Bio 101 exam 3

Which structure in this figure shows one complete nucleosome? 2

2

Which one of the structures shows a histone protein? 4

4

We would expect that a 15 mRNA nucleotide sequence (not including stop codon) will direct the production of a polypeptide that consists of Answers: 2 amino acids. 3 amino acids. 4 amino acids. 5 amino acids.

5 amino acids.

When one DNA molecule is copied to make two DNA molecules, the new DNA contains Answers: 75% of the parent DNA. none of the parent DNA. 50% of the parent DNA. 100% of the parent DNA

50% of the parent DNA.

Most cells spend the majority of their lives in Selected Answer:c. interphase Answers: a. mitosis b. meiosis c. interphase d. prophase

Answer: c. interphase

DNA polymerase

Adds DNA nucleotides one by one to elongate / make DNA

DNA helicase

Breaks hydrogen bonds and separates the double strands of DNA

In 1954, Hershey and Chase used radioactive isotope labeled ____________to demonstrate that DNA is the genetic material that gets passed from generation to generation. Answers: Bacteria Bacteriophages (viruses that infect bacteria) Mice Plants

Bacteriophages (viruses that infect bacteria)

The picture below shows a _____x_____ chromosome. Answers: Unduplicated Duplicated

Duplicated

Which of the following statements about eukaryotic RNA processing is false? Answers: A cap is added to one end of the RNA. A long tail of extra nucleotides is added to one end of the RNA. Exons are spliced together. Introns are added to the RNA.

Introns are added to the RNA

DNA ligase

Joins short DNA fragments to make a long one

In the middle of a long mRNA sequence, a codon changed from UAC to UAA. What will be the result for the protein product? Answers: Protein will not change . Protein will change due to frame-shift mutation Protein will change to a longer one due to single base pair substitution (point mutation) Protein will change to a shorter one due to single base pair substitution (point mutation)

Protein will change to a shorter one due to single base pair substitution (point mutation)

If a protein is made of 90 amino acids, how many mRNA bases / nucleotides (not including the stop coden) does it need to code for this protein? Answers: 90 30 180 270

Selected Answer: 270

In a double stranded DNA molecule, if A (Adenine) constitutes 21% of all the bases, what is the percentage of C (Cytosine)? Answers: 21% 29% 79% 50%

Selected Answer: 29%

The directions for each amino acid in a polypeptide are indicated by a codon that consists ofnucleotide(s) in an RNA molecule. Answers: 1 2 3 4

Selected Answer: 3

If one strand of DNA is 5'CGGTAC3', the other strand would be Answers: 5'GCCTAG3'. 3'CGGTAC5' 5'GCCATG3' 3'GCCATG5'

Selected Answer: 3'GCCATG5'

Both DNA and RNA polymerization occurs in the direction of __________. Answers: 5' to 3' 3' to 5 N-terminus to C- terminus C-terminus to N-terminus

Selected Answer: 5' to 3'

Which one of the following best describes chromosome? Answers: Chromosomes are made of DNA and histone proteins Chromosomes are densely packed Chromosomes are found in the nucleus of eukaryotic cells. All of the above.

Selected Answer: All of the above.

DNA differs from RNA in that________ . Answers: DNA is double stranded while RNA is single stranded DNA has deoxyribose sugar while RNA has ribose sugar DNA has uracil while RNA has thymine All of the above (a, b, c) Both a and b

Selected Answer: Both a and b

Which of the following options best depicts the flow of genetic information (the central dogma) when a gene directs the synthesis of a protein? Answers: RNA -- DNA -- RNA -- protein DNA -- tRNA -- mRNA -- protein DNA -- amino acid -- RNA -- protein DNA -- mRNA -- protein

Selected Answer: DNA -- mRNA -- protein

This picture shows a __________ molecule. Selected Answer: DNA nucleotide Answers: DNA nucleotide RNA nucleotide amino acid simple sugar

Selected Answer: DNA nucleotide

Mutation can be caused by the following factors except ____. Answers: replication error radiation such as UV light, X-ray environmental pollutants tobacco smoking DNA polymerase's proof reading ability

Selected Answer: DNA polymerase's proof reading ability

Transcription is a complicated process which contains the following event in the right order Answers: Elongation, initiation, and termination Initiation, termination and elongation Termination, elongation, and initiation Initiation, elongation, and termination

