.0/msohtmlclip1/01/clip_image002.gif” alt=”Text box: lab bench used “>Introdu

.0/msohtmlclip1/01/clip_image002.gif” alt=”Text box:
lab bench used
“>Introduction to Genetics
Introduce yourself to the
virtual Genetics lab room to discover how pea plants display Mendelian
inheritance patterns.

Gregor Mendel’s meticulous work with pea
plants allowed him to discover patterns of inheritance in sexually reproducing
organisms. In this introductory virtual lab activity, you can simulate some of
Mendels crosses and data analyses.
Enter the Virtual Bio Lab and
select the title of this lab activity from the Heredity menu on the
whiteboard. You will be taken to the virtual Genetics lab room.
Part A: The Virtual Genetics Lab Room
The virtual Genetics lab room lets you perform
virtual crosses between males and females of a variety of model species to
determine how different traits are inherited. By default, the pea plant lab
environment will appear. In some activities you may be working with human
traits, in which case the settings will look like a physicians office. When
working with other animal species, the lab will again look different.

First
Generation
Select Pea Plant from the Species
Selector. In the box on the lower left part of your screen labeled Experiment
Setup, select Seed Shape as the trait to explore.
The
Genetics lab lets you set each parents genotype for the selected trait and
then perform an unlimited number of crosses to determine how a particular trait
is passed on to the next generation. The simulation limits the number of
offspring per cross to a realistic number for the species in question, however.
In the lower left corner of the Experiment Setup box, set Number of Offspring
to 10.
Now,
set one parental pea plants genotype as homozygous for Wrinkled and the
others genotype as heterozygous. To set a genotype, pull down on each of the
dropdown menus below a given parent.
Next,
click the Cross button. The results of your crosses will be displayed in the
Results boxes to the right of the experiment setup screen. Under the headings
Parents and F1 Offspring, you will see the individuals listed
using names such as MF1, MF2, and so on. (MF1 means male-female number 1the first offspring, which has both
male and female reproductive organs.) To check the phenotypes of an individual
offspring, roll over any of the offspring names. In the window that appears,
the phenotype of the offspring is shown in the first of three boxes and
described to the left. The phenotypes of the parents are shown in the other two
boxes.

.0/msohtmlclip1/01/clip_image004.jpg”>

In the By Generation results panel,
you will find the proportional breakdown of the phenotypes displayed by the
first (F1) generation of ten offspring. The values given at the far
right side of the horizontal bar graphs (Round and Wrinkled) tell you what
proportions of that generation have a particular phenotype. For example, if
0.70 of offspring are wrinkled, that means 70% are wrinkled.

1. In data table below, write the proportions of
the two phenotypes as displayed by the first ten offspring. Then, click the
Cross button again, to simulate the production of 10 more offspring. Record
the new phenotype proportions (for 20 offspring) in the next row. Repeat this
process until the parents have produced 100 offspring.

Results
of Cross

When
F1 generation
consists
of

Proportion
with round seed phenotype is

Proportion
with wrinkled seed phenotype is

10 offspring

20 offspring

30 offspring

40 offspring

50 offspring

60 offspring

70 offspring

80 offspring

90 offspring

100 offspring

2. What happened
to the proportions of the two phenotypes as the F1 generation grew
from 10 to 100 offspring? Why?
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________

3. If Mendel had
only looked at a single cross that produced ten offspring to determine the
pattern of inheritance of seed shape in pea plants, what might he have
inferred?
___________________________________________________________
___________________________________________________________
___________________________________________________________

4. How can two parents with only one round
allele between themonly 1 out of 4 allelesproduce an F1 generation
in which 50% of individuals have round seeds?
___________________________________________________________
___________________________________________________________
_________________________________________________________________
Next
Generation
In the lower
middle of the Experiment Setup box, click Next Generation. Select Manual
Crosses. You will now be able to choose parents for the next generation (F2)
in the dropdown menus under Parent 1 and Parent 2. You can choose which F1
offspring to use as parents by rolling over the list of the F1
offspring in the Results box in the middle of the screen. Note which F1
offspring are wrinkled, then choose two of those names from the menus under
Parent 1 and Parent 2 to pair them up them for mating.

