10.1 Limits to Cell Size Name:

Biology 6.0 Date: Period:

The Story of the Three Cells

One reason cells are small is that, as they grow, their volume increases faster than their surface area. Before starting take a moment to think about what problem this causes the cell? Once upon a time there was a family of three cells. There was baby, momma and poppa cell. They all lived together in the town of human body, however there was a problem. Momma and Poppa cell could never find enough food to be full, but baby cell for some reason was always fine.

Use a surface area to volume ratio to explain this problem. Here are some formulas to remember:Volume =

Surface Area =

Ratio is found when Surface Area is divided by Volume

Calculate the Volume, Surface Area and Ratio using the given measurements. Baby Cell Momma Cell Poppa Cell

L = 1mm, H = 1mm, W = 1mm L = 3mm, H = 3mm, W = 3mm L = 9mm, H = 9mm, W = 9mmVolume = Volume = Volume =

Surface area = Surface area = Surface area =

Surface area to volume ratio = Surface area to volume ratio = Surface area to volume ratio =

1. Which cell has the greatest volume?2. Which cell has the smallest volume?3. Which cell has the greatest surface area?4. Which cell has the smallest surface area?5. Which cell has the greatest surface area to volume ratio?6. How many small cubes do you think it would take to fill the medium cube?7. What would the surface area be if L = 2cm, W = 3cm and H = 7cm?8. What is the volume of a cube with sides L = 3cm, W = 2cm, and H = 7cm?

© Pearson Biology 1

Why are cells so small?

Think about this: even though a whale is much larger than a human and a human is much larger than a tulip, their cells are all roughly the same size. Whales donʼt have larger cells than humans, just more of them.

There is a very specific reason why cells are the size they are. Anytime this cell interacts with its environment, it does so at its membrane. The more membrane a cell has, the more exchange it can perform with its environment. (This exchange can include activities such as obtaining nutrients or getting rid of wastes.) We refer to the amount of surface that an object has as its surface area (SA).

Once materials get inside the cell, they move via diffusion. Diffusion is the random movement of particles that results in their dispersion in the cytoplasm. A drop of food coloring in a beaker of water will diffuse until the entire beaker is the same color. This type of movement occurs inside cells as a way of dispersing molecules. Diffusion works best over short distances. Imagine how long it would take food coloring molecules to diffuse in a water glass vs. in a swimming pool. Because the water glass has less volume (V), diffusion is more efficient.

Cells try to maximize their surface area (in order to improve exchange) and minimize their volume (to make diffusion more efficient). A basketball-sized cell would have lots of surface area (good), but also lots of volume (bad). Think about how long it would take molecules to diffuse from the outer portion of the ball to the center. A ping-pong ball or a marble would be better choices. When we discuss the interplay of these two quantities, we use the ratio of surface area to volume (abbreviated SA/V). Ideal cells have large SA values, but small V values.

Instructions:First, look at the photos of the cells. These are very young embryos from sea urchins, marine organisms that you may have seen in nature documentaries or possibly along a rocky coastline. These photos were taken over a span of 105 minutes, beginning immediately after fertilization (Panel 1). The fertilized egg then divided once (Panel 3) to produce a two cell embryo (Panel 4), and then again (Panel 5) to produce a 4-cell embryo (Panel 6).

Eventually, hundreds of divisions would result in a tiny sea urchin larva that would settle to the sea bed and grow into a mature urchin (see photo to right).

Embryonic cells such as these are convenient to use as models for cell size because they are nearly perfect spheres.

9. To maintain life, and carry out cellular functions, materials must be able to move into and out of the cell. Also, material needs to be able to move within the cell. What might be the advantage of having a large surface area?

10. What might be the disadvantage of having a large volume?

© Pearson Biology 2

11. Explain how a small change in cell size can have a huge impact on the cell and its normal functions.

12. So why are cells so small?

© Pearson Biology 3

10.1 Cell Growth, Division, and Reproduction Name:

Biology Date: Period:

Limits to Cell SizeFor Questions 1–4, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true. 1. As a cell’s size increases, its amount of DNA also increases.

