Perfect Solution: UMUC Biology 102 103 Lab 5: Meiosis.

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UMUC Biology 102/103

Lab 5: Meiosis

INSTRUCTIONS:

 

·         On your own and without assistance, complete this Lab 5Answer Sheet electronically and submit it via the Assignments Folder by the date listed intheCourse Schedule (underSyllabus).

·         To conduct your laboratory exercises, use the Laboratory Manual located under Course Content. Read the introduction and the directions for each exercise/experiment carefully before completing the exercises/experiments and answering the questions.

·         Save your Lab 5Answer Sheet in the following format:  LastName_Lab5 (e.g., Smith_Lab5).

·         You should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf) file for best compatibility.

 

Pre-Lab Questions

 

1. Compare and contrast mitosis and meiosis.

 

 

1.  What major event occurs during interphase?

 

 

Experiment 1: Following Chromosomal DNA Movement through Meiosis

In this experiment, you will model the movement of the chromosomes through meiosis I and II to create gametes.

Materials 2 Sets of Different Colored Pop-it® Beads (32 of each – these may be any color) 8 5-Holed Pop-it® Beads (used as centromeres)

 

Procedure:

Part 1: Modeling Meiosis without Crossing Over

As prophase I begins, the replicated chromosomes coil and condense…

1. Build a pair of replicated, homologous chromosomes. 10 beads should be used to create each individual sister chromatid (20 beads per chromosome pair). Two five-holed beads represent each centromere. To do this…

Figure 3: Bead set-up. The blue beads represent one pair of sister chromatids and the black beads represent a second pair of sister chromatids. The black and blue pair are homologous.

1. 1. Start with 20 beads of the same color to create your first sister chromatid pair. Five beads must be snapped together for each of the four different strands. Two strands create the first chromatid, and two strands create the second chromatid with a 5-holed bead at the center of each chromatid.  This creates an “I” shape.
   2. Connect the “I” shaped sister chromatids by the 5-holed beads to create  an “X” shape.
   3. Repeat this process using 20 new beads (of a different color) to create the second sister chromatid pair.
2. Assemble a second pair of replicated sister chromatids; this time using 12 beads, instead of 20, per pair (six beads per each complete sister chromatid strand).
3. Pair up the homologous chromosome pairs created in Step 1 and 2. DO NOT SIMULATE CROSSING OVER IN THIS TRIAL. You will simulate crossing over in Part 2.
4. Configure the chromosomes as they would appear in each of the stages of meiotic division (prophase I and II, metaphase I and II, anaphase I and II, telophase I and II, and cytokinesis).
5. Diagram the corresponding images for each stage in the sections titled “Trial 1 – Meiotic Division Beads Diagram”. Be sure to indicate the number of chromosomes present in each phase.

Figure 4: Second set of replicated chromosomes.

1. Disassemble the beads used in Part 1. You will need to recycle these beads for a second meiosis trial in Steps 8 – 13.

Part 1 – Meiotic Division Beads Diagram

Prophase I

 

Metaphase I

 

Anaphase I

 

Telophase I

 

Prophase II

 

Metaphase II

Anaphase II

 

Telophase II

 

