Transcript Rr - cloudfront.net

Look over meiosis notes for 5 minutes.
You will take a quiz on your laptop over
Meiosis today!
After Quiz, get out spiral notebook
Predicting Inheritance
MENDELIAN GENETICS
Genetics
Gregor Mendel
 The “father of
genetics.”
 First person to
successfully predict how
traits are transferred
from one generation to
the next.
 Used pea plants to show
how genes were passed
down
Genetics Vocabulary
 Homozygous/Purebred: Two alleles for a
trait are the same Examples: RR, rr, FF, qq,
mm
 Heterozygous/Hybrid: Two alleles for a trait
are different Examples: Rr, Ff, Qq, Mm
Heterozygous or Homozygous?
 TT
 Pp
 dd
 Ff
 Tt
 FF
Heterozygous or Homozygous?
 TT- homozygous
 Pp- heterozygous
 Dd- homozygous
 Ff- heterozygous
 Tt- heterozygous
 FF- homozygous
What are allels?
 Alleles: genes carried in
gametes
 Each organism has two
alleles that control each of
its traits, one from father
and one from mother.
 Example: PP, Pp, pp
Genotype versus Phenotype
 Genotype:
Individual’s genes
 (genetic info!)
 Phenotype:
Individual’s physical
appearance
Dominant vs. Recessive
 Dominant trait
is always
expressed
 RR or Rr
 Recessive trait
is only observed
when
homozygous.
 rr
Rule of Dominance
 In Squidward’s family, a blue body color (B) is
dominant to green (b). Determine the
phenotype for each genotype below based on
this information.
 BB - ?
 Bb - ?
 bb - ?
Rule of Dominance
 In Squidward’s family, a blue body color (B) is
dominant to green (b). Determine the
phenotype for each genotype below based on
this information.
 BB- blue
 Bb-blue
 bb- green
Let’s put this into action!
 SpongeBob is known for his big round eyes
(R), which are dominant over an oval eye
shape (r). If he is heterozygous for his round
eye shape and marries a woman with oval eye
shape, what type of eyes might his kids have?
 Step 1: List the genotypes of the parents:
 Heterozygous round eyes: ____
 Oval eyes: ____
Step 2: Punnett Square
Heterozygous round eyes: Rr
Oval eyes: rr
Step 3: Punnett Square
Heterozygous round eyes: Rr
Oval eyes: rr
R
r
r
r
Step 4: Punnett Square
Heterozygous round eyes: Rr
Oval eyes: rr
R
r
r
Rr
rr
r
Rr
rr
Predictions & Ratios
 Based on the results of the Punnett Square,
identify the possible offspring combinations.
 % Homozygous round eyes (RR) ___________
 % Heterozygous round eyes (Rr) ___________
 % Homozygous oval eyes (rr)___________
Predictions & Ratios
 Based on the results of the Punnett Square,
identify the possible offspring combinations.
 Homozygous round eyes (RR) _0%_________
 Heterozygous round eyes (Rr) ___50%______
 Homozygous oval eyes (rr)__50%_________