Students should prepare for tomorrow's final exam by going over Unit tests and Chapter quizes. Use the website, your text, tests, and previous homework assignments to help you study. You will be allowed one sheet of paper to help you as a "cheat sheet" on tomorrow's final exam. There are 3 sections, and 20 questions (or so) in each section.
You must bring a pencil! The marking machine cannot read anything other than pencil. No one leaves the room for any reason during the final exam. Go to the bathroom and get a drink before class.
Please bring your textbooks for Friday. They will be collected. If you don't bring it in, you will owe us money and the office may not pass you to the next grade without it!
Good Luck!
Here are the answers to yesterday's homework:
p. 215
1. Unique proteins and sugars on the surfaces of
eggs and sperm help in species identification.
2. The method of fertilization for land-dwelling
animals is usually internal fertilization.
3. The method of fertilization for water-dwelling
animals is usually external fertilization.
4. Pollination is the method of internal fertilization
for land-dwelling plants, where sperm is
transferred to the female productive part of
the plant.
5. Within a seed is a plant embryo and stored
food for the embryo.
Pg 223 -
1. For successful sexual reproduction to occur,
two parents of the same species are required,
and two gametes must come together for fertilization.
2. The three stages of sexual reproduction are
mating, where gametes are brought together;
fertilization, which is the union of the egg and
sperm; and development, which is a series of
mitotic and cell divisions of the zygote that
form the embryo and fetus.
3. Answers may vary. Mammals that mate in
water include whales, sea lions, sea otters, dolphins,
and seals.
4. Internal fertilization occurs when the sperm
cells are deposited inside the female’s body
where they meet the egg. Usually only one
sperm can fertilize an egg.
5. External fertilization occurs when a sperm and
egg unite outside the bodies of the parents.
6. When an egg and sperm unite, this restores
the diploid number of chromosomes. If more
than one sperm was able to fertilize the egg,
the fertilized egg would have more than the
diploid number of chromosomes. The fertilized
egg would be unable to undergo any
more cell divisions as the egg would not pass
the checkpoints because of the incorrect number
of chromosomes.
7. Water or water-containing fluid is necessary
for animals that reproduce sexually to prevent
the dehydration of the egg, sperm, and
embryo. This is not a problem in water but
does become a problem on land.
8. In plants, the pollen tube delivers the sperm to
the egg.
9. In flowering plants, the seed is enclosed in a
fruit. In cone-bearing plants, the seed is protected
within the female cone.
Pg. 232 - 233
Checking Concepts
1. Meiosis is necessary for multicellular organisms
so that the chromosome number can be
retained and so that genetic variation can
occur.
2. Meiosis II is very similar to mitosis since in
both processes sister chromatids separate.
3. At the beginning of meiosis, the parent cell is
diploid. At the end of meiosis, there are four
haploid cells.
4. The two events that produce genetic variation
are crossing over, where genetic information is
exchanged between non-sister chromatids, and
independent assortment, where there are two
possibilities for how a chromosome will sort
itself into daughter cells.
5. Crossing over is like shuffling a deck of cards
because there are many, many possibilities of
how the genetic material in a gamete will
order itself. Crossing over can occur multiple
times, like cutting the cards and shuffling a
deck of cards.
6. You are not identical to your parents or siblings
because of the reshuffling from crossing
over and independent assortment. In independent
assortment, the egg contained chromosomes
from your grandparents on your
mother’s side, and the sperm contained genetic
information from your grandparents on your
father’s side. For each chromosome in the egg,
there was a 50% chance that you inherited
your grandmother’s genetic information, 50%
that the genetic information was from your
grandfather on your mother’s side. This is true
for all 23 chromosomes, so this is 223 possibilities
just from the egg, and there would be 223
possibilities for the sperm.
7. A karyotype allows geneticists to determine
whether there has been a chromosomal mutation.
A whole chromosome could have been
deleted or added, or a piece of a chromosome
could have been added, deleted, or moved
onto another chromosome.
8. The syndrome with three chromosomes 21s
is Trisomy 21, commonly known as Down
syndrome.
9. Answers will vary as there are many ways that
students could connect these ideas. Check for
correct associations.
