Experiment 4 Exercise 1 – Mitosis in a Plant Cell

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How to Proceed

  • Read through the introductory materials below.
  • Open the Unit 4 Experiment Answer Sheet and complete the following Experiment exercises this unit:
    • Experiment 4 Exercise 1 – Mitosis in a Plant Cell (~45 min)
    • Experiment 4 Exercise 2 – Meiosis (~30 min)
    • Experiment 4 Exercise 3 – Karyotyping (~60 min)
  • Save your completed Unit 4 Experiment Answer Sheet and submit it no later than Sunday midnight (CT).

Mitosis – Introduction

The life cycle of a typical cell is roughly divided into two phases, Interphase and Cell Division. Interphase is a time of growth and synthesis and is further divided in to G1, S and G2 stages. G stands for “growth”. During G1, the cell grows and makes materials needed to replicate its DNA. DNA is then replicated during the S or “synthesis” phase. Additional growth occurs during G2 as the cell prepares for cell division. Cell division encompasses both nuclear division (Mitosis) and cytoplasm division (Cytokinesis). See Fig 8.6 on p 125 in your book.

Mitosis allows cells in our body to regenerate (e.g., replacement of shed skin cells) and to repair damaged tissue, since mitosis produces daughter cells that are identical to the parent cell. Before beginning this exercise, you will want to review Mitosis in our online lecture and examine the diagrams in Fig 8.7 on pp 126-127 and Fig 8.8 on p 128, which illustrates some differences between animal and plant cells. As you can see, each phase of the cell cycle can be recognized based on the appearance the chromosomes and nucleus. In this first exercise, you will need to be able to identify the various phases of the cell in onion cells. Below is an example of what you will be looking at:

Phases of the cell in onion cells

From: Ackroyd, Miller and Sauriol. No date. Mitotic cell division in onion root tip, Allium cepa.

Slide # Phase Description
1-2 Interphase Chromosomes are not visible in the nucleus (gray circle).
3-5 Prophase Chromosomes have become visible; although not apparent, the nuclear membrane is breaking down.
6 Metaphase Chromosomes have aligned along the equator (mid-line).
7-8 Anaphase Sister chromatids have separated and are being pulled to opposite poles.
9-10 Telophase Chromosomes are clumped at opposite poles, the nucleus has reformed and a cell plate is forming.

Note that is hard to determine exactly when one phase ends and the next one starts. Slide #7, for example is early anaphase and could also be considered late metaphase. Slide #9 is early telophase, but might also be considered late anaphase.

See your Unit 4 Experiment Answer Sheet for the instructions and the photographs you will use to complete this exercise.

Meiosis – Introduction

Meiosis is the process by which gametes (eggs and sperm) are produced from a germ cell. This type of cell division is unlike mitosis in that the cells produced are genetically different than the parent cell and the resulting cells contain only half the number of chromosomes (haploid). In this exercise, you will need to demonstrate your understanding of Meiosis and the role it plays in sexually reproducing organisms. Review this unit’s reading in your book (pp 131-141) and this unit’s online lecture before completing this exercise. You will need to review the following animation, so be sure that you are able to open and view it:

McGraw-Hill Higher Education. 2006. How Meiosis Works
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter28/animation__how_meiosis_works.html (Links to an external site.)

When you are ready, open the Unit 4 Experiment Answer Sheet and answer the questions for this exercise.

Karyotyping – Introduction

Review pp 130-121, pp 138-140 and our online lecture this unit before beginning this exercise. Many genetic disorders arise as a result of errors during Meiosis and the formation of gametes (= egg and sperm). Frequently, these errors are due to non-disjunction, in which chromosomes fail to separate correctly during Anaphase. When this happens, a daughter cell ends up with either an extra chromosome or it is missing a chromosome. These genetic disorders can be detecting using a screening process called a karyotype. In this exercise, you will learn how a karyotype is generated and used to diagnose the presence or absence of a disorder.

