Fatimah Baghdadi
Exam correction for Edu 301
I. Answer each of the following statement by placing the letter T next to
those that are true and the letter F next to those that are false and
correct the false ones: ( 2min all)
..…T………1. When a plant produces an identical offspring this is called true breeding.
……F ..…...2. The inherited physiological characteristics of an individual are referred to as
genotype.
phenotype
……F..……3. Plants of same phenotype are of same genotype.
it is not necessary to be always of same
……F..……4. The off spring of crosses between parents with different traits are called genes.
traits
……T..……5. Alleles are the different forms of the gene
(2.1: Identify genes, alleles, genotype, and phenotypes, true breeding and hybridization. )
……T..……6. A Mutation occurs when a DNA gene is damaged or changed in such a way as to
alter the genetic message carried by that gene.
……F……7. .Down syndrome karyotype is of 46 chromosomes.
47
( objective 5.2 distinguish between genetic diseases )
……F……8.Aneuploidy is also called structural abnormalities in chromosome.
numerical abnormality
……T……9.In humans, Down syndrome is when an individual has three copies of chromosome
21, rather than two.
( objective 5.4: .4: Differentiate the numerical from the structural chromosomal abnormalities. )
scoring: 1 point for true
0.5 for false and 0.5 for correction
II.
1. Label each organ. The
figures below show a female
and male reproductive
system, label the numbered
part( 8 min)
scoring :0.25 for each name
( Objective 1.1 : Identify the different organs of the male and female reproductive system )
1. uterus
5.clitoris
2.urinary bladder
6.labium minora
3.symphysis pubic
7.labium majora
4.urethra
8.viginal orifice
1.bladder
2.vas deferens
3. urethra
4. penis
5.scrotum
6.epididymis
7.testis
8.prostate gland
9.seminal vesicle
2. Choose from the list below one answer for each picture choose the
appropriate phase of meiosis, each phrase can be used once (2min)
scoring : 0.5 each correct name even with misspelled words but can be
understood
(1.3: Differentiate between the phases of meiosis)
A. prophase I
B.metaphase I
C. anaphase I
D. telophase I
E. prophase II
F.metaphase II
G. anaphase II
H. telophase II
A
I. interphase
H
G
I
F
III.Choose the best answer:
(3min)
scoring: 1 point for each
1. What is a phenotype? :
a. Genetic makeup of an organisms
b. the off spring of crosses between parents with different traits
c. physical characteristics of an
organism
d. chemical characteristics that vary
from one individual to another
(2.1: Identify genes, alleles, genotype, and phenotypes, true breeding and hybridization. )
2. what is the disorder of a child that is mentally retarded having wide, rounded face, and enlarged
tongue that makes him speak with difficulty?
a. down syndrome
b. trisomy13
c.monosomy
(5.2 distinguish between genetic diseases and their characteristics)
3. Klinefelter syndrome is a genetic disorder that affects
a. males only
b. females only
c. both gender
5.2 distinguish between genetic diseases and their characteristics)
4.what are the types of trisomy :
a. trisomy 21,14,17
b.trisomy 21,18,13
c.trisomy 21,15,13
(5.2 distinguish between genetic diseases and their characteristics
5. Growth retardation problems such as (short stature, webbing of the neck, low posterior
hairline, broad chest, cubitus valgus are symptoms of :
a. turner syndrome
b. trisomy 21
c.klinefelter syndrome
(5.2 distinguish between genetic diseases.)
6.All the following are types of structural abnormalities except:
a.monosomy
b. duplication
c. depletions
d. Isochromosome
(objective 5.4:Differentiate the numerical from the structural chromosomal abnormalities. )
7.which of the following takes place during the prophase?
a. Nucleoli appear in the two new nuclei
b. the mitotic spindle is fully formed
c same chromatics joined at the centromere
(1.3: Differentiate between the phases of meiosis)
IV. Restricted items: ( 35 min)
Answer the following:
1. Differentiate
between diploid and haploid cells
(1.2: Differentiate between diploid and haploid cells.)
Diploid refer to a cell that contains both sets of homologous chromosome
haploid refer to a cell that contains onlu a single set of chromosomes and therefore only a single
set of genes.
rate scale: 0.5 pt for diploid
0.5 pt for haploid
2.Compare and contrast spermatogenesis and oogenesis indicate (3 differences and 2 common).
( 1.4: compare and contrast between spermatogenesis and oogenesis.)
