ANSWER KEY FOR PROBLEM SET #1
1.Metaphase: 3; microtubules (spindle fibers) bind to the centromere; migration of the
centromere to the equatorial plate; shortest stage
Telophase: 5; cytokinesis (cytoplasmic division) occurs; nuclear envelopes being to
reform; chromosomes elongate
Interphase: 1; cell growth; replication of the DNA in each chromosome; longest stage
Prophase: 2; nuclear envelope disappears; chromatin condenses which causes the
chromosomes to appear; spindle fibers form
Anaphase: 4; sister chromatids separate and migrate to opposite poles in the cell;
shortest stage
NOTE: Other characteristics may be acceptable
2.egg, 130, sperm, 23, 10-15 hours, 48-72 hours, upper 1/3 of the oviduct, zygote,
fertilization, uterus, placenta
3.Amniocentesis: A procedure where a sample of amniotic fluid and cells is removed
from a woman who has been pregnant for 14-18 weeks. The purpose of the test is to
identify genetic, chromosomal, and biochemical abnormalities in a developing fetus.
Chorionic Villi Sampling (CVS): A procedure involving the collection of a sample of
cells from the outer of the two birth membranes (the chorion) and analyzed for
potential genetic and chromosomal defects in the embryo/fetus. The sample is
obtained at 6-10 weeks after fertilization
Ultrasound: The fetus can be “seen” in the mother’s womb. This procedure is used to
detect multiples, physical defects and the position of the developing fetus and
placenta. The procedure has no specific time limitations.
Endoamnioscopy: A technique permitting direct visualization of the developing fetus.
This procedure is used to detect abnormalities such as spina bifida and cleft lip. It has
no specific time limitations.
4.diploid- A condition where each cell has two of each kind of chromosome; 2n=46.
Body (somatic) cells are examples of cells that each contain a diploid number of
chromosomes.
Haploid- A condition where each cell has only one of each kind of chromosome;
n=23. An example of a haploid cell is an egg or sperm.
5.46 chromosomes x 2 chromatids per chromosome = 92 chromatids.
6.23 = 8 .
7.metacentric, submetacentric, acrocentric.
8.total length, centromere position, secondary constrictions and differential staining
bands; S phase portion of Interphase.
9.DNA is the genetic material. DNA is a triplet code, has punctuation, is anonoverlapping code, and is redundant or degenerate.
10.bases, phosphate, deoxyribose.
11.Adenine - purine, Cytosine - pyrimidine, Thymine - pyrimidine, Guanine - purine,
Uracil - pyrimidine
Thymine is found only in DNA; Uracil only in RNA
A & T are bound by double hydrogen bonds.
C & G are bound by triple hydrogen bonds.
12.Transcription, Translation.
13.messenger RNA - contains the coded information of a specific gene.
transfer RNA- carries specific amino acids to the sites of protein synthesis as a result
of the tRNA’s anticodons matching the codons of the mRNA.
ribosomal RNA- located in the ribosomes. . .the sites of the protein synthesis.
14.DNA template:
mRNA:
amino acid sequence:
CTATCTACAGGT
GAUAGAUGUCCA
Asp-Arg-Cys-Pro
15.A mutation is any transmissible change in the genetic material. Chromosomal
mutations are microscopically visible changes in the chromosome number or
structure; e.g. an extra chromosome #21. . .the cause of Down syndrome. A point
mutation usually involves a single nucleotide (base) pair, e.g. a substitution of one
base pair for another, a deletion or addition of a base pair.
ANSWER KEYS FOR TESTS #1
TEST #1 KEY
1.a.
FEBRUARY 5, 1999
Regulatory Protein - A class of proteins (gene products) involved in regulating
various activities in the body, e.g., insulin helps to control blood sugar levels,
testosterone . . . a hormone influences “masculinizing” traits, phenylalanine
hydrolase catalyzes the conversion of phenylalanine to tyrosine.
b.Carey H. Bostian - Former NCSU Chancellor and geneticist. Created GN 301 40 years
ago and contributed extensively to the development of “Genetics in Human
Affairs” in the early years.
c.AID - Artificial Insemination by Donor. Using sperm from someone other than
spouse/significant other to achieve fertilization and pregnancy. In so doing,
sterility, risk of transferring a known undesirable gene, Rh incompatibility, etc. can
be avoided.
d.S Phase - “Middle” part of Interphase where/ when DNA is replicated. S= Synthesis . . .
of DNA. Chromosomes become double, i.e., with sister chromatids as a result of
completing S.
e.t RNA - Transfer RNA. tRNA molecules carry specific amino needs to specific
locations on the surface of ribosomes, bond momentarily to specific mRNA
codons and transfer their amino acids to the growing chain of amino acids.
f.Thymine - One of the 4 DNA bases or nucleotides. A pyrimidine. Parts with Adenine
double hydrogen bonds to it. Not found in RNA.