You will use the following website to complete this exercise:

The Biology Project. 1998. Karyotyping Activity
http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html  V

WEEK 4 EXPERIMENT ANSWER SHEET Please submit to the Week 4 Experiment dropbox no later than Sunday midnight.

SUMMARY OF ACTIVITIES FOR WEEK 4 EXPERIMENT ASSIGNMENT

· Experiment 4 Exercise 1 –Mitosis in a Plant Cell

· Experiment 4 Exercise 2 – Meiosis

· Experiment 4 Exercise 3 – Karyotyping

Experiment 4 Exercise 1: Mitosis in a Plant Cell

Read through the Experiment 4 Introduction material before starting. In this exercise we will look at the different stages of mitosis in onion cells. The length of the cell cycle in the onion root tip is about 24 hours, but mitosis only occupies only one to two hours.

Procedure

A. Review the information on p 125 in your book and record your predictions as to the percentage of cells you expect to see in each of the phases of the cell cycle in Table 1 (after the photographs).

B. In the four photographs below, examine each cell indicated by a red dot. There are a total of 65 cells that need to be examined. Determine how many cells are in the various stages of the Cell Cycle. Refer to your book and the Experiment 4 Introduction information for help determining the cell cycle stages.

C. Enter your data in Table 1. Note that the “Calculated %” is equal to the Number of cells in stage / Total cells counted x 100.

D. Answer the questions that follow.

image1.png

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Table 1: Predictions and actual number of cells observed in each stage of the cell cycle (2 pts)

Stage Predicted % Number of Cells Total Cells Counted Calculated %
Interphase     65  
Prophase     65  
Metaphase     65  
Anaphase     65  
Telophase     65  
Total 100% 65 65 100%

Questions

1. What stage of the cell cycle were most of the onion root tip cells in (1 pts)?

Is this what you would expect based on what you’ve read this week; why or why not? Cite source(s) used (1 pts).

2. How accurate were your predictions, based on your data, for each stage of the cell cycle (1 pts)?

3. What is the function of mitosis in an organism such as a human? Cite source(s) used (2 pts).

Experiment 4 Exercise 2: Meiosis

Review this week’s reading in your book (pp 131-141) and this week’s online lecture. Then view the following animation before answering the questions below; be sure your audio is on:

McGraw-Hill Higher Education. 2006. How Meiosis Works http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter28/animation__how_meiosis_works.html

Questions

1. Why is it necessary to reduce the chromosome number in gamete cells (egg and sperm), but not other cells of an organism? Cite source(s) used (2 pts).

2. Describe at least two differences between Meiosis I and Meiosis II in terms of what is produced and what occurs with the chromosomes. Cite source(s) used (2 pts).

3. If humans have 46 chromosomes in each of their body cells, determine how many chromosomes you would expect to find in the following cells (4 pts):

Sperm _________

Liver cell _________

Daughter cell from mitosis _________

Daughter cell from Meiosis II _________

4. _____ are separated during Meiosis I, while _____ are separated during Meiosis II (2 pts).

a. Sister chromatids, sex chromosomes

b. Sister chromatids, homologous chromosomes

c. Homologous chromosomes, sister chromatids

d. Sex chromosomes, sister chromatids

5. At the beginning of meiosis I, cells are ____ and at the beginning of meiosis II, they are ____ (2 pts).

a. Diploid, diploid

b. Diploid, haploid

c. Haploid, haploid

d. Haploid, diploid

Experiment 4 Exercise 3: Karyotyping

Go to the following website:

The Biology Project. 1998. Karyotyping Activity

http://www.biology.arizona.edu/human_bio/activities/karyotyping/karyotyping.html

Procedure

A. Read over the material on the first page and then click on Patient Histories (at the bottom of the page).

B. Click on Complete Patient A’s Karyotype. Note a single chromosome located to the left of the paragraph at the top. You need to match this chromosome with the appropriate pair.

a. Some of the chromosomes arranged beneath the paragraph are hyperlinked (have a blue line beneath them).

b. Click on the hyperlink associated with the matching chromosome.

