- ) األول الدراسي الفصل الثمانية ) اختبار الجامعي المستوى هـ1438/ 1437للعام

Final Exam – 1st Semester (8th Level( For the Academic Year 1437/1438H-----------------------------------------------------------------------------------

Subject: Medical Genetics (MLAB 484(

Student Name: ------------------------------------------ Time: 2 hours

Student Number: ---------------------------------------- Marks: 40 Marks

Answer the following questions:

Question (1(: Choose the correct answer for the following (10x ½= 5 marks(

1. An allele is _____________

)a) another word for a gene)b) a homozygous genotype)c) a heterozygous genotype )d) one of several possible forms of a gene

2. The ____________ experiment demonstrated that bacteria are capable of transferring genetic information through a process known as transformation.

)a) Watson and Crick)b) Rosalind Franklin)c) Griffith )d) Mendel

Dr. Ghazala Muteeb Page 1 out of 11

المملكة العربية السعودية

وزارة التعليم

جامعة األمير سطام بنعبدالعزيز

كلية العلوم الطبية التطبيقيةبوادي الدواسر

Kingdom of Saudi Arabia

Ministry of Education

Prince Sattam Bin Abdulaziz University

College of Applied Medical Science in

Wadi Addawasir

3. ________________ is an ATPase that recognizes the DNA mismatch.

(a) MutL(b) MutH(c) MutQ(d) MutS

4. Phenotype refers to the ______________________ of an individual.

)a) genetic makeup )b) actual physical appearance)c) recessive alleles )d) All of the above

5. Sex chromosomes are represented as ____________________

)a) M and N)b) X and Y)c) D and L)d) T and t

6. The genotype of a monosomic cell can be represented as ____________

)a) 2n+1)b) 2n-1)c) 2n)d) n

7. When the centromere is at the middle position of chromosome so that the arms are equal and it appears ‘V-Shaped’, the chromosome is called _____________________

)a) metacentric )b) telocentric )c) acrocentric )d) sub-metacentric

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8. Which statement/s applies to interphase of cell cycle?

)a) Cells undergo majority of growth)b) Each chromosome replicates to produce sister chromatids which are attached at centromere)c) Consists of S, G1 and G2 phases)d) All of the above

9. The KRAS gene provides instructions for making a protein called ________

(a) EGF(b) R- Ras(c) K-Ras(d) Her-2

10. Which of the following syndromes have 47 chromosomes in each cell?

)a) Edward syndrome)b) Patau syndrome)c) Down Syndrome)d) All of the above

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Question 2: Put (T( if the statement is true and (F( if it is false. (6x ½ = 3 marks(

S.No. Statement Answer

1. Female mammals are actually mosaic for X chromosome expression.

2. Avery, MacLeod and McCarty demonstrated that DNA is the

substance that causes bacterial transformation.

3. Trastazumab is restricted to HER2-negative individuals.

4. Radioactive Carbon-14 was used to label the DNA of T2 phagein Hershey and Chase experiment.

5. Transcription starts at a region of DNA called a “splice site”.

6. In Escherichia coli, presence of the mismatch repair system

improves the fidelity of DNA replication by almost 1,000-fold.

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Question 3: Match column A with suitable answers in column B

(8x ½ = 4 marks(

Answer Column A Column B

1. Karyotype isA) was one of the first scientists to formally challenge

the theory of “spontaneous generation”.

2. Charles DarwinB) regions within a gene that do not code for protein

and do not appear in the final mRNA molecule.3. Anton vanLeeuwenhoek

C) proposed Germplasm Theory

4. Introns areD) coined the term “animalcules” to describe

tiny microorganisms.

5. Francesco Redi E) proposed the theory of pangenesis.

6. Phenylketonuria F) an ordered, visual representation of the chromosomesin a cell.

7. Knockout mouse G) is an inherited metabolic disorder.8. Chain termination method is H) a type of DNA sequencing.

I) is engineered so that it carries an inactivated gene.

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Question-4: Answer the following: (16 marks( A( Give the relevant genotype for the following syndromes. )3x 1 = 3 marks)

S. No. Syndrome Genotype

1. Klinefelter syndrome

2. Turner syndrome

3. Trisomy X

B( Give one example for each type of sex determination. )4x 1 = 4 marks)

S. No. Mode of Sex determination Example

1. XX-XO system

2. XX- XY system

3. ZZ- ZW system

4. Haplodiploidy System

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C( Fill in the table below to differentiate between prokaryotic and eukaryotic

ribosomes on the basis of their sedimentation rate. )6x ½ = 3 marks)

Type Size Large subunit Small subunit

prokaryotic

eukaryotic

D( Name one example of disease for each of the following cases: )6x 1 = 6 marks)

S. No. Case Name of Disease1

A specific deletion of a small portion of

chromosome 5

2Translocation of chromosome

3 Point mutation

4 Frame shift mutation

5 Autosomal dominant genetic disorder

6Autosomal recessive genetic disorder

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Question 5: Define the following: (6x1=6 marks(

1. Lethal genes-……………………………………………………………………………

……………………………………………………………………………………………...

2. Frameshift mutation-…………………………………………………………………..

……………………………………………………………………………………………...

……………………………………………………………………………………………..

3. Nondisjunction- ……………………………………………………………………….

……………………………………………………………………………………………..

4. Electropherogram-……………………………………………………………………

…………………………………………………………………………………………….

…………………………………………………………………………………………….

5. Mendel’s Law of Independent Assortment-…………………………………………

……………………………………………………………………………………………..

……………………………………………………………………………………………..

6. Incomplete Dominance-………………………………………………………………

…………………………………………………………………………………………….

…………………………………………………………………………………………

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Question 6: Answer any one of the following: (3 marks(

A( Suppose that a father is homozygous for the type “B” blood group , and mother is type “O.” blood group. What are all the possible blood types of their baby? (Do the punnett square(

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B( A carrier cystic fibrotic female marries a diseased cystic fibrotic male. Explain

wih the help of Punnett square the distribution of cystic fibrosis among their

offsprings.

Question 7: Deduce the amino acid sequence of the polypeptide chain formed from the provided mRNA sequence. Answer with the help of provided genetic code. (3 marks( Genetic code:

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mRNA sequence:

5’ AUG CCU CAG AAU CGC UCA UGU CUG AAG UUU AGG UAG 3’

Amino acid sequence:

…………………………………………………………………………………………….

The End_________________

Good Luck

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