Spermatogenesis occurs in the testes ,no polar body is formed, a spermatogonium forms four
spermatozoa, whereas, oogenesis occur in the ovaries, polar bodies are formed, oogonium forms only
one ovum. but both are included in the meiosis and produce 4 haploid daughter cells
rate scale: 1 pt for differences
1 pt for comparison
3. Fertilization definition?
( 1.5: define fertilization.)
Human fertilization is the union or joining of the egg and the sperm, resulting in a fertilized
egg, otherwise known as a zygote. But the process of human fertilization is very complicated and
comprised of many steps and components necessary to achieve the ultimate result of human life.
rate scale: 1 pt for brief and meaningful definitiom
4. What are the types of alleles?
( 2.2 determine allele types )
A dominant allele produces a dominant phenotype in individuals who have one copy of the
allele, which can come from just one parent.
For a recessive allele to produce a recessive phenotype, the individual must have two copies, one
from each parent.
An individual with one dominant and one recessive allele for a gene will have the dominant
phenotype
rate scale: 1 pt for dominant allele
1 pt for recessive allele
5.Explain the random combination of
gametes upon fertilization.
(2.3 explain the random combination of gametes upon fertilization)
The sperm mother cell produces upon fertilization four different gametes of different genes. we
will not know which will fertilize the ovum to form the zygote
Rating scale: 1 pt for menting that there will be 4 gametes
1 pt for mentioning '' we will not know which will fertilize the ovum to
form the zygote''
6. Explain how mutation affects coding sequence.
( objective 3.2 explain how mutation affects coding sequence. )
Mutation affect the nitrogenous bases of DNA, then when the triplets are affected the coding is
also changed and different amino acids join to produce new protein.
Rating scale: 1pt for mentioning " nitrogenous bases of DNA''
1 pt for how protein is produced
7. Define polymorphism
( 3.3: define polymorphism )
Means that individuals are diverse (different),they differ in external phenotypes as hair color or internal
phenotype as blood groups.
rate scale: 1 pt for brief and meaningful definition
8.
If when sampling a population, you know that the frequency of the recessive phenotype is
64% for a certain gene.
1) why does this frequency correspond to q2?
2)calculate the frequency of :
a)
b)
c)
d)
Allele 'a'
Allele 'A'
genotype AA
genotype Aa
Answers:
1.individuals with recessive character are always homozygote because recessively is a
criterion of purity then their corresponding genotype is 'aa' matched with q2
rating scale : 1 pt
2. a. frequency of 'a' =q=√ qᶺ 2= 0.08=8%
b. q+p =1 then q= 1-0.08=0.02=2%
c. AA ,then p2 (0.02)2=0.04=4%
d. Aa, then 1qp= 2x0.02x0.08 =0,32=32%
(2.4 : use allele principle to solve exercise )
rate scale: 1 pt for each part if the steps and the right answer were
mentioned
9. .If curly-haird individuals are genotypically CC, strait-haired are cc, and wavy haired
individuals are heterozygotes (Cc), what percentage of various phenotypes would be anticipated
from a cross between a CC woman and a cc man?
Curly: 0%
Wavy: 100%
Straight: 0%
(2.5: find genotype and phenotype)
rate scale: 1 pt for having all right answers
1pt for the process
10. In dewey's family , farsightedness is inherited by possession of a dominant allele (A). If a
man who is homozygous for normal vision (aa) marries a woman who is heterozygous for
farsightedness (Aa), what proportion of their children would be expected to be Farsighted?
_____%
if the man is aa he can donate aor a to his child. the woman can donate A or a .So the possibilities are :
Aa,Aa, aa, aa so 50% of the time they'll be Aa ,50% aa. farsightedness is Aa, so 50%
(2.5: find genotype and phenotype)
(5.3: Calculate the risk of a couple having an affected child.)
rate scale: 1pt for having the genotype correct
rate scale: 2 pt if the percentage were right
11. In human species, color vision is determined by several genes. One of these genes, which is
localized on the sex chromosome X, has two alleles :
▪ a dominant allele N determining normal color vision.
▪ a recessive allele d determining abnormal color vision or daltonism.
A man has 2 different sex chromosomes X and Y while a woman has 2 identical sex
chromosomes X and X. They have a baby boy
a- based on the above information: Construct the pedigree (genealogical tree) of this family.
( 5.1: Construct a pedigree )
rate scale: 2 pt for constructing a pedigree
b- Write the genotype of the :
- father
- mother
- daltonian boy .
(2.5: find genotype and phenotype)
rate scale: 1 pt for correct genotypes
Good Luck 