2. The amount of activity in a cell is related to its volume.

3. The smaller the cell, the smaller its ratio of surface area to volume.

4. The information crisis in a cell is solved by the replication of the DNA before cell division.

5. In the visual analogy of the growing town, what does the library represent? Identify two characteristics that make it a good choice for this analogy.

6. How does the analogy of a cell to a town help you understand why cells divide?

The chart below shows key terms from the lesson with their definitions. Complete the chart by writing a strategy to help you remember the meaning of each term. One has been done for you.

Term Definition

A cell divides into two new daughter cells

Reproduction involving only one parent organism

Reproduction in which cells from two different parents join to form a new organism

© Pearson Biology 4

Cell Division and Reproduction

7. is the formation of new individuals.

8. For single-celled organisms, cell division is a form of reproduction.

9. Most multicellular organisms reproduce by reproduction.

10. Vascular tissue helps plants transport water against the force of gravity. Because of this, plants that lack vascular tissue do not grow very tall. How is this situation similar to the information you have learned in this lesson? Explain.

A T-chart is a way to organize information. One way to make a T-chart is to write the textbook headings in the left column of the chart. Rewrite these headings as questions in the right column. Then, as you read, answer the question in your own words. As you read the lesson, complete the T-chart.

Headings Questions and Answers

© Pearson Biology 5

Limits to Cell Size

Cell Growth and Reproduction

Why are cells limited in size?

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

Why are cell division and reproduction important?

_______________________________________________________________

_______________________________________________________________

_______________________________________________________________

© Pearson Biology 6

Venn Diagram In the space where the circles overlap, write the features that the topics share. In the space where the circles do not overlap, write the features that are unique to each topic. Complete the Venn diagram below to compare asexual and sexual reproduction.

Asexual Sexual

Limits to Cell Size - Ratio of Surface Area to Volume

1. Draw a line from the edge of Circle A to the dot in the center

of Circle A. Do the same with Circle B. Which line looks

longer?

2. Look at the triangles in each circle. Suppose they have to move to the dot in the center. (Assume the

triangles are traveling at the same speed.) Which triangles would get to the center faster—those in Circle A

or those in Circle B? Explain your reasoning.

3. Imagine that Circle A and Circle B are cells. The triangles are materials the cells need to move in or out, or

exchange. Which cell would have a greater problem exchanging materials? Explain your

reasoning.

© Pearson Biology 7

© Pearson Biology 8

10.2 The Process of Cell Division Name:

Biology Date: Period:

ChromosomesFor Questions 1–5, complete each statement by writing the correct word or words.1. Cells carry genetic information in packages of DNA called .

2. Most have only one circular strand of DNA.

3. In eukaryotic cells, the genetic structure consists of DNA and a tightly wound protein, which together form

a substance called .

4. The beadlike structures formed by DNA wrapped around proteins are called

nucleosomes.

5. _________________________ make possible the precise separation of DNA during cell division.

The chart below shows key terms from the lesson with their definitions. Complete the chart by writing a strategy to help you remember the meaning of each term. One has been done for you.

Term Definition

Series of events a cell goes through as it grows and divides

Area where two sister chromatids are attached.

One of two identical “sister” parts of a replicated chromosome

A combination of DNA and protein found in eukaryotic cells

Made up of DNA; contains the genetic information needed to make new cells and carry out cell functions

Part of the eukaryotic cell cycle during which the cytoplasm divides

Long period of the cell cycle between one cell division and the next

Part of the eukaryotic cell cycle during which the nucleus divides

© Pearson Biology 9

The Prokaryotic Cell Cycle

The diagram on the left shows how a prokaryotic cell divides. The stages of cell division are shown in order they happen. Use the flowchart on the right to describe the steps in prokaryotic cell division. In a flowchart, arrows connect one step to the next. Write the stages in prokaryotic cell division in order in the flowchart.

Cell Division Flowchart

6. The process of cell division in prokaryotic cells is called .

7. Will the new cells have the same genetic material as the parent cell, or will each cell have different genetic

material?