Cytokinesis

Part 2: Modeling Meiosis with Crossing Over

1. Build a pair of replicated, homologous chromosomes. 10 beads should be used to create each individual sister chromatid (20 beads per chromosome pair). Two five-holed beads represent each centromere. To do this…
   1. a. Start with 20 beads of the same color to create your first sister chromatid pair. Five beads must be snapped together for each of the four different strands. Two strands create the first chromatid, and two strands create the second chromatid with a 5-holed bead at the center of each chromatid.  This creates an “I” shape.
   2. Connect the “I” shaped sister chromatids by the 5-holed beads to create  an “X” shape.
   3. Repeat this process using 20 new beads (of a different color) to create the second sister chromatid pair.
2. Assemble a second pair of replicated sister chromatids; this time using 12 beads, instead of 20, per pair (six beads per each complete sister chromatid strand). Snap each of the four pieces into a new five-holed bead to complete the set up.
3. Pair up the homologous chromosomes created in Step 8 and 9.
4. SIMULATE CROSSING OVER. To do this, bring the two homologous pairs of sister chromatids together (creating the chiasma) and exchange an equal number of beads between the two. This will result in chromatids of the same original length, there will now be new combinations of chromatid colors.
5. Configure the chromosomes as they would appear in each of the stages of meiotic division (prophase I and II, metaphase I and II, anaphase I and II, telophase I and II, and cytokinesis).
6. Diagram the corresponding images for each stage in the section titled “Trial 2 – Meiotic Division Beads Diagram”. Be sure to indicate the number of chromosomes present in each cell for each phase. Also, indicate how the crossing over affected the genetic content in the gametes from Part1 versus Part 2.

Part 2 –  Meiotic Division Beads Diagram:

Prophase I

 

Metaphase I

 

Anaphase I

 

Telophase I

 

Prophase II

 

Metaphase II

 

Anaphase II

 

Telophase II

 

Cytokinesis

 

 

Post-Lab Questions

1.      What is the ploidy of the DNA at the end of meiosis I? What about at the end of meiosis II?

 

2.      How are meiosis I and meiosis II different?

 

3.      Why do you use non-sister chromatids to demonstrate crossing over?

 

4.      What combinations of alleles could result from a crossover between BD and bd chromosomes?

 

 

 

5.      How many chromosomes were present when meiosis I started?

 

6.      How many nuclei are present at the end of meiosis II? How many chromosomes are in each?

 

7.      Identify two ways that meiosis contributes to genetic recombination.

 

8.      Why is it necessary to reduce the number of chromosomes in gametes, but not in other cells?

 

9.      Blue whales have 44 chromosomes in every cell. Determine how many chromosomes you would expect to find in the following:

 

Sperm Cell:

Egg Cell:

Daughter Cell from Mitosis:

Daughter Cell from Meiosis II:

 

10.  Research and find a disease that is caused by chromosomal mutations. When does the mutation occur? What chromosomes are affected? What are the consequences?

 

11.  Diagram what would happen if sexual reproduction took place for four generations using diploid (2n) cells.

 

 

Experiment 2: The Importance of Cell Cycle Control

Some environmental factors can cause genetic mutations which result in a lack of proper cell cycle control (mitosis). When this happens, the possibility for uncontrolled cell growth occurs. In some instances, uncontrolled growth can lead to tumors, which are often associated with cancer, or other biological diseases.

In this experiment, you will review some of the karyotypic differences which can be observed when comparing normal, controlled cell growth and abnormal, uncontrolled cell growth. A karyotype is an image of the complete set of diploid chromosomes in a single cell.

 

 

 

 

Procedure

Materials *Computer Access *Internet Access

*You Must Provide

 

 

1. Begin by constructing a hypothesis to explain what differences you might observe when comparing the karyotypes of human cells which experience normal cell cycle control versus cancerous cells (which experience abnormal, or a lack of, cell cycle control). Record your hypothesis in Post-Lab Question 1.

   Note: Be sure to include what you expect to observe, and why you think you will observe these features. Think about what you know about cancerous cell growth to help construct this information

2. Go online to find some images of abnormal karyotypes, and normal karyotypes. The best results will come from search terms such as “abnormal karyotype”, “HeLa cells”, “normal karyotype”, “abnormal chromosomes”, etc. Be sure to use dependable resources which have been peer-reviewed
3. Identify at least five abnormalities in the abnormal images. Then, list and draw each image in the Data section at the end of this experiment. Do these abnormalities agree with your original hypothesis?

Hint: It may be helpful to count the number of chromosomes, count the number of pairs, compare the sizes of homologous chromosomes, look for any missing or additional genetic markers/flags, etc.