10. (a) Internal fertilization
(b) External fertilization
(c) External fertilization
(d) Both, since this is sexual reproduction
from the union of the egg and sperm
11. (a) The period of rapid growth rate is from
three to six months.
(b) The growth is the slowest between the
sixth and seventh month.
(c) The fastest growth rate shows the steepest
slope on the graph. The slowest growth
rate is shown in the least steep slope.
Understanding Key Ideas
12. The purpose of fertilization is to join the egg
and the sperm, to restore the diploid number
for the offspring.
13. External fertilization is suited to aquatic environments
because the eggs, sperm, and zygote
will not dry out, and the water helps disperse
the eggs and sperm.
14. A single fertilized egg grows into a multicellular
embryo by dividing millions of times by
mitosis. The cells differentiate and become
specialized to perform a particular function.
This means certain genes will now be read and
other genes will no longer be read.
15. Pollen is male sperm and therefore contains
DNA. Each species would have unique DNA
in the pollen that might help in a crime investigation.
16. (a) 1. Ectoderm; 2. mesoderm; 3. endoderm
(b) Answers may vary but should include any
one of each of the following organs.
Ectoderm: skin, nervous system; mesoderm:
kidneys, reproductive organs;
endoderm: lining of digestive system,
lungs, liver
17. Scientists prefer to use embryonic stem cells
because these cells have the potential to
become any type of cell. Teenage or adult stem
cells can become only a few different types of
cells. For example, an adult blood stem cell
could become only blood tissue, not muscle
cells or skin cells.
18. The researcher is looking at a karyotype.
By doing this analysis, the researcher can
determine if the person has a chromosome
mutation.
19. Reproductive technology has an impact on
society because it helps infertile couples to
conceive. However, the technology raises
many ethical and other questions, such as
should these technologies be free and available
to everyone, should we be selecting for
embryos, who are the biological and legal parents
of the child, and what do we do with the
unused embryos.
Chapter 6 Quiz
1. A
2. C
3. D
4. C
5. D
6. B
7. A
8. A
9. D
10. B
11. D
12. E
13. F
14. A
15. B
16. C
Wednesday, July 30, 2008
Tuesday, July 29, 2008
Pgs 161 and 165
Here are the Answers to Pg 161
p. 161
1. The four phases of mitosis are: prophase,
metaphase, anaphase, and telophase.
2. During prophase, the nucleolus disappears and
the nuclear membrane begins to break down.
The chromosomes become visible and they
attach themselves to spindle fibres at their
centromeres.
3. During cytokinesis in animal cells, the cell
membrane pinches together and the cytoplasm
divides (Figure 5.9). During cytokinesis in
plant cells, a cell plate forms across the middle
and contains material to form a new cell wall
and cell membrane (Figure 5.10).
4. The importance of checkpoints in the cell
cycle is that at these checkpoints the cell can
be stopped from growing or dividing if conditions
are unsuitable. This precise control is
important to the survival of the organism.
5. If a checkpoint protein no longer functions,
which could occur when a mutation occurs in
a gene producing the instructions for a checkpoint
protein, cell cycle control will be lost,
and this could lead to cancer.
PG 165 # 1-6
1. (a) During growth and preparation, the cell
increases in size and makes the proteins
and molecules necessary for it to function.
Some organelles begin to duplicate.
(b) During replication, the DNA copies itself.
(c) In the continued growth and preparation
phase, the cell makes materials such as proteins
and duplicates organelles such as
mitochondria and chloroplasts.
2. The steps in DNA replication are: (a) the
DNA molecule unwinds, (b) the steps of the
DNA ladder break apart to form a template,
(c) the new side forms with A pairing with T
and G pairing with C.
3. The function of mitosis is to divide the contents
of the cell’s nucleus so that each daughter
cell will have the same number and kinds of
chromosomes as the original cell.
4. Mitosis is occurring only in cells that are
preparing to divide. Some cells stay in the
growth and preparation phase for a long
period of time. For example, brain cells get
replaced every 30 to 50 years. Cells that
become worn out easily, such as stomach
lining, intestinal lining, and skin cells, undergo
mitosis more frequently. Figure 5.3 on page
152 gives examples of different cell replacement
times.