Selected Answer: Initiation, elongation, and termination

During DNA replication, the synthesis of one strand is continuous, this is the __________; while the synthesis of the other strand is discontinuous, this is the __________. Answers: Template strand; coding strand Coding strand; template strand Leading strand; lagging strand Lagging strand; Leading strand

Selected Answer: Leading strand; lagging strand

DNA codes specifically for ______. Answers: Proteins Carbohydrates Lipids Steroid

Selected Answer: Proteins

Which of the following enzymes catalyzes the linking together of RNA nucleotides to form RNA? Answers: a ribozyme RNA polymerase tRNA RNA ligase

Selected Answer: RNA polymerase

Which woman aided in the discovery of the structure of DNA based on her work on X-ray Crystallography? Answers: Rosalind Franklin Sheila Watson Marie Curie Maurice Wilkins

Selected Answer: Rosalind Franklin

Picture I in the above diagram shows ___oo________ in mitosis. Answers: interphase prophase metaphase anaphase Telophase

Selected Answer: Telophase

Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like a single base substitution mutation (also called point mutation)? Answers: The dog dog did not eat. The doe did not eat. The dog did not. The dog did not et.

Selected Answer: The doe did not eat.

In a coding DNA sequence, two nucleotides are deleted during replication, what would happen to the protein product? Answers: Nothing; the protein will not change. The protein will be a different protein due to single base substitution mutation. The protein will be a different protein due to frame-shift mutation. The protein will be a different protein due to missense mutation.

Selected Answer: The protein will be a different protein due to frame-shift mutation.

Which amino acid would be attached to a tRNA with the anticodon CAA? Use the genetic code chart to find the answer Answers: His Glu Gln Val

Selected Answer: Val

Which of the following people are credited with the discovery of the structure of DNA? Answers: Franklin Hershey and Chase Griffith Watson and Crick

Selected Answer: Watson and Crick

During DNA semi conservative replication, two DNA molecules are produced, Selected Answer: a and c Answers: the two molecules are genetically identical one consists of two parental strands, the other consists of two newly synthesized strands each contains one parental strand, one newly synthesized strand a and b a and c

Selected Answer: a and c

Any permanent change in the nucleotide sequence of DNA is called Answers: a codon. an anticodon. an advantage. a mutation.

Selected Answer: a mutation.

Chromosomes are copied during what stage of the cell cycle? Answers: a. S b. D c. G1 d. G2 e. M

Selected Answer: a. S

Chromatids that are attached at the centromere are called ____ chromatids. Selected Answer:a. sister Answers: a. sister b. mother c. programmed d. either mother or daughter e. daughter

Selected Answer: a. sister

Which of the following about genetic codes is false? Selected Answer: ambiguous (one codon can specify more than one amino acids) Answers: they are continuous, non-overlapping triplets they are universal (all living organism use the same set of code with very few exceptions) redundant (one amino acid can have more than one codons) unambiguous (exclusive, one codon specifies only one amino acid) ambiguous (one codon can specify more than one amino acids)

Selected Answer: ambiguous (one codon can specify more than one amino acids)

Cytokinesis in animal cells involves _____. Answers: a. the formation of evenly spread cytoskeletal elements under the entire plasma membrane b. formation of a cleavage furrow c. the division of sister chromatids d. formation of a cell plate e. the synthesis of new spindle fibers

Selected Answer: b. formation of a cleavage furrow

If we compare DNA double helix structure to a twisted ladder, then____________________. Answers: sugar-phosphate backbone make up the sides and the bases make up the rungs the two DNA strands are antiparallel and held by covalent bonds the two DNA strands are antiparallel and held by hydrogen bonds Both a and b both a and c

Selected Answer: both a and c

Malignant cells spread to other tissues in a process called Answers: a. apoptosis b. cytokinesis c. neoplasm d. metastasis

Selected Answer: d. metastasis

The chromatids detach from one another during __________________. Answers: a. interphase b. metaphase c. prophase d. anaphase e. telophase

Selected Answer: d. anaphase

The region of noncoding DNA at the end or tips of each chromosome that protects the chromosome from damage is called a____________ Answers: a. Chromosomal furrow b. Centromere c. Chromosomal plate d. Cytokinetic region e. Telomere

Selected Answer: e. Telomere

Activators can bind to ________on DNA to increase RNA transcription. Answers: repressors silencers enhancers initiators