C. Record in Table 2 below the correct match for this first chromosome (a).

D. Continue until you have matched all chromosomes required. Note that the letters (a-e) correspond to the order that the chromosomes are presented.

Table 2. Patient A karyotype data (1 pts).

Chromosome Presented Matches #
Chromosome a  
Chromosome b  
Chromosome c  
Chromosome d  
Chromosome e  

Questions

1. What notation would you use to characterize Patient A’s karyotype? Be sure to read over the information presented so you know the correct notation format (1 pts).

2. Based on the table of possible chromosomal disorders displayed on the website, what diagnosis would you give patient A (1 pts)?

3. When during Meiosis does the error occur that results in this karyotype; be specific (1 pts)?

 

Procedure (continued)

E. Click on the Patient History button (bottom of the page) and then click on Complete Patient B’s Karyotype.

F. Match the chromosomes presented as done in the previous exercise.

G. Fill in the Table 3 below, indicating how you matched up the chromosomes presented with the actual chromosomes in the karyotype.

Table 3. Patient B karyotype data (1 pts).

Chromosome Presented Matches #
Chromosome a  
Chromosome b  
Chromosome c  
Chromosome d  
Chromosome e  
Chromosome f  
Chromosome g  
Chromosome h (This is a tough one)  

Questions

4. What notation would you use to characterize Patient B’s karyotype (1 pts)?

5. What diagnosis would you give patient B (1 pts)?

6. Why does this individual exhibit male characteristics and not female? Cite your source (2 pts).

 

Procedure (continued)

H. Click on the Patient History button (at the bottom) and then click on Complete Patient C’s Karyotype.

I. Match the chromosomes presented as done in the previous exercise.

J. Fill in Table 4 below, indicating how you matched up the chromosomes presented with the actual chromosomes in the karyotype.

Table 4. Patient C karyotype data (2 pts).

Chromosome Presented Matches #
Chromosome a  
Chromosome b  
Chromosome c  
Chromosome d  
Chromosome e  
Chromosome f  
Chromosome g  
Chromosome h  
Chromosome i  

Questions

7. What notation would you use to characterize Patient B’s karyotype (1 pts)?

8. What diagnosis would you give patient C (1 pts)?

9. Why might the risk of this disorder increase as a woman gets older? Cite any sources used (3 pts).

 

Week 4 Experiment Grading Rubric

Component Expectation Points
Experiment 4 Exercise 1 Distinguishes among the various stages of the cell cycle and correctly answers the questions (Table 1, Questions 1-3). 7 pts
Experiment 4 Exercise 2 Demonstrates an understanding of meiosis and how it relates to sexual reproduction (Questions 1-6). 12 pts
Experiment 4 Exercise 3 Creates and uses a karyotype to diagnose genetic disorders (Tables 2, 3, and 4; Questions 1-9). 16 pts
TOTAL  
 
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Which of the following is true of a diploid organism?