2a.
2b.
2c.
2d.
2e.
A
B
D
E
A
2f.
2g.
2h.
2i.
B
A
A
B
3a.
3b.
3c.
3d.
D
B
C
A
4a.
4b.
4c.
4d.
4e.
4f.
4g.
4h.
4i.
4j.
4k.
F - haploid (or monoploid)
F - cytoplasm
T
F - oviducts (Fallopian Tubes) false part of statement
F- Thymine (or Deoxyribose)
T
F - the zygote (or embryo, or Blastocyst)
T
T
T
1 ½ for T; ½ for F, 1 for correcting False part of statement
5.Diagram to be made for answers.
6a.
Up to 4 points for each of two well communicated and documented responses.
6b.
Each must be reasonably well explained/elaborated. The two should be quite
different from each other.
7.a.
UGA
7b.
7c.
7d.
STOP
Punction, period, comma, etc . . . meaning no covering acid is add/inserted into
the gene product/protein for the mRNA codon. Instead, this signals the end of the
gene’s message . . .the translation of the code should STOP here.
AUG, UGG
50%, 50%
8a.
2003 (or 2004, or 2005)
8b.
80,000 (60,000 - 100,000 = OK)
8c.
3 Billion
8d.
NIH and DOE (or vice versa)
8e.
Either Good or Bad (zero points for “GOOD” or “BAD” Two points for quality of
explanation/documentation of why it is “Good” or “Bad”.)
9.5 points on Class Attendance Record.
10.Signature
TEST #1 KEY
1.a.
May 26, 1999
Amniocentesis - Method for obtaining fetal cells at 14-18 weeks prenatal to
analyze for any of > 100s of genetic and chromosomal problems, e.g., Down
Syndrome in females > age 35, family history of cystic fibrosis, etc.
b.Polar Body - Small cell produced in Meiosis (sex cell formation) containing a haploid
set of chromosomes. Contains little cytoplasm, this will not survive even if
fertilized. Its production permits the other haploid daughter product (the egg) to
have an enormous cytoplasm.
c.Genetic Engineering (Gene Therapy) - Procedure/technique for altering (changing)
DNA for therapeutic reasons, e.g., supplying the DNA to a person with Sickle
Cell Anemia to alleviate the health consequence.
d.AIH - Artificial Insemination by Husband. May be used to overcome a low sperm
count, a physical or emotional problem preventing fertilization via sexual
intercourse.
e.Human Genome Project - Mammoth effort to map and sequence all of the DNA in
human’s 24 chromosomes (22 autosomes, X, Y). i.e. to determine the location of
each of our ~ 80,000 genes and to identify the DNA stair step sequence of each.
f.Phenylketonuria (PKU) - Recessively inherited condition resulting from a block in the
normal conversion of phenylalanine to tyrosine. Toxic to CNS. Prenatal screening
to identify PKU individuals and to provide a diet low in phenylalanine spares
them from mental retardation.
2a.
2b.
2c.
2d.
2e.
F - two
2f.
T
T
F - implantation
F - galactose (to glucose)
3a.
3b.
3c.
3d.
B
C
D
A
4a.
4b.
Sperm, Zygote, Blastocyst, Fetus, Newborn
Uracil, Codon, Gene, Chromosome, Umbilical Cord
5a.
5b.
5c.
5d.
C
D
A
E
5e.
5f.
5g.
5h.
F - haploid (or monoploid)
2g.
F - Fertilization
2h.
F - anaphase
A
B
B
F
6.Up to 6 points for a well thought-out and elaborated response. 0 points for only
YES/NO answers. All 6 points for their discussion, explanation . . .and the genetic
sense it makes.