5. Click the Cross
button a few times to produce the F2 generation. What are the
results? Do the results support the idea that pea plant seed shape has a
dominant/recessive pattern of inheritance? Explain your reasoning.
___________________________________________________________
___________________________________________________________
______________________________________________________________________________________________________________________
___________________________________________________________
Part B: Pod Shape
Click the Reset button in the lower
right corner of the Experiment Setup box. Keeping pea plants as the subject,
select Pod Shape as the trait you will investigate next. Cross a parent that
is homozygous for Constricted pod shape with a heterozygote. Once again,
repeat the cross until the parent plants have produced 100 offspring.

6. Look at the results of your crosses. Does
it appear that pod shape is a dominant/recessive trait? If so, which allele is
dominant, and which is recessive?
___________________________________________________________
______________________________________________________________________________________________________________________
___________________________________________________________
___________________________________________________________
7. If
you were a pea farmer and you had to produce both the constricted and the
inflated varieties of peas to satisfy the market, how would you go about
ensuring that your plants would produce adequate amounts of both types? (Hint:Think about what would happen if
pea plants were allowed to cross-pollinate.)
___________________________________________________________
___________________________________________________________
______________________________________________________________________________________________________________________
___________________________________________________________
___________________________________________________________

Part C: Flower Position
Reset the experiment setup but keep the
pea plant as the model organism. This time, select flower position as the trait
to investigate. Once again, you will determine the pattern of inheritance for
this trait. This time, however, you will choose which parental genotypes to
cross and how to use the results to determine the pattern of inheritance.

8. Use the space below to record
the procedure and results of your experiment.
___________________________________________________________
_________________________________________________________________________________________________________________________________________________________________________________
___________________________________________________________
___________________________________________________________
9. How many offspring did you produce in each cross before you felt
confident enough to infer the pattern of inheritance based on your results?
Explain your reasoning.
___________________________________________________________
_________________________________________________________________________________________________________________________________________________________________________________
___________________________________________________________
___________________________________________________________