8. Is this asexual or sexual reproduction?

9. An example of an organism that reproduces with this kind of reproduction is aa) salamander. b) histone. c) red blood

cell.d) bacterium.

The Cell Cycle

10. What happens during interphase?

11. Complete the cell cycle diagram by writing the correct name of a phase on each line.a. Color the phase in which most cell

growth occurs blue.b. Color the phase in which DNA

replication occurs red.c. Color the phase in which preparation for

mitosis occurs yellow.d. Color the phase in which mitosis and

cytokinesis occur orange.© Pearson Biology 10

Before division, the DNA forms one circle.DNA

Cell membrane

12. Which three phases make up interphase?

13. The division of the cell nucleus during the M phase of the cell cycle is called

14. In eukaryotic cells, what happens in the G1 phase that differs from the G2 phase?

15. In eukaryotic cells, what are the two main stages of cell division?

16. Match the process with the correct phase. S A. Cells do most of their growing.

G2 B. Chromosomes are replicated, and the synthesis of DNA molecules takes place

G1 C. Many of the organelles and molecules required for cell division are produced.

Mitosis is the process by which the nucleus of most eukaryotic cells divides. Mitosis has four phases: prophase, metaphase, anaphase, and telophase.

1. Label the four phases of mitosis in the diagram.2. Label the spindles and centrioles in one of the phases.3. Color each chromosome in prophase a different color. Follow each of these chromosomes through

mitosis. Show this by coloring the correct structures in each phase of mitosis.

© Pearson Biology 11

Chromatin

Chromosome

Interphase

Cytokinesis

17. In which phase do the chromosomes line up in the middle of the cell?

18. In which phase do the chromosomes become visible?

19. In which phase do the chromosomes move until they form two groups near the poles of the spindles?

20. During prophase, when cell chromosomes become visible, what are the duplicated strands of DNA called? What is the name for the area in which these duplicated strands are joined?

21. What structures are spindle fibers attached to that help pull the paired chromosomes apart?

Event

_________22. The chromosomes separate and begin to move to opposite sides of the cell.

_________23. The chromosomes become visible. The centrioles take up positions on opposite sides of the nucleus.

_________24. A nuclear envelope re-forms around each cluster of chromosomes. The nucleolus becomes visible in each daughter nucleus.

_________25. The chromosomes line up across the center of the cell.

Phase of Mitosis

A. Telophase

B. Prophase

C. Metaphase

D. Anaphase

26. The four circles below represent the nucleus of a cell going through mitosis. Draw four chromosomes as they go through each phase. Label each phase and describe what is happening to the DNA.

© Pearson Biology 12

© Pearson Biology 13

Cytokinesis

27. What is cytokinesis?

28. Use the Venn diagram to compare and contrast cytokinesis in animal cells with cytokinesis in plant cells.

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CytokinesisPlant Cell

BothAnimal Cell

10.3 Regulating the Cell Cycle Name:

Biology 6.0 Date: Period:

Lesson Objectives Describe how the cell cycle is regulated. Explain how cancer cells are different from other cells.

Lesson SummaryControls on Cell Division - Dozens of proteins regulate the cell cycle. Cyclins are proteins that regulate the timing of the cell cycle in eukaryotic cells. Regulatory proteins work both inside and outside of the cell.

o Internal regulators allow the cell cycle to proceed when certain events have occurred within a cell.o External regulators called growth factors stimulate the cell cycle. Other external regulators cause the cell cycle to slow

down or stop. Apoptosis is programmed cell death that plays a key role in the development of tissues and organs.Cancer: Uncontrolled Cell Growth Cancer is a disorder in which cells divide uncontrollably, forming a mass of cells called a tumor. Cancers are caused by defects in genes that regulate cell growth. Treatments for cancer include:

o removal of cancerous tumors.o radiation, which interferes with the copying of DNA in multiplying cancer cells. o chemotherapy, which is the use of chemicals to kill cancer cells.