5. Spindle fibres function to guide attached chromosomes
to opposite poles of the cell as they
contract and shorten.
6. (a) A; (b) A; (c) D; (d) C, B A, D
(e) You could tell whether a cell is just entering
mitosis by observing if the chromosomes
appear duplicated like an X where
two chromatids are attached at a centromere.
The cell would be just completing
mitosis if the chromatids are single.
1. In binary fission in bacteria, there is no
nucleus. Bacteria have only one chromosome
ring, so there is no mitosis as seen in eukaryotic
cells where the nuclear membrane disappears
and the X-shaped chromosomes move to
the equator and then separate.
2. Binary fission occurs in unicellular organisms,
but budding occurs in multicellular organisms.
In budding, repeated mitosis and cell division
occurs within an area of the individual so that
a multicellular outgrowth or bud is produced.
3. Fragmentation occurs when a piece of a plant
or animal breaks away. A new organism is able
to grow from the multiplication of the cells of
the fragmented piece.
4. In plant grafting, the stem of a desired plant is
attached to another plant that already has
roots.
5. In therapeutic cloning, stem cells can be used
to replace damaged or diseased cells.
(Embryonic stem cells, as well as egg and
sperm cells, have the potential to become any
type of cell. If the nucleus of a skin cell of a
person who has a disease is removed and
inserted into an enucleated stem cell or egg
cell, the nucleus will make proteins unique to
that individual. These new cells can be chemically
induced to become the desired type of
cell, such as kidney cells. When the kidney
cells are put back into the patient, they will
not be rejected because the patient’s body recognizes
these cells as belonging to them since
the cells will be making unique molecules
coded in the DNA of the nucleus.)
p. 161
1. The four phases of mitosis are: prophase,
metaphase, anaphase, and telophase.
2. During prophase, the nucleolus disappears and
the nuclear membrane begins to break down.
The chromosomes become visible and they
attach themselves to spindle fibres at their
centromeres.
3. During cytokinesis in animal cells, the cell
membrane pinches together and the cytoplasm
divides (Figure 5.9). During cytokinesis in
plant cells, a cell plate forms across the middle
and contains material to form a new cell wall
and cell membrane (Figure 5.10).
4. The importance of checkpoints in the cell
cycle is that at these checkpoints the cell can
be stopped from growing or dividing if conditions
are unsuitable. This precise control is
important to the survival of the organism.
5. If a checkpoint protein no longer functions,
which could occur when a mutation occurs in
a gene producing the instructions for a checkpoint
protein, cell cycle control will be lost,
and this could lead to cancer.
PG 165 # 1-6
1. (a) During growth and preparation, the cell
increases in size and makes the proteins
and molecules necessary for it to function.
Some organelles begin to duplicate.
(b) During replication, the DNA copies itself.
(c) In the continued growth and preparation
phase, the cell makes materials such as proteins
and duplicates organelles such as
mitochondria and chloroplasts.
2. The steps in DNA replication are: (a) the
DNA molecule unwinds, (b) the steps of the
DNA ladder break apart to form a template,
(c) the new side forms with A pairing with T
and G pairing with C.
3. The function of mitosis is to divide the contents
of the cell’s nucleus so that each daughter
cell will have the same number and kinds of
chromosomes as the original cell.
4. Mitosis is occurring only in cells that are
preparing to divide. Some cells stay in the
growth and preparation phase for a long
period of time. For example, brain cells get
replaced every 30 to 50 years. Cells that
become worn out easily, such as stomach
lining, intestinal lining, and skin cells, undergo
mitosis more frequently. Figure 5.3 on page
152 gives examples of different cell replacement
times.
5. Spindle fibres function to guide attached chromosomes
to opposite poles of the cell as they
contract and shorten.
6. (a) A; (b) A; (c) D; (d) C, B A, D
(e) You could tell whether a cell is just entering
mitosis by observing if the chromosomes
appear duplicated like an X where
two chromatids are attached at a centromere.
The cell would be just completing
mitosis if the chromatids are single.