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Question 1
Select one answer.
10 points
Which of these discusses genotypes rather than phenotypes.
1.     The offspring of these flowers can be either red or white.
2.     The male mouse is homozygous dominant.
3.     Lactose intolerance can be due to a missing protein (the enzyme that digests lactose).
4.     All of these discuss genotypes
Question 2
Select one answer.
10 points
Alleles are different versions of a _______________.
1.     phenotype
2.     chromosome
3.     gene
4.     genotype
Question 3
Select one answer.
10 points
Which of the following is true of a diploid organism?
1.     It has two of each gene.
2.     It has two of each chromosome.
3.     It has two alleles of each gene.
4.     All of the above.
5.     None of the above.
Question 4
Select one answer.
10 points
The sister chromatids separate during which stage of meiosis?
1.     Anaphase I
2.     Anaphase II
3.     Prophase I
4.     Prophase II
Question 5
Select one answer.
10 points
The next three questions are based on the following information.
In humans, the ability to roll the tongue (T) is dominant over the inability to do so (t). Suppose Mike, who can roll his tongue, and Jeannie, who cannot roll her tongue, have a child, Benjamin.
Part 1 of 3: If Mike’s mother was able to roll her tongue but his father was not able to roll his, then what is the probability that Benjamin will be able to roll his tongue?
1.     100%
2.     75%
3.     50%
4.     0%
Question 6
Select one answer.
10 points
Part 2 of 3: What is the probability that Benjamin will be homozygous recessive?
1.     50%
2.     0%
3.     75%
4.     100%
Question 7
Select one answer.
10 points
Part 3 of 3: What is the probability that Benjamin will be homozygous dominant?
1.     0%
2.     50%
3.     100%
4.     75%
Question 8
Select one answer.
10 points
How many different gametes are produced by a cell with the genotype AABb?
1.     1
2.     2
3.     3
4.     4
Question 9
Select one answer.
10 points
Describe the importance of independent assortment: ________________________.
1.     will assort independently of each other
2.     will sort to the same gamete
3.     are called alleles
4.     All of these are true
Question 10
Select one answer.
10 points
Homozygous is a term that can describe a(n) _____________.
1.     allele
2.     heterozygous
3.     genotype
4.     phenotype

Question 11
Select one answer.
10 points
Red flower color is incompletely dominant over white flower color. If a red flower is crossed with a pink flower, what percentage of the offspring will be pink?
1.     100%
2.     75%
3.     50%
4.     25%
Question 12
Select one answer.
10 points
Use the following information to answer the next three questions.
In humans, there are three alleles for blood type: A, B, and O. A and B are codominant over O. Suppose Jim, a man with type A blood, and Leah, a woman with type B blood, have a child, Winnie. Jim’s parents both have blood type AB. Leah’s mother has type B, and her father has type O.
Part 1 of 3: What is the probability that Winnie’s blood type will be AB?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 13
Select one answer.
10 points
Part 2 of 3:What is the chance that Winnie’s blood type will be A?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 14
Select one answer.
10 points
Part 3 of 3:What is the chance that Winnie’s blood type will be B?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 15
Select one answer.
10 points
Use the following information to answer the next three questions.
In dogs, colored fur, E, is dominant over colorless fur, e. Black fur color, B, is dominant over brown fur color, b. The E gene is epistatic to the B gene. Suppose a yellow male dog is mated with a black female. The male’s parents were both brown. The female’s mother was yellow, and her father was brown.
Part 1 of 3: What percentage of the puppies will be yellow?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 16
Select one answer.
10 points
Part 2 of 3: What percentage of the puppies will be black?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 17
Select one answer.
10 points
Part 3 of 3: What percentage of the puppies will be brown?
1.     100%
2.     75%
3.     50%
4.     25%
5.     0%
Question 18
Select one answer.
10 points
Human height is affected by ______________.
1.     genetics only
2.     the environment only
3.     genetics and the environment

Question 19

Select one answer.
10 points
A genetic disorder that is sex-linked cannot also be ___________________.
1.     autosomal
2.     recessive
3.     dominant
4.     all of these are possible
Question 20
Select one answer.
10 points
In humans, how many alleles of genes found on the X chromosome do male have?
1.     0
2.     1
3.     2
4.     4
Question 21

Select one answer.
10 points
Nondisjunction in meiosis I results in
1.     two cells missing a chromosome and two healthy cells.
2.     two cells missing a chromosome and two cells with an additional chromosome
3.     one cell missing a chromosome, one cell with missing a chromosome and two healthy cells.
4.     two cells with an additional chromosome and two healthy cells
Question 22

Select one answer.
10 points
Sickle cell anemia is an autosomal recessive disorder. A person with the disorder and a person that is a carrier mate. (A carrier has the allele for the trait but does not express it.)
What is the chance that their offspring will develop sickle cell anemia?
1.     100%
2.     75%
3.     50%
4.     25%
Question 23

Select one answer.
10 points
The sex of the offspring is determined by _____________.
1.     the mother only
2.     the father only
3.     both the mother and the father
Question 24

Select one answer.
10 points
According to the pedigree below, this trait is ____________________.

