Interest Grabber

1
Interest Grabber
Section 10-1

• Getting Through
• Materials move through cells by diffusion.
  Oxygen and food move into cells, while waste
  products move out of cells. How does the size of
  a cell affect how efficiently materials get to
  all parts of a cell?
• Work with a partner to complete this activity.

1. On a sheet of paper, make a drawing of a cell
that has the following dimensions 5 cm x 5 cm x
5 cm. Your partner should draw another cell about
one half the size of your cell on a separate
sheet of paper. 2. Compare your drawings. How
much longer do you think it would taketo get
from the cell membrane to the center of the big
cell than from the cell membrane to the
center of the smaller cell? 3. What is the
advantage of cells being small?
2
Section Outline
Section 10-1

• 101 Cell Growth
• A. Limits to Cell Growth
• 1. DNA Overload
• 2. Exchanging Materials
• 3. Ratio of Surface Area to Volume
• 4. Cell Division

3
Ratio of Surface Area to Volume in Cells
Section 10-1
Cell Size
Surface Area (length x width x 6)
Volume (length x width x height)
Ratio of Surface Area to Volume
4
Interest Grabber
Section 10-2

• Cell Cycle
• The cell cycle represents recurring events that
  take place in the period of time from the
  beginning of one cell division to the beginning
  of the next. In addition to cell division, the
  cell cycle includes periods when the cell is
  growing and actively producing materials it needs
  for the next division.

1. Why is the cell cycle called a cycle? 2. Why
do you think that it is important for a cell to
grow in size during its cell cycle? 3. What
might happen to a cell if all events leading up
to cell division took place as they should, but
the cell did not divide?
5
Section Outline
Section 10-2

• 102 Cell Division
• A. Chromosomes
• B. The Cell Cycle
• C. Events of the Cell Cycle
• D. Mitosis
• 1. Prophase
• 2. Metaphase
• 3. Anaphase
• 4. Telophase
• E. Cytokinesis

6
Concept Map
Section 10-2
Cell Cycle
includes
is divided into
is divided into
7
Figure 104 The Cell Cycle
Section 10-2
G1 phase
M phase
S phase
G2 phase
8
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
9
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
10
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
11
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
12
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
13
Figure 105 Mitosis and Cytokinesis
Section 10-2
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
14
Interest Grabber
Section 10-3

• Knowing When to Stop
• Suppose you had a paper cut on your finger.
  Although the cut may have bled and stung a
  little, after a few days, it will have
  disappeared, and your finger would be as good as
  new.

1. How do you think the body repairs an injury,
such as a cut on a finger? 2. How long do you
think this repair process continues? 3. What do
you think causes the cells to stop the repair
process?
15
Section Outline
Section 10-3

• 103 Regulating the Cell Cycle
• A. Controls on Cell Division
• B. Cell Cycle Regulators
• 1. Internal Regulators
• 2. External Regulators
• C. Uncontrolled Cell Growth

16
Control of Cell Division
Section 10-3
17
Figure 108 Effect of Cyclins
Section 10-3
The sample is injected into a second cell in G2
of interphase.
A sample of cytoplasm is removed from a cell in
mitosis.
As a result, the second cell enters mitosis.
18
Video Contents
Videos

• Click a hyperlink to choose a video.
• Animal Cell Mitosis
• Animal Cell Cytokinesis

19
Video 1
Video 1
Animal Cell Mitosis

• Click the image to play the video segment.

20
Video 2
Video 2
Animal Cell Cytokinesis
Click the image to play the video segment.
21
Internet
Go Online

• Links on cell growth
• Links from the authors on stem cells
• Share cell cycle lab data
• Interactive test
• For links on cell division, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-3102.
• For links on the cell cycle, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-3103.

22
Section 1 Answers
Interest Grabber Answers
1. On a sheet of paper, make a drawing of a cell
that has the following dimensions 5 cm x 5 cm x
5 cm. Your partner should draw another cell about
one half the size of your cell on a separate
sheet of paper. 2. Compare your drawings. How
much longer do you think it would taketo get
from the cell membrane to the center of the big
cell than from the cell membrane to the
center of the smaller cell? It would take twice
the amount of time. 3. What is the advantage of
cells being small? If cells are small, materials
can be distributed to all parts of the cell
quickly.
23
Section 2 Answers
Interest Grabber Answers
1. Why is the cell cycle called a cycle? It
represents recurring events. 2. Why do you think
that it is important for a cell to grow in size
during its cell cycle? If a cell did not grow in
size, each cell division would produce
progressively smaller cells. 3. What might
happen to a cell if all events leading up to cell
division took place as they should, but the cell
did not divide? Students may infer that a cell
that undergoes all sequences of the cell cycle
would grow increasingly largerto a point at
which the cell could no longer exchange materials
with the environment efficiently enough to live.
24
Section 3 Answers
Interest Grabber Answers
1. How do you think the body repairs an injury,
such as a cut on a finger? The cut is repaired
by the production of new cells through cell
division. 2. How long do you think this repair
process continues? Cell division continues until
the cut is repaired. 3. What do you think causes
the cells to stop the repair process? Students
will likely say that when the cut is filled in,
there is no room for more cells to grow.
25
How Many Chromosomes?
Interest Grabber
Section 11-4