7.Up to 9 points total for two different well-discussed and explained reasons.
8a.
8b.
8c.
D
PKU (or Phenylketonuria)
F
9a.
9b.
9c.
9d.
UCA, Ser
UAG
UGG, AUG
35
10.
5 points on Class Attendance Record
11.Signature
TEST #1 KEY
1.a.
FEBRUARY 14, 2000
STOP Codon - Any of 3 different 3-letter mRNA or DNA codons which signal
the end of a gene’s message. No amino acid is added here. This always terminates
the translation process.
b.G  C - Three hydrogen bonds held/attract Guanine and cystosine to each other in DNA.
One of the 4 base pairs/stair steps found in our genetic code.
c.Replication - Occurs in the S phase of the cell cycle. DNA is doubled, resulting in sister
chromatids being formed, each with identical DNA molecules.
d.Sister Chromatids - The two longitudinal (left and right) identical halves of a replicated
chromosome. Contain identical DNA.
e.Fetoscopy (Endoamnioscopy) - Procedure whereby structures in the body/fetus can be
viewed. Utilizes a fiber optics light system to illuminate what one wants to
observe. Can detect, e.g. spina bifida.
2a.
2b.
2c.
200,000,000 (100,000,000 - 300,000,000)
50 (25-100)
1) Acidic vagina
2) sperm “seen” as foreigners . . . attacked by female antibodies
3) long distance to swim
4) many male sperm are defective.
5) sperm may try to fertilize any round object, not necessarily egg
6) swim up the wrong Fallopian tube
7) other reasons
3a.
3b.
3c.
F - cytoplasm
T
F - protein
4a.
4b.
4c.
4d.
4e.
4f.
F - oviducts/Fallopian tubes
T
F - less
F - implantation
F - haploid (or monoploid)
T
5a.
5b.
5c.
5d.
A
A
C
C
3d.
3e.
3f.
5e.
5f.
5g.
F - thymine (or uracil)
T
F - Proteins are
D
C
B
6a.
1)map all of our genes to specific chromosome, arm, band, etc.
2)determine DNA stair step sequence for each gene . . . all of the DNA.
6b.
2005 (possibly earlier, say, 2002-2003)
7a-7b. YES/NO is 1 point. 3 points for quality of reasoning . . . and
explanation/elaboration. (Must include genetic perspective.)
8a.
8b.
8c.
Albinism
F
D
9a.
9b.
9c.
9d.
C
B
E
D
10a.
10b.
rRNA, Ribosome, Cell, Tissue, Organ
DNA Base Pair, Codon, Gene, X chromosome, Chromosome #1
11a.
11b.
11c.
CUA, Leu
AGU
28
12.Signature
TEST #1 KEY
1.a.
SEPTEMBER 25, 2000
Sperm Cell - Haploid; n=23; gamete; capable of fertilizing egg; product of
meiosis; little cytoplasm; motile/mobile; each one is unique genetically; 85,000
times smaller than egg.
b.Autosome - A non sex chromosome; #1 - #22; Not X or Y
c.Galactosemia - Due to a block in the conversion of galactose to glucose, galactose
accumulates and is toxic to CNS development, the result: mental retardation.
Inherited as an autosomal recessive (gg) gene. Dietary limitations of galactose
eliminate the consequences.
d.U:A - Uracil double hydrogen bonds to adenine when given the opportunity, e.g., in
mRNA/tRNA attraction in translation. Uracil is a pyrimidine, Adenine is a purine.
e.Carey H. Bostian - Former NC State Chancellor created GN 301; Dr. McKenzie’s
mentor; Bostian Hall named for him, recently died.
f.Cousin Marriages - Increases the risk of children having genetic defects since all of us
have (are carriers for) several “bad” genes, and some cousins share many genes
(being 1/8 identical); the chance that a child would receive a double dose is
increased.
2a.
2b.
2c.
B
D
A
2d.
2e.
C
A
3a.
3b.
3c.
250,000,000 (+/- 100,000,000)
50 (+/- 25)
1)many sperm are defective
2)hostile, acid uterine/vaginal environment
3)attacked by antibodies
4)swim up the “wrong” oviduct/Fallopian tube
5)fertilize any round object
6)it’s a long distance to swim
7)others?
4a.
4b.
4c.
C
D
B
5a.