1.     Sex-linked recessive
2.     autosomal dominant
3.     Sex-linked dominant
4.     autosomal recessive
Question 25

Select one answer.
10 points
What is the genotype of the unshaded individuals in the pedigree below?

1.     Either AA or Aa
2.     Aa
3.     aa
4.     AA
Question 26

Select one answer.
10 points
Nondisjunction in meiosis II results in: ______________________
1.     Two cells missing a chromosome and two cells with an additional chromosome.
2.     One cell missing a chromosome, one cell with missing a chromosome and two healthy cells.
3.     Two cells missing a chromosome and two healthy cells.
4.     Two cells with an additional chromosome and two healthy cells

Question27
Select one answer.
10 points
In humans, the condition for normal blood clotting (H) is dominant to hemophilia (h). A male who has normal blood clotting mates with a woman who is a carrier. If they have a son, what is the probability that he will have this condition?
1.     0%
2.     75%
3.     100%
4.     50%
Question 28
Select one answer.
10 points
In humans females are
1.     XY
2.     XX
3.     YY
4.     none of these
Question 29

Select one answer.
10 points
In humans, the condition for normal blood clotting (H) is dominant to hemophilia (h). A male who has normal blood clotting mates with a woman who is a carrier. If they have a daugher, what is the probability that she will have this condition?
1.     75%
2.     50%
3.     100%
4.     0%
Question 30

Select one answer.
10 points
A single visible trait that results from more than one gene is called:
1.     genotypic
2.     phenotypic
3.     pleiotropic
4.     polygenic
Question 31

Select one answer.
10 points
An individual that expresses the recessive trait of a dominant/recessive gene
1.     must be homozygous
2.     must be heterozygous
3.     can be either homozygous or heterozygous
Question 32

Select one answer.
10 points
In humans tongue rolling (T) is dominant to non-rolling (t). Two heterozygous individuals have a child. What is the probability that their child will be able to roll its tongue?
1.     0%
2.     50%
3.     75%
4.     100%
Question 33

Select one answer.
10 points
Use the following information to answer the following four questions.
In dogs, colored fur (E) is dominant to un-colored fur (e). Black fur color (B) is dominant to brown fur color (b). The E gene is epistatic to the B gene. A yellow male dog is mated to a black female. The male’s parents were both brown dogs. The female’s mother was yellow, and her father was brown.
Q1 of 4: What is the genotype of the male dog in this example?
1.     eebb
2.     ee
3.     eeBb
4.     eeBB
Question 34

Select one answer.
10 points
Q2 of 4: What is the genotype of the female dog in this example?
1.     EEBB
2.     EEBb
3.     EeBB
4.     EeBb
Question 35

Select one answer.
10 points
Q3 of 4: What percentage of their puppies will be yellow?
1.     100%
2.     75%
3.     50%
4.     25%
Question 36

Select one answer.
10 points
Q4 of 4: What percentage of the puppies will be homozygous for the B gene?
1.     100%
2.     75%
3.     50%
4.     25%
Question 37

Select one answer.
10 points
This individual studied peas and is often considered the father of genetics.
1.     Carl Sagan
2.     Gregor Mendel
3.     James Watson
4.     Charles Darwin
Question 38

Select one answer.
10 points
Huntington’s disease is an autosomal dominant disorder. A person with the disorder and a person without the disorder mate. Both of these individuals are homozygous. What is the chance that the offspring will develop Huntington’s?
1.     100%
2.     75%
3.     50%
4.     25%
Question 39