1. In binary fission in bacteria, there is no
nucleus. Bacteria have only one chromosome
ring, so there is no mitosis as seen in eukaryotic
cells where the nuclear membrane disappears
and the X-shaped chromosomes move to
the equator and then separate.
2. Binary fission occurs in unicellular organisms,
but budding occurs in multicellular organisms.
In budding, repeated mitosis and cell division
occurs within an area of the individual so that
a multicellular outgrowth or bud is produced.
3. Fragmentation occurs when a piece of a plant
or animal breaks away. A new organism is able
to grow from the multiplication of the cells of
the fragmented piece.
4. In plant grafting, the stem of a desired plant is
attached to another plant that already has
roots.
5. In therapeutic cloning, stem cells can be used
to replace damaged or diseased cells.
(Embryonic stem cells, as well as egg and
sperm cells, have the potential to become any
type of cell. If the nucleus of a skin cell of a
person who has a disease is removed and
inserted into an enucleated stem cell or egg
cell, the nucleus will make proteins unique to
that individual. These new cells can be chemically
induced to become the desired type of
cell, such as kidney cells. When the kidney
cells are put back into the patient, they will
not be rejected because the patient’s body recognizes
these cells as belonging to them since
the cells will be making unique molecules
coded in the DNA of the nucleus.)
Day 17 - Sexual Reproduction and Development
Today we will be discussing the differences between different methods of reproduction, i.e. internal vs. external fertilization, and reproductive technology. It should be the goal of the student that they can differentiate before tomorrows quiz on chapter 6
Advantages and disadvantages to asexual and sexual reproduction as a strategy
Different methods of asexual reproduction
Different methods of sexual reproduction
Don't forget about the final exam on Thursday!
Here is the homework due Wednesday:
Pg 215 # 1 - 5
Pg 223 # 1 - 9
Pg. 233 # 1, 2, 4, 8, 10, 12-16.
These are the answers to last day's assignments:
Pg 184 # 1-26
1. Cell division is necessary in unicellular organisms
so that these organisms can reproduce
themselves in great numbers.
2. Cell division is necessary in multicellular
organisms for growth and to replace worn-out
cells.
3. The three stages of the cell cycle are interphase,
mitosis, and cytokinesis.
4. Cells are performing the life functions of a cell
during interphase. Digestive system cells will
be making enzymes, retina cells will be performing
chemical reactions so that you are
able to see. In addition, the cell is preparing
for cell division by duplicating organelles.
5. The checkpoint proteins check for the following:
(a) Are there enough nutrients in the cell
to support growth? (b) Is the DNA damaged?
(c) Has the DNA replicated? (d) Have the
chromosomes become attached to the spindle
fibres? (e) Have the chromosomes moved to
the poles in anaphase?
6. If the cell as unable to make the proteins to
form spindle fibres, mitosis could not occur
successfully since the chromosomes would not
be able to attach. The result would be that the
chromosomes would not be equally distributed
between cells.
7. If there is a mutation in a checkpoint protein,
the cell may continue to proceed through the
cell cycle and the result is that the cell may die
or have a mutation.
8. Bacteria grow at an exponential rate through
binary fission and mutations do occur. If a
mutation occurs that allows the bacteria to
become resistant to antibiotics, these bacteria
will survive and multiply.
9. The chart should include the following:
Interphase: Cell carries out the functions necessary
for survival, and if the cell is going to
divide it will prepare for cell division by copying
the DNA and duplicating organelles.
Mitosis: The duplicated chromosomes are
divided into two equal parts.
Cytokinesis: The two nuclei and the contents
of the cell separate into two daughter cells.
10. The chart should include the following:
Prophase: The chromosomes become visible,
and the spindle fibres appear and chromosomes
attach.
Metaphase: The spindle fibres pull the Xshaped
chromosomes into a single line at the
equator.
Anaphase: The spindle fibres contract and
shorten, and the chromatids are pulled to
opposite poles of the cell.
Telophase: The spindle fibres disappear, and
the nuclear membrane forms around each set
of chromosomes.
11. The daughter plant cells will remain together
with a cell plate between them, which will
form the cell membrane and cell wall. The
animal cells will pinch completely apart.