Controls on Cell DivisionWrite True if the statement is true. If the statement is false, change the underlined word or words to make the statement true.______________1. Cells tend to continue dividing when they come into contact with other cells.

______________2. Cell division speeds up when the healing process nears completion.

______________3. Proteins called growth factors regulate the timing of the cell cycle in eukaryotic cells.

______________4. If chromosomes have not attached to spindle fibers during metaphase, an internal regulatory protein will prevent the cell from entering anaphase.

______________5. Growth factors are external regulatory proteins that slow down the cell cycle.

______________6. Once apoptosis is triggered, a cell proceeds to self-destruct.

Complete the cause-and-effect chart by giving an example of an effect caused by each type of regulatory protein.

Factors Affecting the Cell CycleCause Effect

Cyclins

Internal regulatory proteins

External regulatory proteins

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Cancer: Uncontrolled Cell Growth1.2.3.4.5.6.

7. What is cancer?

8. What are the two basic types of tumors? Explain how they are different.

9. What is the cause of cancer?

10. Fill out the flowchart by completing each statement with the correct word or words.

11. Hair grows from hair follicles, pockets of continually dividing cells in the outer layer of the skin. New cells are added to the base of a hair shaft, inside each follicle. Use what you have learned in this lesson to explain why cancer patients often lose their hair when receiving chemotherapy and grow more hair after chemotherapy stops.

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Cancer cells form tumors in other tissues by metastasis.

Cancer cells may break loose and throughout the body.

Cancer cells form a mass of cells called a .

Cancer cells do not respond to signals that regulate cell .

11.4 Meiosis Name:

Biology Date: Period:

BUILD Vocabulary - The chart below shows key terms from the lesson with their definitions. Complete the chart by writing a strategy to help you remember the meaning of each term. One has been done for you.

Term Definition

Crossing-over Exchange of DNA by the chromatids in a tetrad

Two sets of chromosomes, one from each parent

One set of chromosomes

Chromosomes in which one set comes from the female parent and one from the male parent

Cell division in which gametes are produced

A set of four chromatids formed by two pairs of replicated chromosomes

Cell produced by the union of egg and sperm

Compare/Contrast - make a compare/contrast table to show the differences between mitosis and meiosis. Use the terms or phrases to complete the compare/contrast chart. Write the terms or phrases in the correct column.

Mitosis Meiosis

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Produces body cells Crossing-over occurs Yields four haploid cellsProduces gametes Involves two cell divisions Yields two diploid cells Tetrads are formed

Phases of Meiosis - During meiosis, haploid gametes are produced from diploid cells. At the end of meiosis, the number of chromosomes in gametes is half the number of chromosomes in body cells.

Draw two homologous pairs of chromosomes (in different colors) in these diagrams to illustrate what happens during these three phases of meiosis. Do NOT leave this blank!!

1. Identify which phase of meiosis is shown in the diagrams below.

2. What does the diagram on the right show?

3. During what phase of meiosis does this process occur?

4. What is the result of this process?

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Comparing Meiosis and Mitosis - Complete the table to compare meiosis and mitosis.

Mitosis Meiosis

5. Form of reproduction

6. Number of daughter cells

7. Change in chromosome number

8. Number of cell divisions

9. Difference in alleles between parent cell and daughter cells

For the following questions, complete each statement by writing the correct word or words. Circle the correct answer.10. A diploid cell that enters mitosis with 16 chromosomes will divide to produce 1 / 2 / 4 daughter cells.

Each of these daughter cells will have 8 / 16 / 32 chromosomes.

11. If the diploid number of chromosomes for an organism is 16, each daughter cell after mitosis will contain

8 / 16 / 32 chromosomes.

12. A diploid cell that enters meiosis with 16 chromosomes will pass through 1 / 2 / 4 cell divisions,

producing 2 / 4 / 8 / 16 daughter cells, each with 8 / 16 / 32 chromosomes.

