Here are the Unit 3 Test answers so you can correct your work.
1. C
2. B
3. C
4. D
5. D
6. A
7. C
8. B
9. B
10. C
11. J
12. H
13. C
14. I
15. D
16. K
17. A
18. G
19. B
20. E
PG 130 # 1 - 5
I wrote in the answer for 6 as I want you to study it, as I taught it in class.
1. The DNA molecule is like a ladder. The sides
are made of sugar and phosphate, and the
steps of the ladder are made of four nitrogen
bases: A (adenine), G (guanine,) C (cytosine,)
and T (thymine).
2. In the DNA molecule, A always joins with T
and G always joins with C. (In a mutation in
DNA, incorrect base pairing may occur).
3. Chromatin is the material inside the nucleus
that contains DNA and proteins. Each strand
of chromatin contains one molecule of DNA.
4. Most human cells have 46 chromosomes or 23
pairs of chromosomes.
5. (a) Genes are small pieces of DNA that store
the information to make a particular protein.
(b) The genes are located at specific places on
the chromosome.
6. In retinal cells and muscle cells, only specific
genes are “read” in each cell and so only specific
proteins are made. Your retinal cells will
read certain genes and make different proteins
than your muscle cells, and different proteins
make your cells function differently.
Pg 135
Checking Concepts
1. (a) The answer is A, the nucleus, since it contains
the genetic material to make proteins.
(b) The answer is B, the Golgi body.
(c) The structure shown in C is the chloroplast,
which traps the energy from the Sun
to make glucose. The structure shown in
D is a mitochondrion, which provides
energy for the cell by changing a sugar
called glucose into usable energy.
2.)
3. The function of genes is to store the information
to make a specific protein.
4. To transport the information for a gene out of
the nucleus, the DNA message for a specific
protein is copied into a small molecule called
ribonucleic acid (RNA), which is small enough
to leave through the nuclear pore of the
nucleus.
5. The ribosomes that manufacture proteins for
transport out of the cell are located on the
endoplasmic reticulum.
6. The function of the Golgi body is to repackage
the protein for transport out of the cell.
7. A. sugar; B. base; C. phosphate
Pg 141
1. The Spirit Bear is white because of a gene
mutation for coat colour.
2. A gene mutation is a change in the specific
order of the A, G, C, and T bases that make
up a gene.
3. Negative mutations are harmful for the organism
and reduce the probability of offspring
being produced or surviving. Neutral mutations
do not have a beneficial or negative
effect on the organism.
4. Viruses cause mutations since viruses cause
genes to be read or copied incorrectly.
5. Three examples of environmental mutagens
are: cigarette smoke, radiation from X rays,
and pollutants. In addition, certain household
chemicals may cause mutations.
Pg 146 Chapter 4 Review
1. The nucleus is like a black box because there
are still unknown processes occurring and we
are not able to see all the activity that is happening
inside the nucleus.
2. DNA is required in every cell because DNA
contains the genes that code for the proteins
the cell requires to perform its functions.
3. The DNA molecule is like a ladder with the
sides of the ladder made of sugar and phosphates
and the steps of the ladder made up of
bases. The bases pair up, with G combining
with C, and A combining with T.
4. The four bases in DNA are A (adenine), G
(guanine), T (thymine), and C (cytosine).
5. The diagram should indicate the sugars and
phosphates on the sides of the ladder and the
bases correctly paired as the steps of the ladder.
6. Some functions of proteins in cells include
enzymes speeding up chemical reactions and
hormones acting as chemical messengers. In
addition, there are structural proteins, such as
the proteins in muscle, and signalling proteins,
such as antibodies.
7. (a) The parts of the cell that are involved in
making a protein for transport out of the
cell include the nucleus, the chromosomes,
the ribosome, vesicle, the endoplasmic
reticulum, the Golgi body, the nuclear
pore, RNA, and the plasma membrane.
