chapter 17 practice questions- complete by Friday 11/23/2011

Chapter 17 From Gene To Protein: Practice questions

Multiple Choice

Identify the letter of the choice that best completes the statement or answers the question.

____    1.   Base-pair substitutions involving the third base of a codon are unlikely to result in an error in the polypeptide. This is because

a.	substitutions are corrected before transcription begins.
b.	substitutions are restricted to introns.
c.	the base-pairing rules are less strict for the third base of codons and anticodons.
d.	a signal-recognition particle corrects coding errors.
e.	transcribed errors attract snRNPs, which then stimulate splicing and correction.

____    2.   In eukaryotic cells, transcription cannot begin until

a.	the two DNA strands have completely separated and exposed the promoter.
b.	several transcription factors have bound to the promoter.
c.	the 5' caps are removed from the mRNA.
d.	the DNA introns are removed from the template.
e.	DNA nucleases have isolated the transcription unit.

____    3.   Which of the following is not true of a codon?

a.	It consists of three nucleotides.
b.	It may code for the same amino acid as another codon does.
c.	It never codes for more than one amino acid.
d.	It extends from one end of a tRNA molecule.
e.	It is the basic unit of the genetic code.

____    4.   The metabolic pathway of arginine synthesis is as follows:

Precursor		Ornithine		Citrulline		Arginine
	A		B		C

Beadle and Tatum discovered several classes of Neurospora mutants that were able to grow on minimal medium with arginine added. Class I mutants were also able to grow on medium supplemented with either ornithine or citrulline, whereas class II mutants could grow on citrulline medium but not on ornithine medium. From the behavior of their mutants, Beadle and Tatum were able to conclude that

a.	one gene codes for the entire metabolic pathway.
b.	the genetic code of DNA is a triplet code.
c.	class I mutants have their mutations later in the nucleotide chain than do class II mutants.
d.	class I mutants have a nonfunctional enzyme at step A, and class II mutants have one at step B.
e.	class III mutants have nonfunctional enzymes for all three steps.

____    5.   The anticodon of a particular tRNA molecule is

a.	complementary to the corresponding mRNA codon.
b.	complementary to the corresponding triplet in rRNA.
c.	the part of tRNA that bonds to a specific amino acid.
d.	changeable, depending on the amino acid that attaches to the tRNA.
e.	catalytic, making the tRNA a ribozyme.

____    6.   Which of the following is not true of RNA processing?

a.	Exons are cut out before mRNA leaves the nucleus.
b.	Nucleotides may be added at both ends of the RNA.
c.	Ribozymes may function in RNA splicing.
d.	RNA splicing can be catalyzed by spliceosomes.
e.	A primary transcript is often much longer than the final RNA molecule that leaves the nucleus.

____    7.   Which of the following is true of translation in both prokaryotes and eukaryotes?

a.	Translation is coupled to transcription.
b.	The product of transcription is immediately ready for translation.
c.	The codon UUU codes for phenylalanine.
d.	Ribosomes are affected by streptomycin.
e.	The signal-recognition particle (SRP. binds to the first 20 amino acids of certain polypeptides.

Use the table of condons below to answer the following questions.

Use Diagram in book- stop and start codon diagram- The one with the chart!

____    8.   Using the genetic code in the table, identify a 5'  3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys.

a.	UUU-GGG-AAA
b.	GAA-CCC-CTT
c.	AAA-ACC-TTT
d.	CTT-CGG-GAA
e.	AAA-CCC-UUU

____    9.   Which of the following mutations would be most likely to have a harmful effect on an organism?

a.	a base-pair substitution
b.	a deletion of three nucleotides near the middle of a gene
c.	a single nucleotide deletion in the middle of an intron
d.	a single nucleotide deletion near the end of the coding sequence
e.	a single nucleotide insertion downstream of, and close to, the start of the coding sequence

____  10.   Which component is not directly involved in translation?

a.	mRNA
b.	DNA
c.	tRNA
d.	ribosomes
e.	GTP

Please expect a chapter 17 assessment :) enjoy your procrastinating Sunday!