13. Gametes have a diploid / haploid number of chromosomes.

14. If an organism’s haploid number is 5, its diploid number is 2.5 / 5 / 10 .

15. While a haploid number of chromosomes may be even or odd, a diploid number is always .

16. Suppose an organism’s heart cells have 10 chromosomes. How many chromosomes will its egg cells have?

5 / 10 / 20 How many chromosomes do its sperm cells have? 5 / 10 / 20

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Chromosome Number - For the following questions, write True if the statement is true. If the statement is false, change the underlined word to make the statement true.________________ 1.________________ 2.________________ 3.________________ 4.________________ 5.________________ 6.________________ 7.________________ 8.________________ 9.________________ 10.________________ 11.________________ 12.________________ 13.________________ 14.________________ 15.________________ 16.________________ 17. The offspring of two parents obtains a single copy of every gene from each parent.

________________ 18. A gamete must contain one complete set of genes.

________________ 19. Genes are located at specific positions on spindles.

________________ 20. A pair of corresponding chromosomes is homozygous.

________________ 21. One member of each homologous chromosome pair comes from each gene.

________________ 22. A cell that contains both sets of homologous chromosomes is haploid.

________________ 23. The gametes of sexually reproducing organisms are haploid.

________________ 24. If an organism’s haploid number is 6, its diploid number is 3.

Phases of Meiosis - On the lines provided, identify the stage of meiosis I or meiosis II in which the event described occurs. Be specific, not just meiosis I or II.

________________ 25. Each replicated chromosome pairs with its corresponding homologous chromosome.

________________ 26. Crossing-over occurs between tetrads.20

________________ 27. Paired homologous chromosomes line up across the center of the cell.

________________ 28. Spindle fibers pull each homologous chromosome pair toward an opposite end of the cell.

________________ 29. A nuclear membrane forms around each cluster of chromosomes and cytokinesis follows, forming two new cells.

________________ 30. Chromosomes consist of two chromatids, but they do not pair to form tetrads.

________________ 31. A nuclear membrane forms around each cluster of chromosomes and cytokinesis follows, forming four new cells.

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Cell Division and Meiosis Review Name:

Biology Date: ________________ Period: _______

Word Bank: match the following terms to the descriptions below (write the word on the line provided)

Prophase Interphase Telophase Metaphase Anaphase

Cytokinesis G1 phase S phase G2 phase Tetrad

Crossing over Gametes Haploid Diploid

1. _____________________ The sister chromatids begin to move apart to opposite sides of the cell.

2. _____________________ The nucleolus begins to fade from view.

3. _____________________ A new nuclear membrane is forming around the chromosomes.

4. _____________________ The cytoplasm of the cell is being divided.

5. _____________________ The chromosomes become invisible.

6. _____________________ The chromosomes are lined up across the middle of the cell.

7. _____________________ The nuclear membrane begins to fade from view.

8. _____________________ The cleavage furrow appears.

9. _____________________ The chromatids are at opposite poles of the cell and begin to uncoil.

10. _____________________ The spindle is formed.

11. _____________________ The period of growth between mitotic divisions.

12. _____________________ The cell plate is complete.

13. _____________________ Chromosomes are replicated.

14. _____________________ Chromosomes begin to uncoil.

15. _____________________ The reverse of prophase.

16. _____________________ The organization (preparation) phase.

17. _____________________ The phase of the cell cycle characterized by a non-dividing cell.

18. _____________________ Chromosomes become visible, centrioles position on opposite sides of nucleus.

19. _____________________ Nucleolus becomes visible in each new daughter nucleus.

20. _____________________ Two sets of chromosomes

21. _____________________ Another name for the sperm and egg

22. _____________________ Structure formed by two homologous chromosomes (XX)

23. _____________________ One set of chromosomes

24. _____________________ Chromatids exchange segments of DNA

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Word Bank: match the following terms to the descriptions below (write the word on the line provided)

Anaphase Cell cycle Centrioles Centromere Chromatid Chromatin

Chromosome Cytokinesis Histone Interphase Metaphase Mitosis

Nucleosomes Prophase Spindle fibers Telophase

25. ____________________ The beadlike structures formed by DNA and histone molecules.

26. ____________________ Mesh-like structure that helps move the chromosomes apart.

