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Unit 7 | Molecular Biology

Total questions: 45

Worksheet time: 23mins

Name
Class
Date
1.

DNA is composed of:

a)

Amino acids

b)

Fatty acids

c)

Nucleotides

d)

Glucose molecules

2.

What are the three parts of a nucleotide in DNA?

a)

a) Ribose sugar, phosphate group, nitrogenous base

b)

b) Deoxyribose sugar, phosphate group, nitrogenous base

c)

c) Amino acid, peptide bond, carboxyl group

d)

d) Glucose, fructose, sucrose

3.

The nitrogenous bases in DNA are held together by what type of bond?

a)

Covalent bonds

b)

Ionic bonds

c)

Hydrogen bonds

d)

Van der Waals forces

4.

Which of the following is a key difference in DNA replication between prokaryotes and eukaryotes, based only on DNA shape/location?

a)

Eukaryotic DNA replication is semiconservative, while prokaryotic is not.

b)

Prokaryotes have multiple origins of replication.

c)

Prokaryotic DNA is circular and located in the cytoplasm, while eukaryotic DNA is linear and resides within the nucleus.

d)

Prokaryotic DNA replication involves Okazaki fragments.

5.

DNA replication is described as a semiconservative process. What does this mean?

a)

The original DNA molecule is conserved, and a completely new molecule is synthesized.

b)

DNA replication results in three new strands and one old strand.

c)

Each new DNA molecule contains one original (old) strand and one newly synthesized strand.

d)

Portions of the original DNA molecule are dispersed within the newly synthesized molecules.

6.

During DNA replication, which enzyme is responsible for unwinding the DNA double helix at the replication fork?

a)

a) DNA polymerase

b)

b) Primase

c)

c) Helicase

d)

d) Ligase

7.

DNA polymerase synthesizes new DNA strands in which direction?

a)

3' to 5'

b)

5' to 3'

c)

Both directions simultaneously

d)

It depends on whether it is the leading or lagging strand.

8.

The lagging strand is synthesized in short fragments called

a)

Replication bubbles

b)

Primers

c)

Okazaki fragments

d)

Nucleotides

9.

What is the role of DNA ligase in DNA replication?

a)

a) To add RNA primers to the template strand.

b)

b) To unwind the DNA double helix.

c)

c) To synthesize new DNA nucleotides.

d)

d) To join the Okazaki fragments together.

10.

What is the central dogma of biology?

a)

a) Protein -> RNA -> DNA

b)

b) RNA -> DNA -> Protein

c)

c) DNA -> RNA -> Protein

d)

d) DNA -> Protein -> RNA

11.

The process of making RNA from a DNA template is called

a)

Replication

b)

Transcription

c)

Translation

d)

Mutation

12.

Which enzyme is responsible for synthesizing mRNA during transcription?

a)

a) DNA polymerase

b)

b) RNA polymerase

c)

c) Ribosome

d)

d) Ligase

13.

In transcription, which base in RNA replaces thymine (T) in DNA?

a)

Adenine (A)

b)

Guanine (G)

c)

Cytosine (C)

d)

Uracil (U)

14.

Where does transcription occur in eukaryotic cells?

a)

Cytoplasm

b)

Ribosomes

c)

Nucleus

d)

Mitochondria

15.

The coding strand of DNA has the sequence 5'-CGT-3'. What would be the corresponding codon in the mRNA transcribed from the template strand?

a)

5'-CGT-3'

b)

3'-GCA-5'

c)

5'-TAC-3'

d)

5'-GCA-3'

16.

The process of synthesizing a protein from an mRNA template is called:

a)

Replication

b)

Transcription

c)

Translation

d)

Mutation

17.

Where does translation occur in the cell?

a)

Nucleus

b)

Ribosomes in the cytoplasm or on the rough ER

c)

Mitochondria

d)

Golgi apparatus

18.

What is a codon?

a)

A sequence of two nucleotides in mRNA.

b)

A sequence of three nucleotides in mRNA that codes for an amino acid.

c)

A sequence of three nucleotides in tRNA that is complementary to mRNA.

d)

A structural component of ribosomes.

19.

Which type of RNA carries amino acids to the ribosome during translation?

a)

mRNA (messenger RNA)

b)

rRNA (ribosomal RNA)

c)

tRNA (transfer RNA)

d)

snRNA (small nuclear RNA)

20.