No, no need for carrier testing, i.e. your “affected” child proved that both you and
your mate are carriers . . . unless you have reason to suspect that the husband is
not the father.
Either YES or NO. Up to 3 points for why/why not. Be fairly generous here, but
must make sense in a GN 301 context.
5b.
6a.
6b.
6c.
4d.
4e.
4f.
B
E
A
E
PKU (Phenylketonuria)
C
7a.
7b.
7c.
1)Map . . . to determine the specific chromosomal locations of each of our ~
80,000 genes.
2)Sequence . . . to identify all of the DNA base pairs, their order, arrangement . .
for all 3+ billion stair steps.
~ 2003 - 2005, although a rough draft is already finished (early 2000)
1)human health/medical applications
2)better understanding of our nature
3)more accurate studies of evolutionary relationships
7d.
1)genetic discrimination by insurance companies, employers, or governments.
2)Money/cost
3)Moral, religious, etc. objections, i.e. “playing God”
8a.
8b.
Sperm, Zygote, Embryo, Fetus, Newborn
Ribose, mRNA Molecule, Chromosome #22, Chromosome # 2, Nucleus
9a.
9b.
9c.
AUG, Met
AGU
UGG UAU (or UGG UAC)
9d.
31 %
9e.
No, 21 code words would be needed; 20 for 20 amino acids plus 1 for STOP. A
doublet code would yield 4x4 = 16 code word . . . NOT enough to code for 21 things.
10a.
10b.
10c.
F - and
10d.
F - protein
F - anaphase
T
10e.
10f.
T
F - cytosine, three
11.Up to 5 points for Class Attendance Record.
12.Signature
TEST #1 KEY
1.a.
FEBRUARY 9, 2001
Human Genome Project - Mammoth effort to map and sequence all human
genes/DNA, i.e. to identify the specific chromosomal location of each of the
75,000 genes +/- genes and to determine the stair step sequence of each. A rough
draft is already completed.
b.Carey H. Bostian - Founder/creator of GN 301 . . . 40+ years ago; former NC State
Chancellor, Bells in Bell Tower and Bostian Hall are both named for him, noted
geneticist, Dr. McKenzie’s mentor.
c.Amniocentesis - Procedure used during 14 - 18 weeks of pregnancy to obtain fetal cells
for a DNA genetic/chromosomal analysis. Hypodermic syringe/needle used to
collect cells from amniotic cavity. Can identify, e.g. Down Syndrome and Cystic
Fibrosis.
d.Diploid - 2n = 46. Chromosomal content of zygote and all cells that descend from it
mitotically . . . thus we are diploid individuals; and a diploid species.
e.Anaphase - Stage of mitosis where chromosomes are being pulled by spindle fibers
from the center of the cell toward the poles/sides of the cell.
f.Hypotonic Treatment - Used to swell cells and consequently spread out chromosomes
so they can be seen easily/individually when examined under a microscope.
2a.
2b.
2c.
2d.
2e.
F - 2n = 46
F - uterus (or endometrium)
F - preventing ovulation
F - cytoplasm
F - telophase
2f.
2g.
2h.
T
T
T
3a.
3b.
Sperm, Egg, Embryo, Fetus
Codon, Gene, Chromosome #11, Chromosome # 7
4a.
4b.
4c.
4d.
D
C
B
A
4e.
4f.
4g.
B
D
A
5a.
5b.
5c.
5d.
A
B
C
A
6.a.
YES or NO. Testing (DNA, gene, chromosomal) at some stage prior to
implantation: e.g. egg or sperm. Zygote, at 8 cell stage, etc . . . OK, if they
indicate testing of parents preconceptionally. NOT OK if they are testing by
amniocentesis or CVS. Response must make sense in a GN 301 context.
b.Modifying genes/DNA of zygote (fertilized egg) . . . or up to 8 cell stage. YES or NO.
Response must make sense in a GN 301 context.
7a-7b. Up to 4 points for each of two well documented “aspects” which clearly show
they saw/experienced the “Miracle of Life” video.
8a.
8b.
8c.
D
B
Albinism
9a.
9b.
9c.
9d.
9e.
UCA, Ser
CAU
AUG UGG
39
No, a triplet code allows for 43 = 64 codons. A doubt code allows for 42 = 16
codons. 21 codons are needed: 20 for the amino acids and 1 for the STOP codon.
