Classic Mendelian genetics using fruit fly crosses and a Punnett Square.

Classic Mendelian genetics using fruit fly crosses and a Punnett Square.

This assignment should help assess your knowledge and understanding of Chapter 10 concepts involving classic Mendelian genetics using fruit fly crosses and a Punnett Square.

Directions

Please complete the Virtual Laboratory Activity: Punnett Square, found here http://www.mhhe.com/biosci/genbio/virtual_labs_2K8/pages/PunnettSquares.html
Be sure to read the "Instructions" document before beginning the lab exercise.
Complete the lab exercise portion by clicking on the "Laboratory Exercise" link.
Complete parts I and II of the "Post Lab Quiz and Lab Report" by clicking on the appropriate link. For your convenience, here is the worksheet, PunnettSquaresWorksheet.doc.
Save this document as "Unit 3 Virtual Lab Report_Your Last Namt" in .rtf, .doc, or .docx format.
Complete the worksheet and submit it as an attachment using the link above, Unit 3 Virtual Laboratory.
Grading

Required, 30 points. 


Virtual Lab: Punnett Squares
Worksheet

Part I: Answer the following questions:
1. Which of the following is most inclusive?
a. allele
b. genotype

2. Dominant alleles are represented by:
a. an upper case letter
b. a lower case letter
c. it does not matter what type of letter is used

3. In fruit flies, gray body color is dominant over black body color. Using the
letter G to represent body color, what is the genotype of a heterozygous gray
bodied
fly?
a. GG
b. gg
c. Gg
d. GGgg

4. All of the offspring of two gray bodied flys are also gray. What can you
conclude about the genotypes of the parent flies?
a. They are both heterozygous
b. They are both homozygous dominant

c. They are both homozygous recessive
d. You cannot conclude anything definitively about the parental
genotypes

5. Some of the offspring of two gray bodied flies are black. What can you
conclude about the genotypes of the parent flies?
a. They are both heterozygous
b. They are both homozygous dominant
c. They are both homozygous recessive
d. You cannot conclude anything definitively about the parental
genotypes

Part II: Follow the instructions in the Question column to complete the virtual lab
scenarios and record your data:
Complete all ten scenarios and record your results in Table 1.
When you record a ratio, whether it is genotypic or phenotypic ratio, always record the
most dominant characteristic first, followed by the recessive. For example, when
recording genotypic ratios:
1) If your offspring genotypes include 1 GG, 2 Gg, and 1 gg, the ratio would be:
1
GG : 2 Gg : 1 gg
2) If your offspring genotypes include 2 GG and 2 Gg, the ratio would be:
2
GG : 2 gg (or 1:1 in the reduced form)
3) If your offspring genotypes are 4 gg, then the ratio would be written as::
4
gg
When you record phenotypic ratios for a monohybrid cross, there are only two possible
phenotypes - either the dominant phenotype or the recessive phenotype. So you do not
need to indicate the phenotype, simply put the dominant # first, followed by the recessive
#:
4) If your offspring phenotypes are 3 dominant and 1 recessive, the ratio is:
3:1
5) If your offspring phenotypes are 4 dominant and 0 recessive, the ratio is:
4:0
6) If your offspring phenotypes are 0 dominant and 4 recessive, the ratio is:
0:4

Table 1:
Scenario #
1
2
3
4
5
6
7
8
9
10

Genotype of
Parent I

Genotype of
Parent II

Genotypic Ratio
of Offspring

Phenotypic Ratio
of Offspring