Lab Report_Genetics.docx - Mendelian Genetics Group Lab...

Mendelian Genetics Group Lab Report
(20 points)
did not have access to F
1
and F
2
seedlings (intl. lab kit)
A. Predictions
1. (1 pt) The P
1
plant was a purple stem, normal height plant (PPSS) and the P
2
plant was a non-purple
stem, dwarf plant (ppss), and both plants were homozygous for these two traits. Draw the cross of the P
and P
2
parental plants. Based on this cross, what is the predicted phenotype of all of the F
1
plants?
1
(Phenotypic ratio, Biology Online)
2. (1 pt) Two F
1
plants were crossed. Taking only stem color into consideration, what phenotypic ratio do
you expect for the F
2
generation seedlings and why?

3. (1 pt) Taking only stem height into consideration, what phenotypic ratio do you expect for the F
2
generation seedlings and why?

recessive allele can only have one genotype (ss - homozygous recessive), and only one phenotype,
appearing dwarf in height. When the two hybrid normal height plants from the F
1
generation are crossed,
there is one homozygous dominant plant, two heterozygous plants, and one homozygous recessive plant
in the F
2
generation. Because the homozygous dominant and heterozygous plants both appear normal
height, there will be three normal height phenotypes. The homozygous recessive plant appears dwarf in
height, so there is dwarf phenotype. This results in a 3:1 phenotypic ratio.
4. (1 pt) Taking both stem color and height into consideration, what phenotypic ratio do you expect,
considering both traits together, for the F
2
generation seedlings. Explain (show your math or a Punnett
Square).