Therefore, a doublet code would not have been sufficient.
10.Up to 5 points for Class Attendance Record.
11.Signature
TEST #1 KEY
SEPTEMBER 24, 2001
1.
a. Mapping and Sequencing - Goals of the Human Genome Project: to identify the
location of each gene specific to chromosome and chromosome region (mapping), and to
identify the DNA base pair/stair step ordering of all 3 billion steps (sequencing).
b. Placenta - Organ made by both fetus and mom through which nutrients, gases,
wastes, etc. traffic to and from embryo/fetus from Mom.
c. Chromosome #1 - Our biggest (longest) chromosome/autosome. Lots of important
genes; metacentric.
d. Blastocyst - The ball of cells post zygote -> to embryo stage. By 7-10 days after
fertilization,the blastocyst will be approximately 27-10 (or approximately 100-1000) cells
that implants in the uterine wall. After that, more specific tissues to organs begin to form,
i.e. the embryo begins to develop.
e. Amniocentesis - Means of testing the DNA, genes, chromosomes, biochemicals by
14-18 week fetus. Needle is inserted transabdominally in mom and 30+/- 10 cc of
amniotic fluid and cells are removed. Ultrasound is used to guide the needle.
f. Tyrosinemia - Very rare ailment due to a block in the degradation of tyrosine.
Autosomal recessive, e.g., tt genotype, causes it. Joshua (Raleigh 4 year old) is the only
living NC individual who has it!
2.
a.
b.
c.
d.
e.
f.
g.
h.
F, interfering with sperm being deposited in vagina at intercourse.
F, adenine
F, phenylalanine to tyrosine
F, oviducts (Fallopian tubes)
F, metaphase
T
F, S (S Phase, replication)
T
a.
b.
c.
d.
A
E
C
D
a.
b.
c.
d.
e.
f.
g.
h.
E
D
A
B
B
C (only half credit for A or B)
F (only half credit for B or C)
D
3.
4.
5.
a.Sperm, Zygote, Embryo, Fetus
b.Codon, Gene, Y Chromosome, Chromosome #11
6a-6b. Up to 4.5 points for each of two different aspects of the "Miracle of Life" video
which clearly
communicate having gained from watching it and remembering it.
7a-7b. Up to 4 points for a well thought out, well communicated response that makes GN
301 sense given
the scenario. Either "Yes" or "No" is fine. It's the quality of the thinking behind it that can
earn up to 4
points.
8.
a. albinism
b. D
c. F
9.
a.
b.
c.
d.
AUG, Met
AGU
UGG UAU (or UGG UAC)
27
10. Up to 4 points for Class Attendance Record.
11. Signature, Student ID Number
TEST #1 KEY
FEBRUARY 8, 2002
1.
a. Carey H. Bostian - Former NC State Chancellor and Genetics Professor. Originated
GN301 and taught it initially more than 4 decades ago. Bostian Hall is named after him.
b. Genetic Discrimination - Concerns regarding the possible use of genetic test results
to make decisions by employers, insurance companies, governments, and others on their
employees or applicants, health/life insurance policy holders, tax benefits or deductions,
etc. Federal and State laws are being enacted to prevent such.
c. Fetoscopy or Endoamnioscopy - Procedure used to look at fetus and potentially
detect developmental problems. Seldom used, except for research and photography
educational purposes.
d. PKU - Phenylketonuria. Due to a block in conversion of phenylalanine to tyrosine.
Inherited as a recessive, i.e. it takes a pp (double dose of p) to not make the necessary P
enzyme which catalyzes the conversion. Newborns are screened for it, and can prevent
problems by dietary modifications.
e. DNA, the Universal Language - All of life. . .from the simplest forms to humans
have DNA as their genetic code. We all use the same chemical hereditary language, rules,
and all.
f. Autosome - Any of the non sex chromosomes, i.e. the numbered ones, 1-22.
2.
a.
b.
c.
d.
e.
f.
g.
h.
F, keeping sperm from being deposited in vagina during sexual intercourse.
F, tyrosine to melanin
T
T
T
F, adenine,two
T
T
a.
b.
c.
d.
B
D
A
C
a.
b.
c.
d.
e.
f.
g.
h.
