Download Chapter 12 Study Guide Answer Key.notebook

Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
Study Guide Chapter 12
1. Know ALL of your vocabulary words!
2. Name the following scientists with their contributions to Discovering DNA:
a. Strains can be transformed (or changed) into other forms while studying bacteria that cause pneumonia. Discovered transforming factor could change bacteria into other forms of bacteria.
Griffith
b. Identified the specific molecule that transformed the rough strain of bacteria into a smooth strand of bacteria. Discovered that DNA is the transforming factor.
Avery
c. Used radioactive labeling when studying viruses and bacteria and discovered that DNA is the genetic material in a virus and not protein.
Hershey and Chase
d. Discovered the structure of DNA as being a double helix molecule.
Watson and Crick
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
3. Compare/contrast DNA and RNA in the following table:
DNA
Name
Deoxyribonucleic acid
Macromolecule
Type
Structure (single or double)
Building Blocks
Name of Sugar Phosphate? (Yes or No)
4 Nitrogen Bases
RNA
ribonucleic acid
nucleic acid
nucleic acid
double
single
nucleotides
nucleotides
deoxyribose
ribose
yes
yes
A T C G
Leave Nucleus? (Yes or No)
No
A U C G
Yes
4. What 3 organelles contain DNA?
nucleus, mitochondria and chloroplast
5. Explain why the structure of DNA is referred to as a double helix molecule.
Two twisted strands connected
like a spiral staircase
6. Draw the basic structure of a nucleotide and label the parts (phosphate group, sugar, nitrogen base).
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
7. How and where are phosphate and sugar arranged on the DNA molecule?
They alternate along the outside edges (rails) of the DNA
8. Where are the nitrogen bases found on the DNA molecule?
they are paired in the middle (complementary)
9. What is meant by semiconservative replication?
the old DNA separates, serves as a template, and then
becomes part of the new DNA
10. Semiconservative replication is the process of copying DNA. Explain the 3 steps of this process.
a. Step 1: Unwind and unzip the DNA
______________________________________________________________________
·
What enzyme unwinds and unzips the DNA into two separate strands?
DNA helicase
·
What happens to the hydrogen bonds between base pairs?
The bonds are broken
·
Which molecule is responsible for keeping the DNA strands open and separate?
single strand binding proteins
·
What enzyme adds short segments of primer on each DNA strand?
Primase
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
b. Step 2: Add new base pairs
_________________________________________________________________________
·
What is the function of the enzyme DNA polymerase?
add the new nucleotides to make the new DNA
·
(T/F) The two new strands of DNA are being produced in the same way.
1. The (leading, lagging) strand adds new nucleotides in a smooth, continuous motion.
2. The (leading, lagging) strand adds new nucleotides in small chunks called Okazaki Fragments and the motion is discontinuous.
« What enzyme is responsible for adding more bases to fill in the gaps to make a continuous DNA strand?
DNA ligase
c. Step 3: Joining the base pairs
_________________________________________________________________
DNA polymerase
· __________________________________________ removes primer and fills in the place with nucleotides.
DNA ligase
· __________________________________________ joins the sections to make each strand continuous.
· How many new strands of DNA are produced at the end of replication?
2
· (T/F) Each new strand of DNA produced is made up of ½ old DNA and ½ New DNA.
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
11. Compare and contrast DNA replication in Prokaryotes and Eukaryotes.
Prokaryotes
• DNA is shorter;
• DNA is in a
circular shape;
• DNA replicates
one section at a
time
Eukaryotes
BOTH
• DNA is longer;
• DNA replicates many
sections at a time
replicate in
two directions
12. According to the Base­Pair Rule, what nitrogen bases pair together ALWAYS:
DNA
RNA
Adenine and Uracil
Guanine and Cytosine
Adenine and Thymine
Guanine and Cytosine
13. Which nitrogen bases are: Purines? A and G
Pyrimidines?
T C and U
14. (T/F) Purines always bind to pyrimidines.