12. The major disadvantage of asexual reproduction
is that there is very little variation so all
the offspring are identical. If conditions
change, all of the individuals could die.
13. Three reasons for human-assisted cloning are
to save an endangered species, to mass produce
an organism with a desired trait, or to
correct health problems.
14. Reproductive cloning is also known as adult
DNA cloning, and it is used to duplicate an
entire individual that has a desired trait.
15. Stem cells are cells that are not yet differentiated
to become a specific kind of cell. They
have the potential to become many different
types of cells.
16. Two characteristics of asexual reproduction are
that only one parent is required and all of the
offspring are genetic clones of the parent.
17. The nuclear membrane must disintegrate during
prophase so that the chromosomes are free
to attach to the spindle fibres.
18. (a) These cells are plant cells.
(b) You know that they are plant cells because
there appears to be a cell wall, there is no
centromere for the spindle fibres to attach
to, and the cells remain side by side after
cell division.
(c) The correct sequence is C, A, D, B.
(d) Diagram C shows prophase where the
chromosomes become visible. Diagram A
show metaphase where the chromosomes
are lined up in single file at the equator.
Diagram D shows anaphase where the
chromatids move to opposite poles.
Diagram B shows telophase where the
nuclear membrane forms around the sets
of chromosomes.
19. If the chromosomes do not separate out correctly
during anaphase, the cell will probably
not pass the checkpoints to go through the
rest of the cell cycle. The cell will die, or it
may go unchecked so that one daughter cell
will end up with more chromosomes than the
other daughter cell.
20. Cancer cells spread to a new location when
they break away and move into the bloodstream,
where they may begin to divide and
form a new tumour.
21. The blood vessels branch into the tumour and
deliver nutrients to it, which allows it to grow
even more rapidly.
22. A laboratory technician can identify cancer
cells because these cells have a large abnormal
nucleus since there are extra chromosomes
inside.
23. Only less complex forms of life can reproduce
asexually because lower forms have only a few
types of cells. Higher forms have many types
of specialized cells to form complex tissues.
24. There are concerns about stem cell research
because some people feel it is wrong to
destroy cells that are able to develop into an
individual.
25. To determine the best conditions for reproduction
of an amoeba, the scientist might put
the amoeba in different environments such as
more light, less light, warmer temperatures,
colder temperatures, more acidic, or less
acidic. The conditions that produced the
fastest rate of growth without any mutations
would be the ideal conditions.
p. 194
1. Genetic diversity is the inherited differences in
a population. For example, not everyone in the
classroom is the same height.
2. The function of meiosis is to reduce the chromosome
number so that when the egg and
sperm unite the original number of chromosomes
will not be doubled.
3. (a) The haploid number of chromosomes in
humans is 23.
(b) The diploid number of chromosomes in
humans is 46.
4. Another name for a fertilized egg is a zygote.
5. Homologous chromosomes are a matching
pair of chromosomes that are the same size
and shape. They have genes coding for the
same trait in the same location. (One member
of the pair originally came from the mother’s
egg and the other from the father’s sperm).
Pg 203
1. The number of chromosomes in a human skin
cell is 46 (the diploid number) and in a human
egg cell is 23 (the haploid number).
2. To identify a pair of homologous chromosomes,
you would look for two chromosomes
that have the same size and shape.
3. The benefits of genetic diversity are that
organisms may have new characteristics that
allow them to be better equipped to cope with
changes in the environment. The organism
may gain an advantage over another organism.
4. For a zygote to become an embryo, the cell
must undergo mitosis and cell division.
5. (a) Meiosis II
(b) Meiosis I
(c) Meiosis I
(d) Meiosis I
(e) Meiosis II
6. Cannot be uploaded at this time. Mr. Gill is working on a solution.
7. In meiosis I, the homologous chromosomes
are paired at the equator. In mitosis, the
homologous chromosomes are unpaired and
line up individually at the equator.
8. There is the diploid number (46 chromosomes
in humans) in metaphase of mitosis and the
haploid number (23 chromosomes or 46 chromatids
in humans) in metaphase II of meiosis.
9. In crossing over, parts of non-sister chromatids
exchange information that could create
new characteristics.
