Download Who was Gregor Mendel

Who was Gregor Mendel?
Mendel’s Principles of Inheritance
GeneChromosome
Theory
(not really
Mendel’s)
Hereditary
information is
transmitted from
parents to
offspring as
___________
found on
chromosomes.
These genes
determine an
individual’s traits.
Law of Dominance
(complete
dominance)
Law of Segregation
(of alleles)
Law of Independent
Assortment
In cases in which two
or more forms
(____________) of a
gene for a single
_____________ exist,
some forms of the
gene may be
__________________
and cover up others
that are
____________________.
In most
_________________
reproducing organisms,
each adult has ________
copies of each
_________: one from
each parent. These
genes are
________________________
from each other when
gametes are formed.
The alleles for different
genes usually
segregate
_______________________
of one another.
Dominant Alleles vs. Recessive Alleles
The dominant allele always _______ or __________ the
recessive allele. It is the one that is ___________ and is
what we see.

Dominant alleles are represented with __________
letters.
 The recessive allele is “weaker” and gets ______________ up by the
dominant allele. It is not expressed unless an individual inherits ______copies of the alleles.
o Recessive alleles are represented with l_________________letters .
Dominant Traits: tall stems, green pods, yellow seeds, round seeds
Recessive Traits: short stems, yellow pods, green seeds, wrinkled seeds
Mendelian Genetics Guided Practice
1)
2)
3)
4)
5)
What is a gene? ________________________________________________________________________________
What does a gene code for? ___________________________________
What is a phenotype? __________________________________________________________________________
What is an allele? ______________________________________________________________________________
How many alleles does a person have that makes up his or her genotype? _________
For the chart below, use the information provided to practice assigning letters to represent alleles.
Remember that it is good practice to use the letter of the dominant for of the trait.
Dominant Traits: tall stems, green pods, yellow seeds, round seeds
Recessive Traits: short stems, yellow pods, green seeds, wrinkled seeds
Trait
Height
Pod Color
Seed Color
Seed
Shape
Dominant
Recessive
1) For each genotype below, indicate whether it is heterozygous (He) or Homozygous (Ho).
a. TT _______ b. Bb _______ c. Dd _______ d. LL ______ e. gg _______
b. Circle the genotypes above that would be considered purebred.
c. Draw a square around the genotypes above that would be hybrids.
2) Determine the phenotype for each genotype using the information provided.
a. Brown hair is dominant to blonde hair.
e. Brown eyes are dominant to blue eyes.
i. BB ________________________
i. BB _________________________
ii. Bb ________________________
ii. Bb _________________________
iii. bb ________________________
iii. bb _________________________
b. Which genotype is homozygous brown? _____
f. Which genotype is heterozygous? ____
c. Which genotype is homozygous blonde? _____
g. Which genotype is homozygous blue?
d. Which genotype is heterozygous? _____
h. Which genotype is homozygous
brown? _____
3) For each phenotype, give the genotypes that are possible.
a. Tall plants (T) are dominant to short plants (t).
b. Purple (P) flowers are dominant to
white flowers (p).
i. Tall = _______________________
i. Purple = ________________________
ii. Short = ______________________
ii. White = __________________________
4) For the next 3 problems, identify the genotype of each parent.
a. Round seeds are dominant to wrinkled seeds. [Round = RR or ____, wrinkled = _____] Plant
A is a wrinkle-seed plant, and it is crossed with Plant B which is homozygous for round seeds.
i. Genotype of Plant A: _______________
ii. Genotype of Plant B: _______________
b. Attached earlobes are dominant to detached earlobes. Sharon has detached earlobes.
Bob is heterozygous for attached earlobes. [Attached = ____ or ____, Detached = ____]
i. Genotype of Sharon: __________________
ii. Genotype of Bob: _____________________
c. Green seeds are dominant to yellow seeds. Two plants that are heterozygous for green
seeds are crossed. [Green = ____ or ____, Yellow = ____]
i. Genotype of 1st plant: ____________________
ii. Genotype of 2nd plant: ____________________
What will be the genotype of the offspring? __________________