Data

 

 

 

 

 

Post-Lab Questions

1.      Record your hypothesis from Step 1 in the Procedure section here.

 

 

2.      What do your results indicate about cell cycle control?

 

 

3.      Suppose a person developed a mutation in a somatic cell which diminishes the performance of the body’s natural cell cycle control proteins. This mutation resulted in cancer, but was effectively treated with a cocktail of cancer-fighting techniques. Is it possible for this person’s future children to inherit this cancer-causing mutation? Be specific when you explain why or why not.

 

 

4.      Why do cells which lack cell cycle control exhibit karyotypes which look physically different than cells with normal cell cycle.

 

 

5.      What are HeLa cells? Why are HeLa cells appropriate for this experiment?

 

Perfect Solution: UMUC Biology 102 103 Lab 5: Meiosis

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Biology Lab Worksheet. Lab 1 Introduction to Science BIO101

Student Name: Click here to enter text. Kit Code (located on the lid of your lab kit):

Exercise 1: Data Interpretation

Dissolved oxygen is oxygen that is trapped in a fluid, such as water. Since many living organism requires oxygen to survive, it is a necessary component of water systems such as streams, lakes and rivers in order to support aquatic life. The dissolved oxygen is measured in units of ppm (parts per million). Examine the data in Table 4 showing the amount of dissolved oxygen present and the number of fish observed in the body of water the sample was taken from; finally, answer the questions below.

Table 4: Water Quality vs. Fish Population

Dissolved Oxygen (ppm)

0

2

4

6

8

10

12

14

16

18

Number of Fish Observed

0

1

3

10

12

13

15

10

12

13

Post-Lab Questions

1. What patterns do you observe based on the information in Table 4?

Click here to enter text.

2. Develop a hypothesis relating to the amount of dissolved oxygen measured in the water sample and the number of fish observed in the body of water.

Click here to enter text.

3. What would your experimental approach be to test this hypothesis?

Click here to enter text.

4. What would be the independent and dependent variables?

Click here to enter text.

5. What would be your control?

Click here to enter text.

6. What type of graph would be appropriate for this data set? Why?

Click here to enter text.

7. Graph the data from Table 4: Water Quality vs. Fish Population (found at the beginning of this exercise).

Insert graph here:

8. Interpret the data from the graph made in Question 7.

Click here to enter text.

Exercise 2: Testable Observations

Determine which of the following observations are testable. For those that are testable, answer the following:

Determine if the observation is qualitative or quantitative. Write a hypothesis and null hypothesis. What would be your experimental approach? What are the dependent and independent variables? What are your controls – both positive and negative?

Observations

1. A plant grows three inches faster per day when placed on a window sill than it does when placed on a on a coffee table in the middle of the living room.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

2. The teller at the bank with brown hair and brown eyes is taller than the other tellers.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

3. When Sally eats healthy foods and exercises regularly, her blood pressure is 10 points lower than when she does not exercise and eats fatty foods.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

4. The Italian restaurant across the street closes at 9 pm, but the one two blocks away closes at 10 pm.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

5. For the past two days, the clouds have come out at 3 pm, and it has started raining at 3:15 pm.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

6. George did not sleep at all the night following the start of daylight savings.

Testable?- Hypothesis- Null Hypothesis- Experimental Approach- Dependent Variable- Independent Variable- Control(s)-

Exercise 3: Unit Conversions

For each of the following, convert each value into the designated units.

1. 46,756,790 mg = kg

2. 5.6 hours = seconds

3. 13.5 cm = inches

4. 47 °C = °F

Exercise 4: Accuracy and Precision

For the following, determine whether the information is accurate, precise, both or neither.

1. During gym class, four students decided to see if they could beat the norm of 45 sit-ups in a minute. The first student did 64 sit-ups, the second did 69, the third did 65, and the fourth did 67.

