Republic of the Philippines

Tagum City National High School Visayan Village, Tagum City

THIRD PERIODICAL EXAM IN BIOTECHNOLOGY SY 2014 – 2015

Name:_____________________________

Section:_____________

Directions (1–50): For each statement or

question, encircle the letterof the word or

expression that, of those given, best completes the statement or answers the question.

1. Who discovered that DNA has equal

amounts of bases? a. Phoebus Levine b. Erwin Chargaff

c. Rosalind Franklin d. Maurice Wilkins

2. Who identified the four bases of NA? a. Erwin Chargaff

b. Phoebus Levine c. Maurice Wilkins

d. James Watson 3. DNA structure is held together by?

a. Nitrogenous bases b. hydrogen bonds

c. sugar molecule d. phosphate molecule

4. In DNA, adenine always pairs with? a. thymine

b. cytosine c. uracil d. guanine

5. Nucleotides are arranged in functional

segments called? a. genes b. helix

c. amino acid d. hydrogen bond

6. What is the enzyme responsible for splitting the two strands of DNA?

a. ligase b. helicase

c. polymerase d. primase

7. The structure that is formed within the nucleus during DNA replication.

a. Single strand b. Okazaki fragments c. Replication fork

d. polymerase template

8. It is the formation of a specific RNA sequence from a specific DNA sequence. a. Replication

b.Translation c. protein sequence

d. transcription 9. Carry the coding sequences for protein

synthesis a. tRNA

b. mRNA c. rRNA d. RNA

10. It is either a loss or gain of part of

chromosomes. a. point mutation b. gene-level mutation

c. chromosomal mutation d. somatic mutation

11. It is the failure of chromosome to separate during meiosis causing gamete to

have too many or too few chromosomes. a. nondisjunction

b. translocation c. duplication d. inversion

12. Based on Erwin Chargaff’s study, if there are 12 cytosine on a single strand of

DNA, how many Thymine would be on the other strand?

a. 8 b. 12 c. 88

d. none of the above

13. Directionality has consequences in DNA synthesis because DNA polymerase can only synthesize DNA in what direction?

a. 5’ b. 3’

c. 3’5’ d. 5’3’

14. Which of the following statement about RNA is not true?

a. it contains the sugar ribose b. it contains the base uracil instead of thymine

c. it contains anti-parallel strand d. it is a nucleotide

15. How does nitrogenous bases distributed in DNA structure?

a. the amount of A-T pair is twice the amount of C-G pair

b. the amount of A-T pairs and C-G pairs are equal. c. the amount of C-G pair is twice the

amount of A-T pair. d. none of the above

16. Why does A always pairs with T and C always pair with G?

a. Because of the number of hydrogen bonds the bases form

b. Because of the helical structure lies with the bases c. Because of the sugar used by the DNA

d. Because it is discovered by Rosalind Wilkins

17. Identify the complimentary base of this DNA nucleotides a t g c g t a c a t

a. t a c g c a t c t a b. t a c g c t t g t a

c. t a c g c a t g t a d. t a c g g a t g t a

18. Why does unwounding of two strands

during DNA replication occurs in chains which are rich in A-T pairs? a. because there are no hydrogen bonds

b. because there are only 3 hydrogen bonds

c. because there are only two hydrogen bonds d. because it is in a helical structure

19. Protein synthesis a continuous process

a. yes, ribosomes never stop synthesizing protein b. no, proteins are synthesized only when

needed by the cell c. yes, there is no enzyme that stops the

synthesis d. no, protein synthesis occurs only once a day

20. How does termination of protein

synthesis occur? a. when there is no enough rRNA b. when the cell has insufficient amount of

protein c. when ribosome reaches methionine

d. when ribosome reaches one of three stop codons

21. Which comes first in the process of protein synthesis

a. translation, translocation, transcription b. replication, transcription, translation c. replication, transcription, translocation

d. transcription, translation, translocation

22. Why does each new double helix is called semi-conservative replication after the

DNA replication? a. Because new DNA consist both strands

from parent strand b. Because new DNA consist one old and one new chain

c. Because only half of single strand is being conserved

d. Because single strand consist of okazaki fragment

23. The following are the steps in process of translation except?

a. initation b. elongation c. deletion

d. termination

24. It is a process of decoding and expressing cells genetic information. a. replication

b. transcription c. translation

d. termination 25. Why does mRNA move from nucleus to

ribosomes? a. Because it will act as template for

formation of protein b. It will act as DNA backbone c. It will transcribe amino acid

d. None of the above

26. Which of these statements best describes translocation? a. segment breaks off and flips around

backwards b. a piece of chromosome is lost

c. occurs when genes sequence is repeated d. part of one chromosome is transferred to another chromosome