10. In independent assortment, there are two possibilities
of how a chromosome will sort itself
into the daughter cells. This is true for each of
the 23 pairs, so this leads to many possible
combinations.
11. Examples of chromosome mutations can
include the loss of a whole chromosome, or
part of a chromosome, the duplication of a
chromosome, or the movement of a piece of
the chromosome within itself or to another
chromosome. Students might mention fruit fly
mutations here as well.
12. Examples of genetic disorders illustrated in the
text include: Down syndrome and Edwards
syndrome.
Advantages and disadvantages to asexual and sexual reproduction as a strategy
Different methods of asexual reproduction
Different methods of sexual reproduction
What is the difference between mitosis and meiosis?
How are mitosis and meiosis similar?
Can you describe Interphase, Mitosis, and Cytokenesis in 10 seconds each? What about 5 seconds each? What about 2?
Don't forget about the final exam on Thursday!
Here is the homework due Wednesday:
Pg 215 # 1 - 5
Pg 223 # 1 - 9
Pg. 233 # 1, 2, 4, 8, 10, 12-16.
These are the answers to last day's assignments:
Pg 184 # 1-26
1. Cell division is necessary in unicellular organisms
so that these organisms can reproduce
themselves in great numbers.
2. Cell division is necessary in multicellular
organisms for growth and to replace worn-out
cells.
3. The three stages of the cell cycle are interphase,
mitosis, and cytokinesis.
4. Cells are performing the life functions of a cell
during interphase. Digestive system cells will
be making enzymes, retina cells will be performing
chemical reactions so that you are
able to see. In addition, the cell is preparing
for cell division by duplicating organelles.
5. The checkpoint proteins check for the following:
(a) Are there enough nutrients in the cell
to support growth? (b) Is the DNA damaged?
(c) Has the DNA replicated? (d) Have the
chromosomes become attached to the spindle
fibres? (e) Have the chromosomes moved to
the poles in anaphase?
6. If the cell as unable to make the proteins to
form spindle fibres, mitosis could not occur
successfully since the chromosomes would not
be able to attach. The result would be that the
chromosomes would not be equally distributed
between cells.
7. If there is a mutation in a checkpoint protein,
the cell may continue to proceed through the
cell cycle and the result is that the cell may die
or have a mutation.
8. Bacteria grow at an exponential rate through
binary fission and mutations do occur. If a
mutation occurs that allows the bacteria to
become resistant to antibiotics, these bacteria
will survive and multiply.
9. The chart should include the following:
Interphase: Cell carries out the functions necessary
for survival, and if the cell is going to
divide it will prepare for cell division by copying
the DNA and duplicating organelles.
Mitosis: The duplicated chromosomes are
divided into two equal parts.
Cytokinesis: The two nuclei and the contents
of the cell separate into two daughter cells.
10. The chart should include the following:
Prophase: The chromosomes become visible,
and the spindle fibres appear and chromosomes
attach.
Metaphase: The spindle fibres pull the Xshaped
chromosomes into a single line at the
equator.
Anaphase: The spindle fibres contract and
shorten, and the chromatids are pulled to
opposite poles of the cell.
Telophase: The spindle fibres disappear, and
the nuclear membrane forms around each set
of chromosomes.
11. The daughter plant cells will remain together
with a cell plate between them, which will
form the cell membrane and cell wall. The
animal cells will pinch completely apart.
12. The major disadvantage of asexual reproduction
is that there is very little variation so all
the offspring are identical. If conditions
change, all of the individuals could die.
13. Three reasons for human-assisted cloning are
to save an endangered species, to mass produce
an organism with a desired trait, or to
correct health problems.
14. Reproductive cloning is also known as adult
DNA cloning, and it is used to duplicate an
entire individual that has a desired trait.
15. Stem cells are cells that are not yet differentiated
to become a specific kind of cell. They
have the potential to become many different
types of cells.
16. Two characteristics of asexual reproduction are
that only one parent is required and all of the
offspring are genetic clones of the parent.
17. The nuclear membrane must disintegrate during
prophase so that the chromosomes are free
to attach to the spindle fibres.
18. (a) These cells are plant cells.
