Name ___________________ Date ___________ Period _________ # ______
Genetics Web Lab: Mendel’s Pea Plant Experiments
http://www2.edc.org/weblabs/WebLabDirectory1.html
Introduction
1.
Mendel chose pea plants (Pisum satvum) because they possess four important
qualities. These qualities are:
1. All offspring will have the same 7 characteristics generation after generation.
2. Peas have contrasting traits. (eg. purple vs. white flowers)
3. Peas usually reproduce by _____________ pollination because of its anatomy.
4. Pea plants grow quickly and do not require much space.
Plant & Cross
2.
The seven contrasting traits that Mendel observed in Pisum sativum are:
1.
Pea shape (R) - round or wrinkled
2.
Pea color (Y) – yellow or green
3.
Pod shape (I) – inflated or constricted
4.
Pod color (G) – green or yellow
5.
Flower color (P) - purple or white
6.
Plant size (T) – tall or dwarf
7.
Position of flowers (A) – axial or terminal
Predict (Perform the 5 crosses and follow the directions afterward before answering
any of these questions.)
3.
What type(s) of offspring were produced when a plant with round peas was
crossed with itself (self pollination)?
4.
What type(s) of offspring were produced when a plant with wrinkled peas was
crossed with itself (self pollination)?
5.
Explain why one of the crosses resulted in more than one type of pea formed (#3)
while the other resulted in only one type of pea formed (#4).
6.
When you crossed the two wrinkled offspring, what type(s) of seeds did the next
generation (F2) have? Why?
7.
The traits that appear to mask or hide other traits are called _________________.
8.
The traits that seem to be hidden are called _____________________.
Pedigree
9.
What type(s) of offspring are produced when you cross a white flower with itself
(self pollination) or with another white flower (cross pollination)?
Name ___________________ Date ___________ Period _________ # ______
10.
What type(s) of offspring are produced when you cross a purple flower with
itself (self pollination) or with another purple flower (cross pollination)?
Explore
11.
Fill in the following chart as you cross the other contrasting traits that Mendel
collected data on.
Genetic Characteristic
Dominant Trait
Recessive Trait
Pea Shape
Pea Color
Pod Shape
Pod Color
Flower Color
Plant Size
Flower Position
Allele- one letter of an organisms gene that is inherited by one of its parents (one-half of
their genotype)
Axial- flowers located near the middle of the plant
Dominant- traits that appear to mask (or hide) other traits.
Genotype- the entire genetic makeup of an organism
Pedigree- A diagram of a family history used for tracing a trait through several
generations
Phenotype- the outward appearance of an organism that results from the organism’s
genotype
Recessive- traits that can be hidden in one generation and then appear in the next.
Terminal Flowers- located at the ends of the stems
Trait-a distinguishing characteristic