27. ____________________ Process by which the cell nucleus is divided.

28. ____________________ First and longest phase of mitosis.

29. ____________________ Phase of mitosis in which the chromosomes start to uncoil.

30. ____________________ Material that makes up chromosomes.

31. ____________________ Phase of mitosis where sister chromatids separate.

32. ____________________ Protein around which the chromosomal DNA is coiled.

33. ____________________ Process in which the cytoplasm divides.

34. ____________________ Period of the cell cycle between divisions.

35. ____________________ Phase of mitosis in which chromosomes line up along the equator of a cell.

36. ____________________ Each chromosome consists of two of these at the beginning of mitosis.

37. ____________________ Microtubule-containing structures located near the nucleus during prophase

(animal organelle involved in cell division).

38. Name the two stages of cell division: ____________________ ____________________

39. The M phase is also known as ______________________.

40. Each pair of chromatids is attached at an area called the ________________________.

41. The three phases of ___________________________ are G1, S, and G2.

42. The ___________________________ is a series of events that cells go through as they divide and grow.

43. The beadlike structures formed by DNA wrapped around molecules (proteins)

are called nucleosomes.

44. In eukaryotic cells, the genetic structure consists of coils and supercoils of nucleosomes which together

form .

45. The ______________________ is a fanlike microtubule structure that helps separate the chromosomes.

46. ____________________________ is the division of the nucleus.

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Multiple Choice

______47. What process ensures that each daughter cell gets a complete set of genetic information and that each daughter cell also has an increased surface area?

a. meiosis c. cytokinesisb. mitosis d. cancer

______48. Before cell division, each chromosome consists of two identical “sister”a. centromeres c. chromatidsb. cell cycles d. spindles

______49. What phase of mitosis takes the longest period of time?a. prophase c. anaphaseb. cytokinesis d. interphase

______50. During cell division, the DNA in a eukaryotic cell is tightly packed and coiled into structures calleda. centromeres c. haploidsb. histones d. chromosomes

______51. Between cell divisions, the DNA in a eukaryotic cell is uncoiled and spread out. In this form it is called

a. chromatid c. histoneb. chromatin d. nonhistone

______52. If an organism has a diploid, or 2N, number of 16, how many chromosomes do its sperm cells or egg cells contain?

a. 8 b. 16 c. 32 d. 64

______53. Prokaryotic cells reproduce by a process called a. mitosis c. binary fission b. meiosis d. binary fusion

______54. In eukaryotic cells, DNA is copied during a phase of the cell cycle called a. M phase c. G1 phase b. S phase d. G2 phase

______55. During crossing over, portions of chromatids a. double the amount of DNA in each chromosome b. move from autosomes to sex chromosomes c. break off and attach to adjacent chromatids on homologous chromosomes d. separate from each other and move to opposite poles of the cell

______56. In which phase of meiosis do tetrads form? a. Prophase I c. Metaphase II b. Telophase I d. Anaphase II

______57. In oogenesis, a diploid reproductive cell divides meiotically to produce a. one diploid gamete c. one haploid gamete b. four diploid gametes d. four haploid gametes

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Distinguish between each pair of terms.

58. asexual reproduction, sexual reproduction:

59. centromere, chromatid:

60. diploid, haploid:

61. binary fission, mitosis:

62. Distinguish between the following terms: chromatid, chromatin, centromere, and chromosome.

Use the terms mitosis and meiosis to answer the following questions.

63. ____________________ Four new cells are formed from each original

64. ____________________ This process makes gametes (egg and sperm)

65. ____________________ Two new cells are produced from each original

66. ____________________ New skin cells are made this way

67. ____________________ This type of reproduction helps you grow

68. ____________________ This makes cells with half the original chromosome number

69. ____________________ This makes cells with the same chromosome number as the original.

Use the terms sperm, egg, or both sperm and egg to answer the following questions.

