In the F2 gen 1/4 was short and 3/4 was tall.
In Mendel's cross for stem height, how did plants in the F2 generations differ from the F1 plants?
because tall is a dominant allele
Why is a pea plant that is a hybrid still tall?
dominant, recessive
A __________ allele can mask a ___________ allele.
He spent 8 years studying pea plants and discovered patterns in the way characteristics pass from one generation to the next.
What did Mendel observe?
lost", one fourth
In the F2 generation the ____________ form of the trait always reappeared in about ___________ of the plants.
pairs
The factors that control traits exist in ________.
If both parents contributed a recessive allele, then the recessive form of the trait reappears.
Under what conditions would the recessive form of a trait reappear?
Tall is the dominant allele
Why is a pea plant that is a hybrid for stem height tall?
A gene describes the factors that control a trait and those factors are represented by dominant and recessive alleles (gene vs allele slide)
How is a gene different from an allele?
No because short is recessive and if a dominant gene were present it would be tall. A hybrid will always display the dominant trait.
Can a short pea plant be a hybrid for the trait of stem height?
F2 = GG, Gg, Gg, gg
In each plant where a G is present, those plants are green pods - Green is dominant. In the fourth plant - gg - no dominant allele so yellow pod.
**********Mendel crossed two pea plants: one with green pods and one with yellow pods. The F1 generation all had green pods. What color pods did the F2 generation have? Explain.
The alleles for this plant are TT. In any cross for height, the offspring would be tall because it is a purebred dominant plant so any offspring would have a dominant allele for height (T) that would mask a recessive allele.
*********The plant below (tall pea plant) is purebred for height (tall). Write the alleles of this plant. In any cross for height, what kind of offspring will this plant produce? Why?
Dominant alleles represent the trait that always shows up in an organism when this allele is present. Recessive alleles represent the trait that is hidden when a dominant allele is present.
How dominant alleles and recessive alleles differ?
cross pollination
From P to F1 what kind of pollination?
self pollination
From F1 to F2 what kind of pollination?
Probability
a number that describes how likely it is that an event will occur
genetic cross
In a _________ _________, the combination of alleles that parents can pass to an offspring is based on probability
25%
Suppose 3 out of 12 coins landed with tails up. How can you express this as a percent?
heterozygous, homozygous dominant, homozygous recessive
Label the following as homozygous dominant, homozygous recessive, or heterozygous: Tt, TT, tt
An organism can look the same but one could be heterozygous and the other could be homozygous dominant
Explain how two organisms can have the same phenotype but different genotypes.
you can see an organism's phenotype but their genotype is the alleles, which you can't see
What is the difference between genotype and phenotype?
Phenotype
Is a tall stem an example of a genotype or a phenotype?
You can try to predict what traits an offspring will inherit using probability.
How is Probability Related to Inheritance?