27. Which of these statements best describes

inversion

a. segment breaks off and flips around backwards

b. a piece of chromosome is lost c. occurs when genes sequence is repeated

d. part of one chromosome is transferred to another chromosome

28. 1 sex chromosome is absent and only X chromosome is present, what disorder may

result a. turner’s syndrome b. albinism

c. down syndrome d. klinefelters syndrome

29. Before translocation occur two chromosomes are the same in size and

height ; After translocation, what will be the possible result?

a. they will still be the same size and height b. there will be 3 chromosomes c. both chromosomes will be taller than the

normal d. one chromosome will be shorter than the

normal and one will be taller than the normal chromosome

30. What is significant of the discovery of crick?

a. discovered the secret of life which led to further studies b. suggest the helical structure of DNA due

to X-ray crystallography c. propose the base pairing of DNA

nucleotides d. discovered the nucleic acid and identified it

31. Why did Rosalind and Maurice worked

with X-ray crystallography in their study a. to find more clues about the structure of DNA

b. to find what is its effect to human c. to find more detailed anatomical structure

d. to find more components of DNA

32. Chemical interaction of nucleotides forms phosphodiester linkages creating?

a. DNA with base pointing inward b. DNA with phosphate molecule pointing

inward c. DNA with hydrogen bonds pointing inward

d. none of the above

33.The pairing of bases in DNA through hydrogen bonding means each contains information within strand is?

a. repeated b. terminated

c. eliminated d. transferred

34. Sarah wants to construct DNA structure, what are the parts that she needs to make?

a. sugar-phosphate backbone, nitrogenous bases, hydrogen bonds b. sugar-nitrogen backbone, nitrogen bases,

ionic bonds c. sugar-phosphorous backbone, nitrogenous

bases, covalent bond d. sugar-phosphate backbone, nitrogen bases, hydrogen-oxygen bond

35. If there is 25% of adenine in DNA, what

is the percentage of uracil? a. 50% b. 25%

c. 75% d. 0%

36. Why does single strand binding proteins are needed in DNA replication?

a. it provides coordination to unwounded single strand formation

b. it provides stability to unwounded single strand formation c. it provides stability to unwounded double

strand formation d. it provides coordination to unwounded

double strand formation

37. Does the DNA replication is accurate? a. Yes, because it undergoes mechanism of

replication b. No, because it directly proceeds to

transcription c. Yes, because it undergoes mechanism of repair

d. none of the above

38. If the repressor binds to small segment of DNA, what will happen? a. there’s no mRNA produced and protein

production is inhibited b. it will change the form of mRNA

c. it will remove the mRNA d. it will begin the protein synthesis

39. Which of the following statement on tRNA is true?

a. it carries nitrogenous bases b. it combines with protein to form ribosomes

c. it carries the coding sequences from protein synthesis

d. it carries series of amino acid to ribosomes

40. Why is it that only mRNA and tRNA are involved in process that occurs in nucleus?

a. because rRNA combines with ribosomes which is located in cytoplasm b. because rRNA is located only in

cytoplasm c. rRNA carries protein in cytoplasm

d. none of the above 41. Why does the cell needs to synthesize

protein? a. for cell division processes

b. for cells growth and metabolism c. for replication processes d. for transporting genetic information

42. After the transcription process, how

many strand of DNA in a gene gets transcribed?

a. only 1 strand b. half of the strand

c. both strands d. both a and c

43. Why are UGA, UAA and UAG considered stop codons?

a. they are recognized by any tRNA molecules

b. because they are only recognized by released factors c. they are not recognized by released

factors d. none of the above

44. When does inducer should be removed? a. when there is enough protein produced

b. when protein synthesis is not needed c. when protein synthesis is needed

d. when there is no enough protein produced 45. The following statements are the way in

DNA can become mutated except a. mutation can be inherited

b. mutation can be acquired c. mutation are caused by environmental agents

d. mutation is caused by mechanism of repair

46. In what sense does mutation becomes harmless?

a. it becomes basis of species diversity of any organism

b. it creates abnormality to organism c. it produce organism which are harmless to human

d. none of the above

47. The following are the characteristics of turners syndrome except? a. tall stature

b. sterility c. sex organs don’t mature at adolescents

d. monosomy X

48. Pregnant women are not allowed to undergo X ray, what is the reason behind?

a. it can integrate virus to the fetus b. it can induce the delivery of the child

c. it is one of external agents that causes mutation d. none of the above

49. One of the results of mutation is having

sickle cell anemia, why does it is considered beneficial a. it race against other diseases

b. it provides defense against malaria c. it fights microorganism

d. it cannot be inherited 50. Ariel is in the period of adolescence, he

noticed that he develops breast enlargement, small testicles, female type of pubic hair,

what chromosomal disorder does Ariel has? a. klinefelters syndrome b. turners syndrome

c. down syndrome d. super female