• Normal human body cells each contain 46
  chromosomes. The cell division process that body
  cells undergo is called mitosis and produces
  daughter cells that are virtually identical to
  the parent cell. Working with a partner, discuss
  and answer the questions that follow.

26
Interest Grabber continued
Section 11-4

• 1. How many chromosomes would a sperm or an egg
  contain if either one resulted from the process
  of mitosis?
• 2. If a sperm containing 46 chromosomes fused
  with an egg containing 46 chromosomes, how many
  chromosomes would the resulting fertilized egg
  contain? Do you think this would create any
  problems in the developing embryo?
• 3. In order to produce a fertilized egg with the
  appropriate number of chromosomes (46), how many
  chromosomes should each sperm and egg have?

27
Section Outline
Section 11-4

• 114 Meiosis
• A. Chromosome Number
• B. Phases of Meiosis
• 1. Meiosis I
• 2. Meiosis II
• C. Gamete Formation
• D. Comparing Mitosis and Meiosis

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Crossing-Over
Section 11-4
29
Crossing-Over
Section 11-4
30
Crossing-Over
Section 11-4
31
Figure 11-15 Meiosis
Section 11-4
Meiosis I
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Figure 11-15 Meiosis
Section 11-4
Meiosis I
Meiosis I
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Figure 11-15 Meiosis
Section 11-4
Meiosis I
Meiosis I
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Figure 11-15 Meiosis
Section 11-4
Meiosis I
35
Figure 11-15 Meiosis
Section 11-4
Meiosis I
36
Figure 11-17 Meiosis II
Section 11-4
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter
cells, each with half the number of chromosomes
as the original.
The chromosomes line up in a similar way to the
metaphase stage of mitosis.
The sister chromatids separate and move toward
opposite ends of the cell.
Meiosis II results in four haploid (N) daughter
cells.
37
Figure 11-17 Meiosis II
Section 11-4
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter
cells, each with half the number of chromosomes
as the original.
The chromosomes line up in a similar way to the
metaphase stage of mitosis.
The sister chromatids separate and move toward
opposite ends of the cell.
Meiosis II results in four haploid (N) daughter
cells.
38
Figure 11-17 Meiosis II
Section 11-4
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter
cells, each with half the number of chromosomes
as the original.
The chromosomes line up in a similar way to the
metaphase stage of mitosis.
The sister chromatids separate and move toward
opposite ends of the cell.
Meiosis II results in four haploid (N) daughter
cells.
39
Figure 11-17 Meiosis II
Section 11-4
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter
cells, each with half the number of chromosomes
as the original.
The chromosomes line up in a similar way to the
metaphase stage of mitosis.
The sister chromatids separate and move toward
opposite ends of the cell.
Meiosis II results in four haploid (N) daughter
cells.
40
Figure 11-17 Meiosis II
Section 11-4
Meiosis II
Prophase II
Metaphase II
Anaphase II
Telophase II
Meiosis I results in two haploid (N) daughter
cells, each with half the number of chromosomes
as the original.
The chromosomes line up in a similar way to the
metaphase stage of mitosis.
The sister chromatids separate and move toward
opposite ends of the cell.
Meiosis II results in four haploid (N) daughter
cells.
41
Forever Linked?
Interest Grabber
Section 11-5

• Some genes appear to be inherited together, or
  linked. If two genes
• are found on the same chromosome, does it mean
  they are linked forever?
• Study the diagram, which shows four genes labeled
  AE and ae, and then answer the questions on the
  next slide.

42
Interest Grabber continued
Section 11-5

• 1. In how many places can crossing over result in
  genes A and b being on the same chromosome?
• 2. In how many places can crossing over result in
  genes A and c being on the same chromosome? Genes
  A and e?
• 3. How does the distance between two genes on a
  chromosome affect the chances that crossing over
  will recombine those genes?