Select one answer.
10 points
Sex-linked disorders
1.     are always dominant
2.     are always recessive
3.     can be either dominant or recessive
4.     are neither dominant nor recessive
Question 40

Select one answer.
10 points
Hydrangeas are blue in acidic soil with available aluminum, and they are pink in alkaline soil without available aluminum, but they cannot be orange under any soil condition. The color of hydrangeas is affect by
1.     genetics only
2.     the environment only
3.     genetics and the environment
Question 41

Select one answer.
10 points
A haploid organism has how many copies of each chromosome?
1.     1
2.     2
3.     3
4.     4
Question 42

Select one answer.
10 points
How many copies of each gene does a diploid organism have?
1.     1
2.     2
3.     3
4.     4
Question 43

Select one answer.
10 points
Red (R) flower color is incompletely dominant to white (r) flower color. Which cross will produce 100% pink flowers?
1.     Pink x Pink
2.     Red x White
3.     White x White
4.     Red x Red
Question 44

Select one answer.
10 points
Genotypes provide information about: ______________.
1.     Proteins
2.     DNA
3.     Lipids
4.     Carbohydrates

 
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Dilution Package Series

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Name: _________________ Section:___________

Please complete the following problems by filling in the missing boxes. Don’t forget units where needed.

2.

3.

4.

.

5. Complete the diagram to show how you would make a pond water dilution of 1:100,000

6.

7. Calculate the amount of CFU/ml in the original sample: (your answer should be in scientific notation and include units)

8.Calculate the amount of CFU/ml in the original sample: (your answer should be in scientific notation and include units)

9A. You have counted an average of 4 CFU from having counted 3 large squares using the Quebec colony counter. What is the amount of CFU on this plate?

9B. The dilution factor of the plate in question 9A was 1:56,000. What is the amount of CFU/ml in the original sample?

 
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Current issues in human health and medicine

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Overview

The final project for this course is the creation of a paper. You will choose a health condition or lifestyle habit and identify the ways in which it can affect the systems covered in the course. The final product represents an authentic demonstration of competency because you must show you understand how different body systems work among and between one another to create general health conditions. The project is divided into three milestones, which will be submitted at various points throughout the course to scaffold learning and ensure quality final submissions. These milestones will be submitted in Modules Three, Five, and Seven.

 

Objectives

To successfully complete this project, you will be expected to apply what you have learned in this course and should include several of the following course outcomes:

1. Make informed, intelligent decisions about your health and well-being

2. Discuss the highly connected pathways of all systems of the body

3. Critically analyze current issues in human health and medicine

 

Main Elements

You must address the outcomes in these ways:

 

1. Make informed and intelligent decisions about your health and well-being: Choose a health condition or lifestyle habit and research the ways in which it adversely affects the various systems of the body. You can choose obesity, cigarette smoking, or alcoholism. Or, feel free to select a different topic altogether. Be as detailed as possible when describing the effects it has on the body’s systems. What is happening at the cell and/or tissue level?

 

2. Discuss the connected pathways of the body’s systems: The body’s systems are interrelated in structure and function. Describe the specific relationships they have with one another as you explain why several systems can be affected by one condition or lifestyle habit.

3. Analyze current issues – Finally, find out what is being done to decrease the prevalence of this problem. Has there been any recent legislation implemented? Have any programs been established? Are there any promising research studies taking place?

Format

Milestone One: Outline

In 3-1 Project: Submit Outline of Final Project, you will submit an outline of your final project paper. The format should be an outline with main points and subheads, with enough information to show you have researched and are prepared to begin writing this comprehensive paper. The outline should be 1-2 pages long.

 

Milestone Two: Rough Draft

In 5-1 Project: Submit Rough Draft for Final Project, you will submit a rough draft of your final project paper. The final paper should be 4-6 pages in length, and it must include a cover sheet. Use at least 3 references and cite them, both in-text and at the end of your paper, using APA format.

 

Milestone Three: Final Paper

 
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