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70. ____________________ Formed by meiosis

71. ____________________ Formed by male

72. ____________________ Formed by female

73. ____________________ Needed for fertilization

74. ____________________ Four formed from original cell

75. ____________________ Human kind has 23 chromosomes

76. Make a T chart and identify three differences between mitosis and meiosis.

77. Why are cells limited in size?

Diagrams78. In the spaces provided, label each figure in MITOSIS.

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Phases of Meiosis

79. The stages of meiosis below are NOT in order. What is the correct order of the pictures?

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Label the phases of meiosis. Include I and II in the name.

Name of Phase (these do not correspond with the

pictures above)

Description(these do not correspond with the pictures above)

1. Homologous chromosomes pair up and form tetrad

2. Spindle fibers move homologous chromosomes to opposite sides

3. Nuclear membrane reforms, cytoplasm divides, 4 daughter cells formed

4. Chromosomes line up along equator, not in homologous pairs

5. Crossing-over occurs

6. Chromatids separate

7. Homologous chromosomes line up alone equator

8. Cytoplasm divides, 2 daughter cells are formed

Biology Keystone Exam PreparationCell Division

1. Which row in the chart below indicates the correct process for each event indicated?

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A. Row 1 B. Row 2 C. Row 3 D. Row 4

2. Asexual reproduction produces offspring that each containA. genetic information from one parentB. genetic information from two parentsC. less genetic information than either parentD. a unique combination of genetic information

3. The diagram below represents division of a cell that produces two daughter cells.

Which statement most likely describes the daughter cells produced?A. The daughter cells will pass only half of the genetic information they received from the original cell.B. The daughter cells will each produce offspring that will have the same genetic information as the

original cell.C. The daughter cells will undergo the same mutations as the original cell after reproduction has

occurred.D. The daughter cells will not pass on any of the genes that they received from the original cell.

4. The sorting and recombining of genes during meiosis and fertilization usually leads to the production of A. gametes with many copies of the same chromosomeB. embryos with traits identical to those of all other members of the speciesC. zygotes with the genetic information to produce only femalesD. offspring with some traits that did not appear in their parents

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5. Which statement concerning the reproductive cells in the diagram below is correct?

A. The cells are produced by mitosis and contain all the genetic information of the father.B. If one of these cells fertilizes an egg, the offspring will be identical to the father.C. Each of these cells contains only half the genetic information necessary for the formation of an

offspring.D. An egg fertilized by one of these cells will develop into a female with the same characteristics as the

mother.

6. A species that lacks the variation necessary to adapt to a changing environment is more likely to A. develop many mutated cellsB. become extinct over time C. begin to reproduce sexuallyD. develop resistance to diseases

7. The cell in the diagram below illustrates a stage of mitotic cell division. Letter B indicates the

A. paired chromosomesB. centriolesC. cell plateD. endoplasmic reticulum

8. A particular species of shark normally reproduces sexually. In captivity, it was found that a female could also reproduce asexually. One negative result from asexual reproduction is

A. increased gene recombination. B. increased number of males produced.C. decreased number of eggs used.D. decreased biodiversity within the species.

9. An example of sexual reproduction isA. regeneration in starfish B. spore formation in mushroomsC. fusion of nuclei of gametesD. development of new plants from undifferentiated tissue

10. In human females, how many egg cells are formed as a result of one primary sex cell undergoing normal meiotic cell division?

A. 1 B. 2 C. 3 D. 4

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11. The diagram below represents a change in composition of homologous chromosomes during synapsis.

This change is most likely the result of the process of A. nondisjunction C. crossing overB. gene linkage D. polyploidy

12. A sequence of events associated with ecosystem stability is represented below.

The arrows in this sequence should be read asA. leads to C. preventsC. reduces D. simplifies

13. Patau syndrome can be a lethal genetic disorder in mammals, resulting from chromosomes failing to separate during meiosis.

A. Identify the step during the process of meiosis when chromosomes would most likely fail to separate.

B. Describe how chromosome separation in meiosis is different from chromosome separation in mitosis.

C. Compare the effects of a disorder caused by chromosomes failing to separate during meiosis, such as Patau

syndrome, to the effects of chromosomes failing to separate during mitosis.

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