Genetics Nonmendelian 150722002319 Lva1 App6891 PDF
Genetics Nonmendelian 150722002319 Lva1 App6891 PDF
Genetics Nonmendelian 150722002319 Lva1 App6891 PDF
W RW RW
W RW RW
Incomplete Dominance
CC – Curly hair x SS - Straight hair
C C
S CS CS
S CS CS
CS – Wavy hair x CS
Incomplete Dominance
Red - ____________
Blue - ____________
Purple - __________
Incomplete Dominance
2. What would happen if Spongebob crossed a
Poofkin with red flowers with a Poofkin with blue
flowers.
a. Give the phenotypes and genotypes for the
offspring.
b. How many of the plants would be have red
flowers? _____ %
c. How many of the plants would have purple
flowers? ______ %
d. How many of the plants would have blue
flowers? ______%
Incomplete Dominance
3. What would happen if SpongeBob crossed
two Poofkins with purple flowers?
a. Give the phenotypes and genotypes for the
offspring.
b. How many of the plants would be have red
flowers? _____ %
c. How many of the plants would have purple
flowers? ______ %
d. How many of the plants would have blue
flowers? ______%
Incomplete Dominance
4. What would happen if SpongeBob crossed a
Poofkins with purple flower with a Poofkin with
blue flower?
a. Give the phenotypes and genotypes for the
offspring.
b. How many of the plants would be have red
flowers? _____ %
c. How many of the plants would have purple
flowers? ______ %
d. How many of the plants would have blue
flowers? ______%
Incomplete Dominance
A A
B AB AB
B AB AB
Codominance
IA = IB > i
IAi IBi
IAIB
Inheritance of Rh Factor
Phenotype Genotype* Gene Antibodies
Product Present
Rh Positive RR or Rr Rhesus Protein None
Rh Negative rr None None
unless
exposed
Sperm
M m
1:2
MM Mm
M (early ratio
embryonic (Manx) of
death)
Lethality in Manx Egg kittens
mm that
cats causes altered m Mm (non-Manx)
ratio (Manx) are
born
2:1 ratio from cross between
two yellow mice results
from a lethal allele.
Hierarchy of Dominance
Dad C x Mom C
Wavy Curly
Allele S S’
Gene Product Hemoglobin A Hemoglobin S
Cell Shape Round Sickled under
low O2 tension
Response to Susceptible Resistant in SS’
Malaria genotype
Polygenic Traits
Definition
• Some traits are determined by the combined
effect of two or more pairs of alleles. These traits
are called polygenic traits.
• Pepper Color
Gene 1: R=red
r=yellow
• Chicken Combs:
• Hair Color
– Hair color is controlled by alleles on
chromosomes 3, 6, 10, and 18.
– The more dominant alleles that appear in the
genotype, the darker the hair!
Polygenic inheritance
• In the nucleus of
every body cell
there are 46
chromosomes
• 22 homologous pair
and one pair of sex
chromosomes
Female and Male Sex Chromosomes
Red Green Colour Blindness
• Inability to
distinguish between
red and green
• A red green colour
blind person does
not see the number
29 on the right
• In humans normal
vision is completely
dominant to red-
green colour
blindness
Genetics of Colour Blindness
• Normal vision C
• Red-green colour blindness c
• Heterozygous females are called carriers
• Work out the genotypes of the following
family tree
Answers
• Carrier mother XCXc
• Nomal father XCY