Selected Answer: enhancers

The noncoding region in DNA is called __________, while the coding region is called ___________. Answers: exon, intron intron, exon

Selected Answer: intron, exon

In eukaryotic cells, transcription occurs in the __________, while translation occurs in the ____________. Answers: nucleus, nucleus nucleus, cytoplasm cytoplasm, nucleus cytoplasm, cytoplasm

Selected Answer: nucleus, cytoplasm

The term "gene expression" refers to the Answers: fact that DNA replicates during cell division. fact that certain genes are visible as dark stripes on a chromosome. fact that each individual of a species has a unique set of genes. process by which genetic information flows from genes to mRNAs to proteins.

Selected Answer: process by which genetic information flows from genes to mRNAs to proteins.

Transcription starts at the specific region on DNA called __________ region. Answers: promoter terminator enhancer silencer

Selected Answer: promoter

A short sequence of a template DNA is: AGC TTC .The amino acids that this segment would specify are (use the genetic code chart) Answers: lys - ser ser - lys ser - phe cys - phe

Selected Answer: ser - lys

The transfer of genetic information from DNA to mRNA is called ________ ; from mRNA to protein is called _______ . Answers: replication, translation transcription, translation transcription, replication translation, transcription

Selected Answer: transcription, translation

If a codon in mRNA has the sequence of AGC, what would be the sequence of the anticodon on the corresponding tRNA molecule? Answers: AGC TCG UCG Ser

UCG

A short sequence of a template DNA is AGC TTC, the corresponding mRNA sequence is Answers: AGC UUC TCG UUG UCG AAG TCG AAG

UCG AAG

From one gene sequence, transcription will result in one pre-mRNA transcript; through __________, it can code for more than one proteins. Answers: gene mutation alternative splicing transcription replication

alternative splicing

In mitosis, if a parent cell has 16 chromosomes, each daughter cell will have how many chromosomes? Answers a. 64 b. 16 c. 4 d. 8 e. 32

b. 16

The initiator tRNA Answers: carry methionine (Met) has an anticodon of AUG has an anticodon of UAC both a and b both a and c

both a and c

Genes that normally stimulate cell division, but which, when mutated lead to overstimulation of mitosis are called a _______. Answers: a. metastastatic genes b. cancer genes c. proto-oncogenes d. chromatids e. neoplasmic genes

c. proto-oncogenes

Genes that normally stimulate cell division, but which, when mutated lead to overstimulation of mitosis are called a _______. a. metastastatic genes b. cancer genes c. proto-oncogenes d. chromatids e. neoplasmic genes

c. proto-oncogenes

Which of the following best describes mitosis? Answers: a. divides the nucleus and doubles the chromosomal number in the daughter cells b. maintains the structure of the nucleus, cytoplasm, and chromosomes c. divides the chromosomes within the nucleus into two haploid sets d. divides the cytoplasm and doubles the chromosomal number in the daughter cells e. divides the nucleus and maintains the chromosomal number in the daughter cells

e. divides the nucleus and maintains the chromosomal number in the daughter cells

Methylation (addition of -CH3) of nucleotide does not change gene sequence but it can silence gene expressing through Answers: translational control epigenetic modification posttranslational control X-chromosome inactivation

epigenetic modification

Primase

make a short RNA primer

During translation in eukaryotic cells, ___________ . Answers: ribosomes move into the nucleus polypeptides are synthesized at ribosomes, according to instructions carried by mRNA tRNA carries amino acid molecules to the nucleus, where they are added to a polypeptide mRNA is synthesized based on the template strand of DNA

polypeptides are synthesized at ribosomes, according to instructions carried by mRNA

Many proteins are phosphorylated after synthesis in the ribosomes, this is a typical ___________ gene regulation. Answers: Transcriptional level Post-transcriptional level Translational level post-translational level

post-translational level

At the end of translation, a protein called __________binds to the stop codon and cleaves the polypeptide from the last tRNA, releasing the polypeptide. Answers: promoter transcription factor repressor release factor

release factor

Which of the following takes place during translation? Answers: the conversion of genetic information from the language of proteins to the language of enzymes the conversion of genetic information from DNA nucleotides into RNA nucleotides DNA replication the conversion of genetic information from the language of nucleic acids to the language of proteins

the conversion of genetic information from the language of nucleic acids to the language of proteins