(b) You know that they are plant cells because
there appears to be a cell wall, there is no
centromere for the spindle fibres to attach
to, and the cells remain side by side after
cell division.
(c) The correct sequence is C, A, D, B.
(d) Diagram C shows prophase where the
chromosomes become visible. Diagram A
show metaphase where the chromosomes
are lined up in single file at the equator.
Diagram D shows anaphase where the
chromatids move to opposite poles.
Diagram B shows telophase where the
nuclear membrane forms around the sets
of chromosomes.
19. If the chromosomes do not separate out correctly
during anaphase, the cell will probably
not pass the checkpoints to go through the
rest of the cell cycle. The cell will die, or it
may go unchecked so that one daughter cell
will end up with more chromosomes than the
other daughter cell.
20. Cancer cells spread to a new location when
they break away and move into the bloodstream,
where they may begin to divide and
form a new tumour.
21. The blood vessels branch into the tumour and
deliver nutrients to it, which allows it to grow
even more rapidly.
22. A laboratory technician can identify cancer
cells because these cells have a large abnormal
nucleus since there are extra chromosomes
inside.
23. Only less complex forms of life can reproduce
asexually because lower forms have only a few
types of cells. Higher forms have many types
of specialized cells to form complex tissues.
24. There are concerns about stem cell research
because some people feel it is wrong to
destroy cells that are able to develop into an
individual.
25. To determine the best conditions for reproduction
of an amoeba, the scientist might put
the amoeba in different environments such as
more light, less light, warmer temperatures,
colder temperatures, more acidic, or less
acidic. The conditions that produced the
fastest rate of growth without any mutations
would be the ideal conditions.
p. 194
1. Genetic diversity is the inherited differences in
a population. For example, not everyone in the
classroom is the same height.
2. The function of meiosis is to reduce the chromosome
number so that when the egg and
sperm unite the original number of chromosomes
will not be doubled.
3. (a) The haploid number of chromosomes in
humans is 23.
(b) The diploid number of chromosomes in
humans is 46.
4. Another name for a fertilized egg is a zygote.
5. Homologous chromosomes are a matching
pair of chromosomes that are the same size
and shape. They have genes coding for the
same trait in the same location. (One member
of the pair originally came from the mother’s
egg and the other from the father’s sperm).
Pg 203
1. The number of chromosomes in a human skin
cell is 46 (the diploid number) and in a human
egg cell is 23 (the haploid number).
2. To identify a pair of homologous chromosomes,
you would look for two chromosomes
that have the same size and shape.
3. The benefits of genetic diversity are that
organisms may have new characteristics that
allow them to be better equipped to cope with
changes in the environment. The organism
may gain an advantage over another organism.
4. For a zygote to become an embryo, the cell
must undergo mitosis and cell division.
5. (a) Meiosis II
(b) Meiosis I
(c) Meiosis I
(d) Meiosis I
(e) Meiosis II
6. Cannot be uploaded at this time. Mr. Gill is working on a solution.
7. In meiosis I, the homologous chromosomes
are paired at the equator. In mitosis, the
homologous chromosomes are unpaired and
line up individually at the equator.
8. There is the diploid number (46 chromosomes
in humans) in metaphase of mitosis and the
haploid number (23 chromosomes or 46 chromatids
in humans) in metaphase II of meiosis.
9. In crossing over, parts of non-sister chromatids
exchange information that could create
new characteristics.
10. In independent assortment, there are two possibilities
of how a chromosome will sort itself
into the daughter cells. This is true for each of
the 23 pairs, so this leads to many possible
combinations.
11. Examples of chromosome mutations can
include the loss of a whole chromosome, or
part of a chromosome, the duplication of a
chromosome, or the movement of a piece of
the chromosome within itself or to another
chromosome. Students might mention fruit fly
mutations here as well.
12. Examples of genetic disorders illustrated in the
text include: Down syndrome and Edwards
syndrome.
