Category: 1st Semester

Genetics Worksheet Bi Chapter 9

 Fundamentals of Genetics

Section 9-1 Mendel’s Legacy

1. What scientist is responsible for our study of heredity?

2. Define heredity.

3. What plant did Mendel use for his hereditary experiments?

4. Name the 7 characteristics, giving both dominant and recessive forms of the pea plants, in Mendel’s experiments.

5. In order to study pea plant traits, Mendel had to control __________________ among the plants.

6. Define pollination & name 2 types.

7. How do pea plants normally pollinate?

8. How can cross-pollination of pea plants be done?

9. How did Mendel obtain pure pea plants?

10. What is the P1 generation? How is it obtained?

11. What is the F1 generation &how is it obtained?

12. How did Mendel obtain his F2 generation?

13. When Mendel crossed his P1 plants to get the F1 generation, what ratio did he get?

14. What is the difference between dominant & recessive genes?

15. State Mendel’s law of segregation.

16. What are alleles?

Section 9-2 Genetic Crosses

17 What is the difference between genotypes & phenotypes?

18. Write the 2 genotypes for a purple flower.

19. Write the genotype for a white flower.

20. What is the difference in a homozygous and a heterozygous genotype?

21. What is  probability & tell 3 ways they can be expressed.

22. What is the probability that you will get “heads” each time you flip a coin?

23. What is a monohybrid cross?

24. Give an example of a monohybrid cross.

25. What is a Punnett Square used for?

26. Sketch the Punnett Square for crossing a pure purple flower with a white flower.

27. Use a Punnett Square to solve this cross — PP x pp.

28. What percentage of the offspring from this cross are purple? White?

29. Use a Punnett Square to solve this cross in guinea pigs — BB x Bb. Hint: See page 174.

30. In the above cross, what coat colors & percents did you get?

31. What phenotype (coat color) would each of these guinea pig genotypes result in:

        a. Bb?

        b. BB?

        c. bb?

32. Use a Punnett Square to solve this cross for coat color in rabbits: Bb x Bb?

33. What percent of the rabbits will have black fur? Brown fur? What ratio does this give for coat color?

34. Define genotypic ratio.

35. What is the genotypic ratio for all F1 crosses (bb x Bb)?

36. Define phenotypic ratio.

37. What is the phenotypic ratio for all F1 crosses?

38. What is a testcross?

39. A testcross can determine which individual’s phenotype is ________________________.

40. Use a Punnett Square to solve the following 2 testcrosses:

        a. BB x Bb

        b. bb x Bb

41. In each of the above testcrosses, tell how many offspring have black coats (dominant) and how many will have brown (recessive) coats?

42. What does complete dominance mean?

43. Give an example of complete dominance in pea plants.

44. What is incomplete dominance?

45. How many alleles influence the phenotype in:

        a. complete dominance?

        b. incomplete dominance?

46. Using four-o-clocks, give an example of how incomplete dominance occurs. Be sure to tell all possible genotypes & phenotypes.

47. Give the following ratios for crossing 2 pink four-o-clocks (Rr x Rr):

        a. Genotypic ratio?

        b. Phenotypic ratio?