(b) The nucleus receives a chemical signal to
make a specific protein. The nucleus contains
the chromosomes, which contain the
DNA. On the DNA are genes that carry
the message to make a particular protein.
The gene message is copied into RNA,
which leaves the nucleus through the
nuclear pores to the ribosomes. The proteins
are made on the ribosomes. If the
ribosomes are attached to the endoplasmic
reticulum, the proteins that are made
travel through the channels in the
endoplasmic reticulum and leave the
endoplasmic reticulum in vesicles. The
vesicles carry the protein to the Golgi body
where it is repackaged. Vesicles leave the
Golgi body and carry the proteins to the
cell membrane for export out of the cell.
8. The correct sequence of DNA bases is important
because, if the base sequence is incorrect,
then the correct protein will not be made or
the protein that is made will not work correctly.
The cell will be unable to do its job
well if the proteins are not working correctly.
9. The three types of gene mutation are: (a) substitution,
where one base is put in instead of
another; (b) deletion, in which a base is
removed from the sequence; and (c) insertion,
where an additional base is put into the
sequence. Substitution is the least harmful as
the same protein may be made. In deletion
and addition, a nonsense message is created
and the correct protein will not be made.
10. Gene mutations are caused by errors in the
DNA. They can be caused by mutagens, such
as viruses, cigarette smoke, radiation from X
rays and ultraviolet light, and various kinds of
chemicals in the environment. (In the next
chapter, students will learn that mutations can
also occur during mitosis and meiosis when
the DNA is getting copied.)
11. The sequence would be TGACAACA.
12. The sequence is e, a, i, c, f, h, b, d, g.
1. C
2. B
3. C
4. D
5. D
6. A
7. C
8. B
9. B
10. C
11. J
12. H
13. C
14. I
15. D
16. K
17. A
18. G
19. B
20. E
Chapter 4 Quiz
1. C
2. D
3. B
4. A
5. D
6. B
7. A
8. D
9. C
10. B
11. D
12. C
13. F
14. E
15. A
16. B
Here are answers to some of this weeks Assignments
p. 124
1. The cell membrane separates the inside of a
cell from the outside and controls the flow of
materials in and out of the cell.
2. The cell wall is a tough, rigid structure found
in plant cells that surrounds the cell membrane.
3. An organelle is a specialized cell part that carries
out a specific function within a cell.
4. The mitochondria change the sugar glucose
into energy that the cell can use.
5. Ribosomes are the sites where proteins are
made within the cell. They can be within the
cytoplasm or attached to the endoplasmic
reticulum.
6. After proteins are made on the endoplasmic
reticulum, they travel in vesicles to the Golgi
body for further processing and packaging.
7. The function of the nucleolus is to make ribosomes.
PG 130 # 1 - 5
I wrote in the answer for 6 as I want you to study it, as I taught it in class.
1. The DNA molecule is like a ladder. The sides
are made of sugar and phosphate, and the
steps of the ladder are made of four nitrogen
bases: A (adenine), G (guanine,) C (cytosine,)
and T (thymine).
2. In the DNA molecule, A always joins with T
and G always joins with C. (In a mutation in
DNA, incorrect base pairing may occur).
3. Chromatin is the material inside the nucleus
that contains DNA and proteins. Each strand
of chromatin contains one molecule of DNA.
4. Most human cells have 46 chromosomes or 23
pairs of chromosomes.
5. (a) Genes are small pieces of DNA that store
the information to make a particular protein.
(b) The genes are located at specific places on
the chromosome.
6. In retinal cells and muscle cells, only specific
genes are “read” in each cell and so only specific
proteins are made. Your retinal cells will
read certain genes and make different proteins
than your muscle cells, and different proteins
make your cells function differently.
Pg 135
Checking Concepts
1. (a) The answer is A, the nucleus, since it contains
the genetic material to make proteins.
(b) The answer is B, the Golgi body.
(c) The structure shown in C is the chloroplast,
which traps the energy from the Sun
to make glucose. The structure shown in
D is a mitochondrion, which provides
energy for the cell by changing a sugar
called glucose into usable energy.