Please do not forget to do the questions at the end of the lab procedure.

Chapter 16 study guide- Must be completed as you walk into class next time I see you! Please expect an assessment for chapter 16 :)

AP Biology

STUDY GUIDE: CH. 16

“THE MOLECULAR BASIS OF INHERITANCE

Key terms:

            Transformation                                                                                 DNA ligase

Bacteriophages                                                                                 primer

Phage                                                                                                 primase

Double helix                                                                                     helicase

Semiconservative replication                                                         single-strand binding protein

Origins of replication                                                                      mismatch pair

Replication fork                                                                               nuclease

DNA polymerase                                                                             nucleotide excision repair

Leading strand                                                                                 telomere

Lagging strand                                                                                 telomerase

Objectives:

1. Summarize the experiments performed by the following scientists that provided evidence that DNA is the genetic material: Griffith; Avery; McCarty; MacLeod; Hershey and Chase; Chargaff.
2. Explain HOW Watson and Crick deduced the structure of DNA and describe the evidence they used.  Explain the significance of the research of Rosalind Franklin.
3. Describe the structure of DNA. Explain the “base-pairing rule” and describe its significance.
4. Describe the semiconservative model of replication and the significance of the experiments of Meselson and Stahl.
5. Describe the process of DNA replication. Note the structure of the many origins of replication and replication forks and explain the role of DNA polymerase.
6. Define”antiparallel” and explain why continuous synthesis of both DNA strands is possible.
7. Distinguish between the leading and lagging strand.
8. Explain how the lagging strand is synthesized even though DNA polymerase can add nucleotides only to the 3’ end.
9. Explain the role of DNA ligase, primase, helicase, and the single-strand binding protein.
10. Explain the roles of DNA polymerase mismatch repair enzymes, and nuclease in DNA proofreading and repair.
11. Describe the structure and function of telomerases.  Explain the significance of telomerase to healthy and cancerous cells.

chapter 14. Mendel and the gene idea

chapter 14. Mendel and the gene idea

Q. what is the phenotypic percentage of f1 generation from two purple true-breeding parents ?

Q. why did Mendel choose pea plants for experiment?

Q. what is benefitial to use punnett square?

five facts

1. traits are transmitted from parents to offspring

2.

Mendel’s experiments succeeded because he counted so many offspring and was able to discern this statistical feature of inheritance and had a keen sense of the rules of chance.

3.

Mendel’s laws of independent assortment and segregation explain heritable variation in terms of alternative forms of genes that are passed along according to simple rule of probability.

4.

These laws apply not just to garden peas, but to all other diploid organisms that reproduce by sexual reproduction.

5.

Mendel’s law of segregation accounts for the 3:1 ratio that he observed in the F₂ generation.

key terms

1. character : a heritable feature that varies among individuals, such as flower color

2. true-breeding : such plants that had poduced only the same variety as the parent plant

3. hybridization : two true-breeding varieties

4. P generation : the true-breeding parents

5. F1 generation : first filial generation

6. F2 generation : second filial generation

7. alleles : alternative version of a gene

8. dominant allele : determines the organism's appearance

9. recessive allele : has no noticeable effect on the organism's appearance

10. law of segregation : the two alleles for a heritable character segregate (separate) during gamete formation and end up in different gametes

diagram

this diagram shows me the process of what Mendel had done to Pea plants. First he cut out the stamens from the purple flower in order to prevent self-polinating. Second he purposely moved sperm- bearing pollen from stamens forom white to egg-bearing carpel of purple. and he planted the result seeds. The result was all purple flowers appeared and he kept on doing the same process with the F1 generagion again.

video

http://www.youtube.com/watch?v=eOvMNOMRRm8&feature=related

summary

basically Mendel used the scientific approach to prove the two laws of inheritance which was the law of segregation and the law of independent assortment. He used detailed and a lot of information brought him to the father of genetic. the law of segregation is the two alleles for a character are packaged into separate gametes and the law of independent assortment is each pair of alleles segregates into gametes independently.

link to all pre-labs!

http://www.phschool.com/science/biology_place/labbench/

have fun :)