Genetics Review
Who is the “Father of Genetics”?
Gregor Mendel
What organism did Mendel use to study genetics?
Pea Plants
Transmission of characteristics from parents to offspring is called ___________________.
_____________ is the study of how characteristics are passed on from one generation to the next.
heredity
Genetics
__________________ = An allele that IS MASKED BY the presence of another allele
Recessive
The appearance of an organism is
its _____________phenotype
Another name for heterozygous
hybrid
The diagram at the rightis called a _____________Punnett square
__________________ = An allele that MASKS the presence of another allele
Dominant
A recessive gene is represented by a _________________ letter.lower case
_______________
are different gene
choices for a trait.
Alleles
A dominant gene is represented by a ____________ letter.(usually the first letter of the trait)
capital
When both alleles in the pair are the SAME the organism is ______________ Homozygous or purebred
When both alleles in the pair are DIFFERENT the organism is
_________________Heterozygous or hybrid
monohybridA cross that involves only 1 traitis called a ____________ cross.
Homozygous (HO) or Heterozygous (HE)?
TT ____Yy ____Hh ____Mm ____
Ee ____kk ____BB ____ ZZ ____
HO
HE
HE
HE HO
HO
HO
HE
Determine the Phenotype:
Pink flowers are dominant to red flowers
PP _____________Pp _____________pp _____________
Brown eyes are dominant to green eyes
BB ____________Bb ____________bb ____________
Pink
Pink
Red
Brown
Green
Brown
For each phenotype, list the genotype:
Straight hair is dominant to curly.
____________ straight____________ straight____________ curly
Square heads are dominant to round heads.
____________ square____________ square____________ round
SS
Ss
ss
SS
Ss
ss
In guinea pigs, black fur (B) is dominant over brown fur (b).
If a black Guinea pig is crossed witha brown Guinea pig and the littercontains a brown baby, the genotypeof the black parent is probably
BB Bb bb
Bb; Must have one B to be black must have one b to pass on to baby
T = Tall
t = short
The genotype of the offspring from the
cross at the right is _________.
Their phenotype is _________.
Tt
tall
The parents in this cross are _____________ Homozygous Heterozygous
Heterozygous
If G is dominant for green pods and g is recessive for yellow pods, what percentage of the offspring will have green pods? _______% 75
GG Gg
Gg gg
G gG
g
What are the possible phenotypes of their offspring?
(% and color)
Red throats (R) are dominant over white (r)throats in Goonie birds.
Make a cross between a PURE RECESSIVE and a HETEROZYGOUS Goonie bird.
50% red throats 50% white throats
Rr rr
Rr rr
R r
r
r
What are the possible phenotypes of their offspring?
(% and color)
Black eyes (B) are dominant over red eyes (b) in rats.
Make a cross between two HETEROZYGOUS rats.
75 % black eyes 25% red eyes
B b
B b
BB Bb
Bb bb
The parents in this cross are _____________ Homozygous Heterozygous
Homozygous
If W is dominant for long wings and w is recessive for short wings, what percentage of these offspring will have short wings? _______%
0% only ww makes it short
What is the probability the offspring will have straight tails?
In Reebops curly tails (T) are dominant over straight tails (t).
Make a cross between a HOMOZYGOUS DOMINANT and a HOMOZYGOUS RECESSIVE Reebop.
0% All will be Curly tailed (Tt)
Tt Tt
Tt Tt
T T
t
t
What will the offspring be like?
(% and color)
Purple (P)is the dominant color for monsters. Yellow is recessive (p).Make a cross between a HOMOZYGOUS purple and a yellow monster.
100% purple
Pp Pp
Pp Pp
P P
p
p