AnswersBiology AUnit Test

Unit Test — Unit test Answers

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1
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Which of these is the primary site of protein synthesis?

A
mitochondria
B
cytoplasm
C
nucleus
D
ribosomes
2
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All of the following would be visible on a karyotype except

A
aneuploidy.
B
polysomy.
C
trisomy.
D
histones.
3

How many genes make up the human genome?

A
four: adenine, thymine, guanine, and cytosine
B
23 pairs of genes
C
20,000–25,000 genes
D
3 billion genes
4

Which best matches a type of genetic material with its description?

A
Nucleotides form a helical structure that is called a gene.
B
Genes combine to form structures called nucleotides.
C
Chromosomes create genes.
D
DNA is located in the nucleus.
5

Which best summarizes the process of protein synthesis?

A
RNA instructs DNA to make proteins.
B
DNA unzips, resulting in the formation of two protein molecules.
C
RNA moves the DNA code to the ribosomes for protein synthesis.
D
DNA makes proteins in the nucleus.
6

Maria is concerned because she has been exposed to a small amount of radiation during an X-ray. What is her doctor most likely to tell her?

A
Radiations from X-rays is not a mutagen.
B
Mutagens have no effect on the body unless you have inherited them.
C
Small amounts of a mutagen often do not have an effect on health.
D
Severe mutations are usually caused by small amounts of a mutagen.
7

Karyotypes can be studied to determine an organism’s chromosomal makeup and to detect genetic defects. Down syndrome is a genetic disorder that is also called trisomy 21. What would trisomy 21 look like in a karyotype?

A
missing chromosome 21
B
extra chromosome 21
C
missing sex chromosome
D
extra sex chromosome
8

What can a person do to limit exposure to X-rays?

A
wear sunblock
B
avoid cigarette smoke
C
wear a protective lead vest
D
avoid chemicals
9

James is working with the lac operon of Escherichia coli (E. coli). He places the bacteria on a plate of growth media. Based on the current understanding of this operon, which hypothesis would be useful for James to test?

Question illustration
A
Addition of allolactose (inducer) to the bacterial growth media should increase the speed at which the bacteria metabolize the sugar lactose.
B
Removal of the RNA polymerase molecule should increase the amount of bacterial growth on the plate.
C
Decreasing the amount of allolactose (inducer) in the bacterial growth media should increase the rate of bacterial growth.
D
Increasing the rate at which RNA polymerase acts will inhibit bacterial growth.
10

What must occur for protein translation to begin?

A
A water molecule must be added to the protein chain.
B
A peptide bond must form between subunits of mRNA.
C
The amino acid Cys must be picked up by tRNA.
D
The codon AUG must be identified.
11

Which is a purpose for which a pedigree chart might be prepared?

A
to determine the gender of a fetus
B
to determine if a fetus has the correct number of chromosomes
C
to identify chromosomal defects
D
to identify the pattern of inheritance of a particular trait
12

Which is a frameshift mutation?

A
substitution
B
nonsense
C
silent
D
deletion
13

Which best describes a centromere?

A
sister chromosomes that are held together by a chromatid
B
paired chromosomes that have genes arranged in the same order
C
the part of a chromosome that joins the sister chromatids
D
the material that makes up a chromosome
14

What was Friedrich Miescher's contribution to the discovery of the genetic code?

A
He created the first photograph of the structure of DNA.
B
He discovered how the DNA bases pair together.
C
He created the first accurate model of DNA's structure.
D
He extracted and observed DNA from white blood cells.
15

Many different types of mutations can occur within the body. Cystic fibrosis is a genetic disorder that is caused by different mutations within the CFTR gene. One mutation in the CFTR gene that leads to cystic fibrosis causes translation to end earlier in the gene sequence. Which type of mutation causes this translation error that leads to cystic fibrosis?

A
silent
B
missense
C
nonsense
D
deletion
16

A forensic scientist is trying to find out the number of adenine bases in the DNA sample that he obtained from a crime scene.What can he assume about the number of adenine?

A
The number of adenine bases will be equal to the number of guanine bases.
B
The number of adenine bases will be equal to the total of all the other bases.
C
The number of adenine bases will be equal to the number of thymine bases.
D
The number of adenine bases will be half of the number of cytosine bases.
17

Which of the following correctly organizes these genetic terms in order from smallest to largest?

A
chromosome, gene, nucleotide, DNA molecule
B
nucleotide, gene, DNA molecule, chromosome
C
DNA molecule, nucleotide, gene, chromosome
D
DNA molecule, nucleotide, chromosome, gene
18

Which is an arrangement of genes consisting of an operator, a promoter, and a repressor?

A
RNA polymerase
B
anticodon
C
codon
D
operon
19

Which describes something that occurs during translation?

A
A DNA template is used to create an mRNA strand.
B
A tRNA template is used to create a DNA strand.
C
A tRNA template is used to create an mRNA strand.
D
An mRNA template is used to create an amino acid chain.
20

Which represents a strand of RNA bases?

A
CAAGGTCTC
B
AGGTTCACA
C
CAAGGUCUC
D
TGGAACTCA

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