Multiple DNA replication events can happen simultaneously.

a)

True

b)

False

21.

DNA strands are always antiparallel to each other.

a)

True

b)

False

22.

In PCR, the primers used are made of RNA.

a)

True

b)

False

23.

Transcription starts at a random location on the DNA molecule.

a)

True

b)

False

24.

rRNA has a role in the catalytic activity of ribosomes during translation

a)

True

b)

False

25.

Who were the scientists that discovered the double helix structure of DNA?

a)

Albert Einstein and Niels Bohr

b)

Gregor Mendel and Charles Darwin

c)

Rosalind Franklin and Maurice Wilkins

d)

James Watson and Francis Crick

26.

What technique did Rosalind Franklin use to help reveal the structure of DNA?

a)

Electron microscopy

b)

X-ray crystallography

c)

Mass spectrometry

d)

Nuclear magnetic resonance

27.

Which component of DNA is responsible for carrying genetic information?

a)

Hydrogen bonds

b)

Nitrogenous bases

c)

Sugar molecules

d)

Phosphate groups

28.

Which enzyme is responsible for adding nucleotides to the growing DNA strand during replication?

a)

Helicase

b)

Ligase

c)

DNA polymerase

d)

Topoisomerase

29.

Which of the following processes involves the removal of introns from pre-mRNA?

a)

Transcription

b)

Translation

c)

Splicing

d)

Replication

30.

What is the primary function of DNA proofreading during replication?

a)

b) To correct errors in newly synthesized DNA strands

b)

d) To join Okazaki fragments

c)

a) To unwind the DNA double helix

d)

c) To synthesize RNA primers

31.

What is the function of a promoter in transcription?

a)

c) To signal the start of transcription

b)

b) To initiate the unwinding of DNA

c)

a) To terminate transcription

d)

d) To synthesize RNA primers

32.

Which of the following signals the termination of translation?

a)

Enhancer sequence

b)

Start codon

c)

Stop codon

d)

Promoter sequence

33.

What is a mutation?

a)

A method of DNA replication

b)

A type of protein synthesis

c)

A process of cell division

d)

A change in the DNA sequence

34.

Which of the following is a type of mutation that involves the insertion or deletion of a nucleotide?

a)

Point mutation

b)

Frameshift mutation

c)

Missense mutation

d)

Silent mutation

35.

Which type of mutation does not change the amino acid sequence of a protein?

a)

Frameshift mutation

b)

Missense mutation

c)

Silent mutation

d)

Nonsense mutation

36.

What is a point mutation?

a)

A mutation that duplicates a segment of DNA.

b)

A mutation that results in a premature stop codon.

c)

A mutation that changes a single nucleotide base pair in DNA.

d)

A mutation that involves the insertion or deletion of a nucleotide.

37.

What is a missense mutation?

a)

A mutation that involves the duplication of a DNA segment.

b)

A mutation that does not change the amino acid sequence.

c)

A mutation that changes one amino acid in a protein.

d)

A mutation that results in a stop codon.

38.

Which of the following techniques utilizes a heat-stable DNA polymerase originally found in Thermus aquaticus?

a)

Gel electrophoresis

b)

Polymerase Chain Reaction (PCR)

c)

DNA replication in eukaryotes

d)

Transcription

39.

In Gel electrophoresis, DNA fragments are separated based on which of the following properties?

a)

The type of nitrogenous base

b)

The sequence of nucleotides

c)

Molecular size

d)

The number of phosphate groups

40.

Primers used in PCR are typically made of:

a)

RNA

b)

Proteins

c)

DNA

d)

Amino acids

41.

Restriction enzymes, often used in biotechnology for DNA analysis, cut DNA at:

a)

Random locations

b)

Only at the ends of chromosomes

c)

Specific recognition sites

d)

Anywhere a mutation occurs

42.

PCR primers are short, single-stranded RNA sequences

a)

True

b)

False

43.

In gel electrophoresis, all DNA molecules move towards the positive electrode because of their negative charge

a)

True

b)

False

44.

Taq Polymerase is essential for PCR because it can withstand the high temperatures required to denature DNA

a)

True

b)

False

45.

Gel electrophoresis separates DNA fragments solely based on their charge

a)

True

b)

False