2. The average score for the 5th grade math test is 89.5. The top 5th graders took the test and scored 89, 93, 91 and 87.

3. Yesterday the temperature was 89 °F, tomorrow it’s supposed to be 88 °F and the next day it’s supposed to be 90 °F, even though the average for September is only 75 °F degrees!

4. Four friends decided to go out and play horseshoes. They took a picture of their results shown below:

5. A local grocery store was holding a contest to see who could most closely guess the number of pennies that they had inside a large jar. The first six people guessed the numbers 735, 209, 390, 300, 1005 and 689. The grocery clerk said the jar actually contains 568 pennies.

Exercise 5: Significant Digits and Scientific Notation

Part 1: Determine the number of significant digits in each number and write out the specific significant digits.

1. 405000

Number of significant digits- Specific significant digits-

2. 0.0098

Number of significant digits- Specific significant digits-

3. 39.999999

Number of significant digits- Specific significant digits-

4. 13.00

Number of significant digits- Specific significant digits-

5. 80,000,089

Number of significant digits- Specific significant digits-

6. 55,430.00

Number of significant digits- Specific significant digits-

7. 0.000033

Number of significant digits- Specific significant digits-

8. 620.03080

Number of significant digits- Specific significant digits-

Part 2: Write the numbers below in scientific notation, incorporating what you know about significant digits.

1. 70,000,000,000 –

2. 0.000000048 –

3. 67,890,000 –

4. 70,500 –

5. 450,900,800 –

6. 0.009045 –

7. 0.023 –

Exercise 6: Percentage Error

In the questions below, determine the percentage error.

1. A dad holds five coins in his hand. He tells his son that if he can guess the amount of money he is holding within 5% error he can have the money. The son guesses that he is holding 81 cents. The dad opens his hand and displays 90 cents. Did the son guess close enough to receive the money from his father?

2. A science teacher tells her class that their final project requires the students to measure a specific variable and determine the velocity of a car with no more than 2.5% error. Jennifer and Johnny work hard and decide the velocity of the car is 34.87 m/s. The teacher informs them that the actual velocity is 34.15 m/s. Will Jennifer and Johnny pass their final project?

3. A locomotive train is on its way from Chicago, IL to Madison, WI. The trip is said to last 3.15 hours. When the train arrives in Madison the conductor notices it actually took them 3.26 hours. The train company prides itself on always having its trains to the station within a 3% error of the expected time. Will the train company live up to its reputation on this trip?

4. A coach tells his little league players that hitting a 0.275 batting average, within 7% percentage error, means that they had a really great season. Seven year old Tommy ended the season hitting a 0.258 batting average. According to his coach, did he have a great season?

Exercise 7: Experimental Variables

Determine the variables tested in the each of the following experiments. If applicable, determine and identify any positive or negative controls.

1. A study is being done to test the effects of habitat space on the size of fish populations. Different sized aquariums are set up with six goldfish in each one. Over a period of six months, the fish are fed the same type and amount of food. The aquariums are equally maintained and cleaned throughout the experiment. The temperature of the water is kept constant. At the end of the experiment the number of surviving fish are surveyed.

A. Independent Variable:

B. Dependent Variable:

C. Controlled Variables/Constants:

D. Experimental Controls/Control Groups:

2. To determine if the type of agar affects bacterial growth, a scientist cultures E. coli on four different types of agar. Five petri dishes are set up to collect results:

. One with nutrient agar and E. coli

. One with mannitol-salt agar and E. coli

. One with MacConkey agar and E. coli

. One with LB agar and E. coli

. One with nutrient agar but NO E. coli

All of the petri dishes received the same volume of agar, and were the same shape and size. During the experiment, the temperature at which the petri dishes were stored, and at the air quality remained the same. After one week the amount of bacterial growth was measured.

A. Independent Variable:

B. Dependent Variable:

C. Controlled Variables/Constants:

D. Experimental Controls/Control Groups:

Biology Lab Worksheet

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