene… don’t worry too much about this for
the test,
5. What is a codon? Give an example.
A codon is a set of three nucleotides that codes for a specific amino acid. An example of as
codon is any three letter nucleotide combonation… CAA, GAU, UAG (stop!)
6. What is an anticodon? What role does it play?
An anticodon is a set of complementary bases on transfer RNA that bind to a mRNA to bring
the correct amino acid during polypeptide formation.
Name: __________________________________ Per:______
7. Transcribe and translate the following DNA molecule:
AAATATGGCCCGGAT
mRNA:
UUUAUACCGGGCCUA
Protein:
Phen- Iso - Pro - Gly - Leu
8. Name two major types of mutations. What do they have in common? How are they
different? Give an example of each using the sequence above.
Gene and chromosomal. Both change the DNA sequence and have effects on the genetic
information. Gene mutations involve a change in one or several bases in DNA whereas
chromosomal mutations involve changes in number or structure of whole chromosomes.
9. Describe how the TATA box helps to position RNA polymerase.
The TATA box (and promoters!) help the RNA polymerase find the spot just before where a
gene starts and transcription begins.
10. Describe the processes of transcription and translation in words, specifying where each
takes place and why.
Transcription involves RNA polymerase binding to the promoter and TATA box in
eukaryotes. The RNA polymerase then moves down the DNA strand and starts to add
nucleotides of mRNA to the complementary bases of DNA. When the stop signal is reached,
the mRNA leaves the DNA, DNA “rezips,” and remains in the nucleus. The mRNA leaves the
nucleus and finds a ribosome in the cytoplasm. At the start codon (AUG) the first tRNA
binds to the codon on mRNA. The second tRNA binds next to the first. The first tRNA
transfers its amino acid to the second and leaves. The process continues like this until the
“stop” codon is reached. Then the finished polypeptide, ribosome, and mRNA detach.
Both involve initiation, elongation, and termination.
11. Describe one situation where a mutation would be bad for the protein created. Use an
example to illustrate.
If a mutation (point mutation) changed the last letter of a codon and made it into a STOP
codon, the protein will not be formed completely (UGU to UGA). Frame shift mutations also
cause a change in the entire structure of the protein that was supposed to be made.
Process
Definition
Location
Function
Enzyme/molecule(s)
involved
Replication
Making an
exact copy of
the DNA
within a cell
Nucleus
Making exact
copies of DNA
DNA polymerase,
ligase, Helicase
others
Transcription
DNA used to
make mRNA
Nucleus
Make a copy of
the DNA code
so that the
code can be
used to build
proteins
RNA polymerase
Translation
Using the RNA
codons; switch
language of
Ribosome/
cytoplasm
Build a
polypeptide or
Not discussed: but
handout mentions
Name: __________________________________ Per:______
bases to a.a
protein
peptidyl transferase