Monday, July 28, 2008
Day 16 - Asexual and Sexual Reproduction
Keep going, guys! Only 5 days and counting! I just marked the homework, and I must say for the most part it was not very good. Many people seem to be putting in very little effort towards completing all their answers. I want to encourage you to complete all answers. In the event your test and quiz scores are borderline passing, I will be looking at your homework records to judge whether or not you have achieved a good enough understanding to pass. Homework is very important for your studies. DO YOUR HOMEWORK!
Here are the answers to the Chapter 4 Quiz
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 is the homework for tonight:
Pg 194 # 1 - 5
Pg 203 # 1 - 12
Here are the answers to the Chapter 5 Quiz Questions:
Chapter 5 Quiz
1. D
2. D
3. D
4. B
5. A
6. B
7. D
8. A
9. D
10. D
11. D
12. A
13. F
14. C
15. B
16. E
Here are the answers to the Chapter 4 Quiz
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 is the homework for tonight:
Pg 194 # 1 - 5
Pg 203 # 1 - 12
Here are the answers to the Chapter 5 Quiz Questions:
Chapter 5 Quiz
1. D
2. D
3. D
4. B
5. A
6. B
7. D
8. A
9. D
10. D
11. D
12. A
13. F
14. C
15. B
16. E
Friday, July 25, 2008
Movies! - Mitosis and Meiosis
Here is a great movie that teaches about Mitosis:
This is a good movie on Meiosis:
And another video on Meiosis:
Hope this helps! Study hard - 5 school days left!
This is a good movie on Meiosis:
And another video on Meiosis:
Hope this helps! Study hard - 5 school days left!
Answers to Unit 3 Test and Assignments from Week 3
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.
Day 15 - Cell Reproduction - Mitosis and Mieosis
Friday July 24th.
Here we are on the last big push!
This weekend I want to encourage all students to study chapter 5 for their quiz on Monday. They should also be reviewing their chapter quizes and assignments, as well as their unit tests for the final exam Thursday.
We will first hand back and enter results from the worksheet on Ohm's law to close out our work on Electricity. We will then go over the results for the Unit 1 test, and go over the individual answers. This is important as I will be using Unit Tests and Chapter Quizzes to create the bulk of the questions for the Comprehensive Final Exam. Today we will be going over and answering one at a time the questions from the chapter review on page 184, questions # 1-10. The students will then complete Chapter 5 Review on Pg 184 - # 11 - 26 as their ticket out the door. This will be crucial for them to succeed on the Chapter 5 quiz on Monday.
This is a good online description and quiz of mitosis and meiosis.
Here is a great video on Mitosis
And this is Meiosis. How are these two processes similar? Can you find some differences between the two?
Here is how next week looks:
Monday -Chapter 5 Quiz complete work on chapter 6
Tuesday - Mark work on Chapter 6 and prepare for Unit Test on Biology
Wednesday - Unit Test on Biology - Prepare for Final Exam
Thursday - Final Exam - Begin Astronomy (2 assignments likely)
Friday Finish Astronomy and hand in.
These are the assignments due Monday
Here we are on the last big push!
This weekend I want to encourage all students to study chapter 5 for their quiz on Monday. They should also be reviewing their chapter quizes and assignments, as well as their unit tests for the final exam Thursday.
We will first hand back and enter results from the worksheet on Ohm's law to close out our work on Electricity. We will then go over the results for the Unit 1 test, and go over the individual answers. This is important as I will be using Unit Tests and Chapter Quizzes to create the bulk of the questions for the Comprehensive Final Exam. Today we will be going over and answering one at a time the questions from the chapter review on page 184, questions # 1-10. The students will then complete Chapter 5 Review on Pg 184 - # 11 - 26 as their ticket out the door. This will be crucial for them to succeed on the Chapter 5 quiz on Monday.
This is a good online description and quiz of mitosis and meiosis.
Here is a great video on Mitosis
And this is Meiosis. How are these two processes similar? Can you find some differences between the two?
Here is how next week looks:
Monday -Chapter 5 Quiz complete work on chapter 6
Tuesday - Mark work on Chapter 6 and prepare for Unit Test on Biology
Wednesday - Unit Test on Biology - Prepare for Final Exam
Thursday - Final Exam - Begin Astronomy (2 assignments likely)
Friday Finish Astronomy and hand in.
These are the assignments due Monday
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