43
Section Outline
Section 11-5

• 115 Linkage and Gene Maps
• A. Gene Linkage
• B. Gene Maps

44
Comparative Scale of a Gene Map
Section 11-5
Mapping of Earths Features
Mapping of Cells, Chromosomes, and Genes
Cell
Earth
Chromosome
Country
Chromosome fragment
State
Gene
City
People
Nucleotide base pairs
45
Video Contents
Videos

• Click a hyperlink to choose a video.
• Meiosis Overview
• Animal Cell Meiosis, Part 1
• Animal Cell Meiosis, Part 2
• Segregation of Chromosomes
• Crossing Over

46
Video 1
Video 1
Meiosis Overview

• Click the image to play the video segment.

47
Video 2
Video 2
Animal Cell Meiosis, Part 1

• Click the image to play the video segment.

48
Video 3
Video 3
Animal Cell Meiosis, Part 2

• Click the image to play the video segment.

49
Video 4
Video 4
Segregation of Chromosomes

• Click the image to play the video segment.

50
Video 5
Video 5
Crossing Over

• Click the image to play the video segment.

51
Internet
Go Online

• The latest discoveries in genetics
• Interactive test
• Articles on genetics
• For links on Punnett squares, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-4112.
• For links on Mendelian genetics, go to
  www.SciLinks.org and enter the Web Code as
  follows cbn-4113.
• For links on meiosis, go to www.SciLinks.org and
  enter the Web Code as follows cbn-4114.

52
Section 1 Answers
Interest Grabber Answers

• 1. In the first generation of each experiment,
  how do the characteristics of the offspring
  compare to the parents characteristics?
• All offspring had the same characteristic, which
  was like one of the parents. The other
  characteristic seemed to have disappeared.
• 2. How do the characteristics of the second
  generation compare to the characteristics of the
  first generation?
• Both characteristics appeared in this
  generation. The characteristic that had
  disappeared in the first generation did not
  appear as often as the other characteristic. (It
  appears about 25 percent of the time.)

53
Section 2 Answers
Interest Grabber Answers
1. Assuming that you expect 5 heads and 5 tails
in 10 tosses, how do the results of your tosses
compare? How about the results of your partners
tosses? How close was each set of results to what
was expected? Results will vary, but should be
close to 5 heads and 5 tails. 2. Add your
results to those of your partner to produce a
total of 20 tosses. Assuming that you expect 10
heads and 10 tails in 20 tosses, how close are
these results to what was expected? The results
for 20 tosses may be closer to the predicted 10
heads and 10 tails. 3. If you compiled the
results for the whole class, what results would
you expect? The results for the entire class
should be even closer to the number predicted by
the rules of probability. 4. How do the expected
results differ from the observed results? The
observed results are usually slightly different
from the expected results.
54
Section 3 Answers
Interest Grabber Answers

• 1. Make a list of 10 adults whom you know. Next
  to the name of each adult, write his or her
  approximate height in feet and inches.
• Check students answers to make sure they are
  realistic.
• 2. What can you observe about the heights of the
  ten people?
• Students should notice that there is a range of
  heights in humans.
• 3. Do you think height in humans is controlled
  by 2 alleles, as it is in pea plants? Explain
  your answer.
• No, height does not seem to be controlled by two
  alleles, as it is in pea plants. Height in humans
  can vary greatly and is not just found in tall
  and short phenotypes.

55
Section 4 Answers
Interest Grabber Answers

• 1. How many chromosomes would a sperm or an egg
  contain if either one resulted from the process
  of mitosis?
• 46 chromosomes
• 2. If a sperm containing 46 chromosomes fused
  with an egg containing 46 chromosomes, how many
  chromosomes would the resulting fertilized egg
  contain? Do you think this would create any
  problems in the developing embryo?
• 46 46 92 a developing embryo would not
  survive if it contained 92 chromosomes.
• 3. In order to produce a fertilized egg with the
  appropriate number of chromosomes (46), how many
  chromosomes should each sperm and egg have?
• Sperm and egg should each have 23 chromosomes.

56
Section 5 Answers
Interest Grabber Answers

• 1. In how many places can crossing over result in
  genes A and b being on the same chromosome?
• One (between A and B)
• 2. In how many places can crossing over result in
  genes A and c being on the same chromosome? Genes
  A and e?
• Two (between A and B and A and C) Four (between
  A and B, A and C, A and D, and A and E)
• 3. How does the distance between two genes on a
  chromosome affect the chances that crossing over
  will recombine those genes?
• The farther apart the genes are, the more likely
  they are to be recombined through crossing over.

57
Figure 11-19 Gene Map of the Fruit Fly
Section 11-5
Exact location on chromosomes
Chromosome 2
58
End of Custom Shows

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