Name: ANSWER KEY
Lesson 60: Mendel, First Geneticist (Pgs. 34-38)
During reading – As you read, “Stop to think” and answer these questions.
Stopping to Think 1- Just discuss with your group.
Stopping to Think 2a.) List the advantages for Mendel using pea plants for his breeding investigation.

Grow into mature plants very quickly.

They produce numerous seeds rapidly.

Many observable characteristics that come in just two alternatives with no blending of
these traits.
b.) Why did Mendel do so many crosses for the same characteristic?
So that he had a very large sample size.
Stopping to Think 3- No answer or discussion needed.
Analysis1. Record Mendel’s results, decide from the data which trait is dominant and which is recessive and
calculate the ratios below.
Ratio
Actual results
Dominant : Recessive
white
705:224
705/224 = 3/1
¾ purple ¼ white
Yellow
Green
6,022: 2,001
3.01:1
3/4 yellow
Seed Surface
Smooth
Wrinkled
Pod Color
Green
Yellow
Dominant
Trait
Recessive
Trait
flower color
purple
Seed color
Characteristic
Dominant : Recessive
Simplified ratio
5,474: 1,850
Fraction
¼ green
2.96: 1
¾ smooth,
¼ wrinkled
428: 152
2.82: 1
¾ green, ¼
yellow
2. Look at the Table and explain how a ratio of 3:1 purple to white offspring is the same as ¾ purple
and ¼ white offspring.
VERY IMPORTANT NOTE: A 3:1 ratio says that for every 1 white offspring there are 3 purple
offspring, so there has to be a total of 4 which makes 1 out of 4 white (1/4) and 3 out of 4
purple.
3. Mendel performed his experiments on more characteristics than the four shown in the table. Why
was it important for him to look at more than one characteristic?
By looking at many different characteristics, Mendel could say for certain that these results
were true and not just a random chance or fluke. NOTE: Many of the same results have
been found in genetic studies of other plants and animals.
Pacific Cascade Science