.0/msohtmlclip1/01/clip_image002.gif” alt=”Text box:
lab bench used
“>Introduction to GeneticsIntroduce yourself to the
virtual Genetics lab room to discover how pea plants display Mendelian
inheritance patterns. Gregor Mendel’s meticulous work with pea
plants allowed him to discover patterns of inheritance in sexually reproducing
organisms. In this introductory virtual lab activity, you can simulate some of
Mendels crosses and data analyses.Enter the Virtual Bio Lab and
select the title of this lab activity from the Heredity menu on the
whiteboard. You will be taken to the virtual Genetics lab room.Part A: The Virtual Genetics Lab RoomThe virtual Genetics lab room lets you perform
virtual crosses between males and females of a variety of model species to
determine how different traits are inherited. By default, the pea plant lab
environment will appear. In some activities you may be working with human
traits, in which case the settings will look like a physicians office. When
working with other animal species, the lab will again look different.First
GenerationSelect Pea Plant from the Species
Selector. In the box on the lower left part of your screen labeled Experiment
Setup, select Seed Shape as the trait to explore. The
Genetics lab lets you set each parents genotype for the selected trait and
then perform an unlimited number of crosses to determine how a particular trait
is passed on to the next generation. The simulation limits the number of
offspring per cross to a realistic number for the species in question, however.
In the lower left corner of the Experiment Setup box, set Number of Offspring
to 10. Now,
set one parental pea plants genotype as homozygous for Wrinkled and the
others genotype as heterozygous. To set a genotype, pull down on each of the
dropdown menus below a given parent. Next,
click the Cross button. The results of your crosses will be displayed in the
Results boxes to the right of the experiment setup screen. Under the headings
Parents and F1 Offspring, you will see the individuals listed
using names such as MF1, MF2, and so on. (MF1 means male-female number 1the first offspring, which has both
male and female reproductive organs.) To check the phenotypes of an individual
offspring, roll over any of the offspring names. In the window that appears,
the phenotype of the offspring is shown in the first of three boxes and
described to the left. The phenotypes of the parents are shown in the other two
boxes. .0/msohtmlclip1/01/clip_image004.jpg”>In the By Generation results panel,
you will find the proportional breakdown of the phenotypes displayed by the
first (F1) generation of ten offspring. The values given at the far
right side of the horizontal bar graphs (Round and Wrinkled) tell you what
proportions of that generation have a particular phenotype. For example, if
0.70 of offspring are wrinkled, that means 70% are wrinkled.1. In data table below, write the proportions of
the two phenotypes as displayed by the first ten offspring. Then, click the
Cross button again, to simulate the production of 10 more offspring. Record
the new phenotype proportions (for 20 offspring) in the next row. Repeat this
process until the parents have produced 100 offspring.Results
of CrossWhen
F1 generation consists
ofProportion
with round seed phenotype isProportion
with wrinkled seed phenotype is10 offspring20 offspring30 offspring40 offspring50 offspring60 offspring70 offspring80 offspring90 offspring100 offspring2. What happened
to the proportions of the two phenotypes as the F1 generation grew
from 10 to 100 offspring? Why? ___________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ 3. If Mendel had
only looked at a single cross that produced ten offspring to determine the
pattern of inheritance of seed shape in pea plants, what might he have
inferred?___________________________________________________________ ______________________________________________________________________________________________________________________ 4. How can two parents with only one round
allele between themonly 1 out of 4 allelesproduce an F1 generation
in which 50% of individuals have round seeds?___________________________________________________________ ____________________________________________________________________________________________________________________________ Next
Generation In the lower
middle of the Experiment Setup box, click Next Generation. Select Manual
Crosses. You will now be able to choose parents for the next generation (F2)
in the dropdown menus under Parent 1 and Parent 2. You can choose which F1
offspring to use as parents by rolling over the list of the F1
offspring in the Results box in the middle of the screen. Note which F1
offspring are wrinkled, then choose two of those names from the menus under
Parent 1 and Parent 2 to pair them up them for mating. 5. Click the Cross
button a few times to produce the F2 generation. What are the
results? Do the results support the idea that pea plant seed shape has a
dominant/recessive pattern of inheritance? Explain your reasoning.___________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Part B: Pod ShapeClick the Reset button in the lower
right corner of the Experiment Setup box. Keeping pea plants as the subject,
select Pod Shape as the trait you will investigate next. Cross a parent that
is homozygous for Constricted pod shape with a heterozygote. Once again,
repeat the cross until the parent plants have produced 100 offspring.6. Look at the results of your crosses. Does
it appear that pod shape is a dominant/recessive trait? If so, which allele is
dominant, and which is recessive? ___________________________________________________________ ______________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________7. If
you were a pea farmer and you had to produce both the constricted and the
inflated varieties of peas to satisfy the market, how would you go about
ensuring that your plants would produce adequate amounts of both types? (Hint:Think about what would happen if
pea plants were allowed to cross-pollinate.) ___________________________________________________________ _________________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ Part C: Flower PositionReset the experiment setup but keep the
pea plant as the model organism. This time, select flower position as the trait
to investigate. Once again, you will determine the pattern of inheritance for
this trait. This time, however, you will choose which parental genotypes to
cross and how to use the results to determine the pattern of inheritance. 8. Use the space below to record
the procedure and results of your experiment.___________________________________________________________ _________________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________ 9. How many offspring did you produce in each cross before you felt
confident enough to infer the pattern of inheritance based on your results?
Explain your reasoning.___________________________________________________________ _________________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________________________________________