48. Define codominance.

49. In what genotype does codominance appear?

50. In horses, _________________ coat color is a result of codominance.

51. Write the genotype for roan coat color & tell the color of each allele in the genotype.

52. What is a dihybrid cross?

53. How many different genotypes will result in a dihybrid cross when 2 homozygous organisms are crossed?

54. The offspring from a dihybrid cross of 2 homozygous organisms will all be __________________________.

55. Use a Punnett Square to show the results of the following cross: RrYy x RrYy

56. How many different genotypes resulted from this cross?

57. How many different phenotypes resulted from this cross?

58. Write the genotypes for each of these phenotypes:

        a. Round, green seeds

        b. Wrinkled, yellow seeds

        c. Wrinkled, green seeds

Graphing Practice

Graphing Practice

Introduction

  • Graphing is an important procedure used by scientists to display the data that is collected during a controlled experiment
  • Line graphs must be constructed correctly to accurately portray the data collected
  • Many times the wrong construction of a graph detracts from the acceptance of an individual’s hypothesis
  • A graph contains five major parts:
    a. Title
    b. The independent variable
    c. The dependent variable
    d. The scales for each variable
    e. A legend
  • The title: depicts what the graph is about. By reading the title, the reader should get an idea about the graph. It should be a concise statement placed above the graph.
  • The Independent Variable: is the variable that can be controlled by the experimenter. It usually includes time (dates, minutes, hours), depth (feet, meters), temperature (Celsius). This variable is placed on the X axis (horizontal axis).
  • The Dependent Variable: is the variable that is directly affected by the independent variable. It is the result of what happens because of the independent variable. Example: How many oxygen bubbles are produced by a plant located five meters below the surface of the water? The oxygen bubbles are dependent on the depth of the water. This variable is placed on the Y-axis or vertical axis.
  • The Scales for each Variable: In constructing a graph one needs to know where to plot the points representing the data. In order to do this a scale must be employed to include all the data points. This must also take up a conservative amount of space. It is not suggested to have a run on scale making the graph too hard to manage. The scales should start with 0 and climb based on intervals such as: multiples of 2, 5, 10, 20, 25, 50, or 100. The scale of numbers will be dictated by your data values.
  • The Legend: is a short descriptive narrative concerning the graph’s data. It should be short and concise and placed under the graph.
  • The Mean for a group of variables: To determine the mean for a group of variables, divide the sum of the variables by the total number of variables to get an average.
  • The median for a group of variables: To determine median or “middle” for an even number of values, put the values in ascending order and take the average of the two middle values.    e.g.    2, 3, 4, 5, 9, 10     Add 4+5 (2 middle values) and divide by 2 to get 4.5
  • The mode for a group of variables: The mode for a group of values is the number that occurs most frequently.     e.g.   2, 5,  8, 2,  6,  11    The number 2 is the mode because it occurred most often (twice)  

Procedure 1:
Using the following data, answer the questions below and then construct a line graph.

 

Depth in meters Number of Bubbles / minute Plant A Number of Bubbles / minute Plant B
2 29 21
5 36 27
10 45 40
16 32 50
25 20 34
30 10 20

 

 

1. What is the dependent variable and why?  

2. What is the independent variable and why?

3. What title would you give the graph? .

4. What are the mean, median, and mode of all 3 columns of data? 

a). Depth :                      Mean____________Median__________Mode________ 

b). Bubble Plant A.:        Mean ____________Median_________Mode________ 

c). Bubbles Plant B:        Mean ____________Median_________Mode________

Graph Title: _________________________________________________________

Legend: ______________________________________________________________ 

Procedure 2:
Diabetes is a disease affecting the insulin producing glands of the pancreas. If there is not enough insulin being produced by these cells, the amount of glucose in the blood will remain high. A blood glucose level above 140 for an extended period of time is not considered normal. This disease, if not brought under control, can lead to severe complications and even death. 

Answer the following questions concerning the data below and then graph it.  

 

Time After Eating hours Glucose mg /dL of Blood Person A Glucose mg /dL of Blood Person B
0.5 170 180
1 155 195
1.5 140 230
2 135 245
2.5 140 235
3 135 225
4 130 200

 

 1. What is the dependent variable and why?

2. What is the independent variable and why?

3. What title would you give the graph?

4. Which, if any, of the above individuals (A or B) has diabetes? 

5. What data do you have to support your hypothesis? 

6. If the time period were extended to 6 hours, what would the expected blood glucose level for Person B? 

Title: ________________________________________________________________

Legend: ______________________________________________________________

Summary:
1. What conclusions can be determined from the data in graph 1?

2. What conclusions can be determined from the data in graph 2?

3. Can the data in each of these graphs be used to construct other types of graphs?

4. If so, what other graph types can be constructed?

 
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