2.)
3. The function of genes is to store the information
to make a specific protein.
4. To transport the information for a gene out of
the nucleus, the DNA message for a specific
protein is copied into a small molecule called
ribonucleic acid (RNA), which is small enough
to leave through the nuclear pore of the
nucleus.
5. The ribosomes that manufacture proteins for
transport out of the cell are located on the
endoplasmic reticulum.
6. The function of the Golgi body is to repackage
the protein for transport out of the cell.
7. A. sugar; B. base; C. phosphate
Pg 141
1. The Spirit Bear is white because of a gene
mutation for coat colour.
2. A gene mutation is a change in the specific
order of the A, G, C, and T bases that make
up a gene.
3. Negative mutations are harmful for the organism
and reduce the probability of offspring
being produced or surviving. Neutral mutations
do not have a beneficial or negative
effect on the organism.
4. Viruses cause mutations since viruses cause
genes to be read or copied incorrectly.
5. Three examples of environmental mutagens
are: cigarette smoke, radiation from X rays,
and pollutants. In addition, certain household
chemicals may cause mutations.
Pg 146 Chapter 4 Review
1. The nucleus is like a black box because there
are still unknown processes occurring and we
are not able to see all the activity that is happening
inside the nucleus.
2. DNA is required in every cell because DNA
contains the genes that code for the proteins
the cell requires to perform its functions.
3. The DNA molecule is like a ladder with the
sides of the ladder made of sugar and phosphates
and the steps of the ladder made up of
bases. The bases pair up, with G combining
with C, and A combining with T.
4. The four bases in DNA are A (adenine), G
(guanine), T (thymine), and C (cytosine).
5. The diagram should indicate the sugars and
phosphates on the sides of the ladder and the
bases correctly paired as the steps of the ladder.
6. Some functions of proteins in cells include
enzymes speeding up chemical reactions and
hormones acting as chemical messengers. In
addition, there are structural proteins, such as
the proteins in muscle, and signalling proteins,
such as antibodies.
7. (a) The parts of the cell that are involved in
making a protein for transport out of the
cell include the nucleus, the chromosomes,
the ribosome, vesicle, the endoplasmic
reticulum, the Golgi body, the nuclear
pore, RNA, and the plasma membrane.
(b) The nucleus receives a chemical signal to
make a specific protein. The nucleus contains
the chromosomes, which contain the
DNA. On the DNA are genes that carry
the message to make a particular protein.
The gene message is copied into RNA,
which leaves the nucleus through the
nuclear pores to the ribosomes. The proteins
are made on the ribosomes. If the
ribosomes are attached to the endoplasmic
reticulum, the proteins that are made
travel through the channels in the
endoplasmic reticulum and leave the
endoplasmic reticulum in vesicles. The
vesicles carry the protein to the Golgi body
where it is repackaged. Vesicles leave the
Golgi body and carry the proteins to the
cell membrane for export out of the cell.
8. The correct sequence of DNA bases is important
because, if the base sequence is incorrect,
then the correct protein will not be made or
the protein that is made will not work correctly.
The cell will be unable to do its job
well if the proteins are not working correctly.
9. The three types of gene mutation are: (a) substitution,
where one base is put in instead of
another; (b) deletion, in which a base is
removed from the sequence; and (c) insertion,
where an additional base is put into the
sequence. Substitution is the least harmful as
the same protein may be made. In deletion
and addition, a nonsense message is created
and the correct protein will not be made.
10. Gene mutations are caused by errors in the
DNA. They can be caused by mutagens, such
as viruses, cigarette smoke, radiation from X
rays and ultraviolet light, and various kinds of
chemicals in the environment. (In the next
chapter, students will learn that mutations can
also occur during mitosis and meiosis when
the DNA is getting copied.)
11. The sequence would be TGACAACA.
12. The sequence is e, a, i, c, f, h, b, d, g.