15. How many hydrogen bonds between adenine and thymine (or uracil)?
2 (double bond)
16. How many hydrogen bonds between guanine and cytosine?
3 (triple bond)
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
17. (T/F) The two sides of DNA are oriented in opposite directions called anti­parallel.
18. Explain how the DNA molecule (as long as it is) fits into a very small, microscopic cell.
DNA coils around histones (proteins) to form chromatin.
Chromatin coils to form nucleosomes.
Nucleosomes supercoil and form X-shaped chromosomes
19. Why is DNA called the “code of life” or the “genetic code”? (Hint: What does it code for that is so important?)
It codes for all of the proteins an organism
needs to survive
20. Why are proteins important? Which 2 cell organelles synthesize proteins?
Proteins determine how an organism looks and functions.
Ribosomes and the Rough ER synthesize proteins
21. A segment of DNA that contains instructions for making a protein is called a
gene
_______________________________.
22. (T/F) A gene is a specific location on a chromosome and controls inherited trait expression when passed on for generations.
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
23. Name and describe the functions of the 3 types of RNA.
mRNA - messenger RNA
the complementary strand to DNA. Carries the "recipe" to
the ribosome
rRNA - ribosomal RNA
forms the structure of the ribosome
tRNA - transfer RNA
transports amino acids to the ribosome
24. Explain the process of transcription.
a. Occurs in the nucleus
protein
b. A gene for a specific _____________________________________________ mRNA
is turned on and copied from DNA into ________________________.
c. As DNA strand unwinds and unzips the enzyme RNA polymerase
____________________________________ regulates RNA synthesis.
d. What happens to the newly synthesized mRNA strand and where does it go?
it detaches from the DNA and migrates out of the nucleus
into the cytoplasm.
rejoin
e. Two DNA strands _____________________________.
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
25. How is DNA different among organisms?
the sequence of bases is different
26. How many amino acids are used to make proteins?
there are 20 total amino acids
codon
27. 3 base code of nitrogen bases is called a ___________________________.
28. (T/F) 1 codon codes for 1 amino acid.
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
29. Explain the process of translation.
cytoplasm
a. Occurs in the _______________________________.
b. Interprets genetic information from ______________________ and builds a mRNA
protein
___________________________.
c. What attaches to a ribosome and how is it read?
mRNA attaches. It is read 3 bases at a time (codons)
d. What does tRNA carry and drop off to the ribosome?
amino acids
·
How many different types of tRNA molecules exist? 20
·
The end of the tRNA molecule where 3 complementary bases attach is anti-codon
called the _____________________.
amino acid
· The other end of the tRNA molecule is where an __________________ attaches.
e. What type of bond forms between amino acids? peptide bonds
f. What happens once the stop codon is reached?
synthesis ends and the protein leaves the ribosome
30. The ability of an organism to control which genes are transcribed is called _________________________________.
gene regulation
31. What is a mutation?
permanent change in the DNA
32. (T/F) Mutations can affect a single gene or an entire group of genes
33. If a [gamete (sex cell), body cell (somatic)] becomes mutated, the mutation will be passed to offspring
34. If a [gamete (sex cell), body cell (somatic)] becomes mutated, the mutation will not be passed to offspring.
point
35. A chemical change in one base pair is called ___________________________ mutation.
a. Name and explain the 2 types of point mutation.
missense = wrong amino acid will be added
nonsense = an early STOP codon - the protein will be incomplete
Chapter 12 Study Guide Answer Key.notebook
March 17, 2016
36. A change in the “frame” of the amino acid sequence by adding or deleting frameshift
nucleotides is called _______________________________ mutation.
a. Name and explain the 2 types of frameshift mutation.
deletion = a nucleotide has been lost
insertion = an additional nucleotide is added to the sequence
37. A change which causes entire codons to repeat is called
duplication
______________________________________________ mutation.
38. Give 2 factors that cause mutation to occur with DNA.
DNA polymerase could add the wrong nucleotide
Exposure to mutagens (radiation, chemicals, etc.)
39. (T/F) Mutations can cause proteins to function improperly or not at all.