Download Complex Inheritance and Human Heredity

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Date
Complex Inheritance and Human Heredity
Biology/Life Sciences 3.a Students know how to predict the
probable outcome of phenotypes in a genetic cross from the
genotypes of the parents and mode of inheritance (autosomal
or X-linked, dominant or recessive).
Section 11.2 Complex Patterns of Inheritance
Main Idea
Details
Skim Section 2 of the chapter. Write two questions that come to
mind from reading the headings and illustration captions.
1.
How do gametes form? meiosis
Why do we need gametes? to reproduce and pass alleles on to offspring.
2.
New
Vocabulary
gamete
New
Vocabulary
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
autosomes
Use your book or dictionary to define gamete.
a mature sex cell with a haploid number of chromosomes sperm or egg
23 v shape
Use your book or dictionary to define each term.
pair # 1 - 22, not pair 23 (XX or XY)
any chromosomes that are not sex chromosomes
codominance
inheritance pattern where phenotypes of both homozygote parents
ex. S S' prime
sickle cell trait
are produced in heterozygous offspring; both alleles are expressed
epistasis
interaction of alleles with one allele masking the effects of the other
ee hides the B
ex. dog fur color, this is a form of polygenic
incomplete dominance
red and white flower
makes pink heterozygote
inheritance pattern where the phenotype of a heterozygote is
Rr = pink
RR or rr
intermediate between those of the two homozygotes; neither allele
of the pair is dominant but combine and display a new trait
multiple alleles
presence of more than two alleles for a genetic trait
A B or O
blood types are the best example of multiple alleles.
polygenic trait
skin color
AaBbCc
sex chromosomes
pair #23
XX=female
XY = male
sex-linked traits
inheritance pattern of a trait controlled by two or more genes; genes
may be on the same or different chromosomes
the chromosomes that determine the sex of an individual and
carry sex-linked characteristics
traits controlled by genes located on sex chromosomes
X-linked, hemophilia
Complex Inheritance and Human Heredity
111
Name
Date
Section 11.2 Complex Patterns of Inheritance
Incomplete
Dominance
I found this information
.
on page
SE, p. 302
RE, p. 119
Details
Analyze the ratios of offspring of the following snapdragon pairs.
Hint: To write the genotypes, designate the dominant red allele as R
and the recessive white allele as r.
Phenotype
Parent
Flowers
Genotypes of
Parent Flowers
red and
white
RR ⫻ rr
pink and
white
Rr ⫻ rr
red and
pink
pink and
pink
Codominance
I found this information
.
on page
SE, pp. 302–303
RE, pp. 119–120
Multiple Alleles
I found this information
.
on page
SE, p. 304
RE, pp. 120–121
112
Punnett Square
Ratio of
Offspring
R
Rr
Rr
4 pink
r
r
R
Rr
Rr
R
Rr
r
rr
2 pink: 2 white
r
r
Rr
rr
R
R
RR
R
RR
r
Rr
Rr
R
r
R
RR
Rr
r
Rr
rr
RR ⫻ rr
Rr
Rr ⫻ Rr
2 red: 2 pink
1 red: 2 pink:
1 white
Predict the results if two people who are heterozygous for sicklecell anemia but lead normal lives have a child.
50% SS' (trait)
25% SS (normal)
The child might have no alleles for the disease, might be heterozygous,
or might be homozygous for the disease. 25% S'S' (disease)
Identify the blood group that results from each combination of
genotypes. The first one has been done for you.
Possible Genotype Combinations
Phenotypes
A and A
A
A and B
AB
A and O
A
B and B
B
B and O
B
O and O
O
Complex Inheritance and Human Heredity
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Main Idea
(continued)