D
F (half credit for B or C)
C
E
D
C (half credit for A or B)
D
A
3.
4.
5.
a.Gene, Chromosome, Sperm, Egg
b.Amino Acid, Enzyme, Ribosome, Cytoplasm
6a-6b. Up to 4.5 points for each of two different, reasonably well elaborated aspects that
draw from the "Miracle of Life" video.
7a. Response needs to at least imply that "Preimplantation". . .loosely defined. . .as any
time before the
blastocyst/ball of cells reaches the uterus, e.g. could be testing of egg, sperm, zygote, one
of the cells at
approximately the 8 cell stage, or even testing of potential parents before sexual
intercourse leading to
conception.
7b. Responses need to address testing for part a, therapy/genetic alteration for part b. Yes
or No doesn't matter. What matters is that it makes GN301 sense and is reasonably well
elaborated.
8.
a.6
b.4
c.PKU
9.
a.CAU, His
b.CAT, 3+2+2=7
c.AUG UGG
d.18
10. 5 points for completing the survey.
11. Signature
TEST #1 KEY
September 20, 2002
1.
a. AIH - Artificial Insemination by Husband. Used, e.g., when husband has low
sperm count. By collecting semen from several ejaculations and inserting the
combined collections into the vagina via artifical insemination. This way the
couple may be able to overcome infertility.
b. Sister Chromatids - Sister chromatids are the two longitudinal identical halves of
a replicated chromosome. They contain identical DNAs.
c. Spindle Fibers - During mitosis spindle fibers attach to each side of each
chromosome's centromere and pull the chromosomes to the proper places. They
enable chromosomes to move.
d. Diploid - 2n = 46. Diploid cells have chromosomes represented in pairs, e.g., two
#1s, two #2s, etc. The zygote is diploid as are all the somatic cells that descend
via mitosis from it.
e. Human Genome Project - The monumental NIH and DOE (federal) and private
research effort to map and sequence all of the genetic information (DNA) in
humans. . .all 3+ billion stairsteps, 30,000+ genes. As a consequence, the location
of and spelling of all our DNA is now known and was completed in 2000.
f. Carey H. Bostian - Former NC State Chancellor. Originated GN 301 over 40
years ago. Bostian Hall and Bell Tower bells named for him. Dr. McKenzie's
mentor.
2.
a. T
b. F, uterus or endometrium
c. T
d.
e.
f.
g.
h.
F, preventing sperm from reaching an egg
F, haploid or monoploid
F, acrocentric
F, metaphase
F, Deoxyribose to Ribose
a.
b.
c.
d.
A
C
B
E
a.
b.
c.
d.
e.
f.
g.
h.
F (half credit for B or C)
A
C (half credit for A or B)
A
D
A
E
B
3.
4.
5.
a. Sperm, Egg, Embryo, Fetus
b. Codon, Gene, X Chromosome, Chromosome #1
6.
a. 1. They have the same salt concentration.
2. Cilia that line the female reproductive tract are identical to those of single-cell
organisms in the sea.
b. 1. Males produce low/slow amounts of regularly/uniformly. It's at a constant
level.
2. Females produce bursts of hormones cyclically/monthly.
c. 1. Adverse acidic environment of female reproductive tract.
2. Attacked by white blood cells of female's immune system.
3. Downward current which sperm must swim against.
4. Many sperm are defective: two tails, etc.
5. Some sperm fertilize other round objects/cells and don't make it to the egg.
6. Some sperm swim up the wrong oviduct/Fallopian tube.
7.
a. D
b. E
c. PKU or Phenylketonuria
8.
a.
b.
c.
d.
e.
AGU, Ser
GUA
AUG UGG
34%
No. A doublet code (assuming the code uses the 4 bases A,G,C, and T) would
enable/generate 42 = 16 code words. 21 are needed; 20 for the 20 amino acids
(one each) and 1 for punctuation (STOP). Such a system would not be sufficient
9. Up to 7 points for a well thought out, well supported statement reflecting a GN 301
perspective. Either YES or NO is fine. Grading/score is based on the quality of thinking
(and communication of it) which supports the "answer".
10.
a.
b.
c.
d.
e.
T
F, Blue (or Gray)
T
Corrections
Up to 2 points for a clear communication that indicates you actually saw and
learned from this exhibit.
11.Signature