Meiosis Draw a cell in interphase before and after replication with a diploid number 4.
replication
What would the haploid number of gametes be?
An aquatic arthropod called Cyclops has antennae that are either smooth (a) or barbed(A). The allele for barbs is dominant. In the same organism, long (T) tails are dominant to short (t) tails.
Question: A Cyclops that has a short tail and smooth antennae is crossed with one that is heterozygous for both traits.
Genotype Ratio ______________________________Phenotype Ratio ______________________________
Genotype Ratio:
1: AaTt: 1 Aatt: 1 aaTt : 1 aatt
Phenotype Ratio : 1 Barbed, Long tail : 1 Barbed, short tail: 1 smooth, long tail: 1 smooth, short tail
A curly haired person and a straight haired person mate and all their offspring have wavy hair (note that wavy hair is a phenotype an intermediate that of the curly and straight haired individuals).
Genotype Ratio: __________?____________
Phenotype Ratio: __________?____________
Genotype Ratio (letters)1 CC : 2 CS : 1
SS
Phenotype Ratio ( physical appearance)1 Curly: 2 wavy : 1 straight
Who is the “Father of Genetics”?
Gregor Mendel
When 2 alleles DON’T BLENDbut BOTH SHOW TOGETHERlike in A B blood type, it is called_______________
Codominance incomplete dominance
codominance
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 allelethat 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
Red and white flowers producingpink offspring is an example of
_______________________ Codominance incomplete dominance
DOMINANT
Incomplete dominance
A recessive gene is represented by a _________________ letter.lower case
What phenotypic ratio would youexpect to see in offspring from amonohybrid cross of 2 heterozygous parents?
3:1 Dominant:recessive
A dominant gene is represented by a ____________ letter.(usually the first letter of the trait)
capital
When a heterozygous individual showsa blending of 2 alleles instead of one being dominant over the other it is called___________ ____________.Incomplete dominance
When both alleles in the pair are the SAME the organism is _______________ or __________
9:3:3:1
HOMOZYGOUS PURE
What phenotype ratio is a cluethat there has been a dihybrid crossbetween 2 heterozygous parents?
R = red flowers r = white flowers
Red
pink
An Rr organism would have ____________ flowers if this trait was COMPLETELY DOMINANT.
An Rr organism would have ____________ flowers if this trait was INCOMPLETELY DOMINANT.
An Rr organism would have ______________ flowers if this trait was CODOMINANT.
BOTH red & white
What are Mendel’s 2 laws of heredity?
Law of SegregationLaw of Independent Assortment
F1
The offspring of the P1 generationare called the ____ generation
When both alleles in the pair are DIFFERENT the organism is
_________________ or _____________HETEROZYGOUS HYBRID
monohyridA cross that involves only 1 traitis called a ____________ cross.
T = Tall
t = short
The genotype of the offspring from the
cross at the right is _________.
Their phenotype is _________.
Tttall
Which of the following genotypesis homozygous?
TT Ww Bb rr mm BB Tt
TT rr mm BB
pureAnother name for homozygous is________.
Which of these Punnett squares would you
use to predict the offspring of a DIHYBRID cross?
This one!
In the cross at the
right __________
is dominant for flower color.
red
Tt Mm Rr
Which of the following genotypesis from a heterozygous organism?
Tt SS bb Mm Rr kk
A gene is a segment of _______that codes for a trait.
DNA
meiosis
The Law of Segregation and theLaw of Independent Assortmentare the result of the movement ofchromosomes during ___________
mitosis meiosis
Crossing a red haired horse with a white haired horse produces a roan colored horse.
(Both alleles for hair color show together). This kind of inheritance is called ___________________Co-dominance
What type of genotype is used to make a test cross?
Homozygous recessive
BT bt bT Bt
What type of gametes can this organism produce?
BbTt
______ ______ _______ _______
In guinea pigs, black fur (B) is dominant over brown fur (b).
If a black Guinea pig is crossed witha brownGuinea 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
Which of these Punnett squares would you
use to predict the offspring of a MONOHYBRID cross?
This one!
Crossing individuals from the P1 generation produces the
____ generation.F1
DNAA gene is a segment of ______.
DNA PROTEIN RNA CARBOHYDRATE
L = Blue legs l = yellow legs
Blue
green
An Rr organism would have ____________ legs if this trait was COMPLETELY DOMINANT.
An Rr organism would have ____________ legs if this trait was INCOMPLETELY DOMINANT.
An Rr organism would have ______________ legs if this trait was CODOMINANT.
BOTH Blue & yellow
In a monohybrid cross of twoHETEROZYGOUS parents (Pp), you would
expect the offspring to be:
1 pp:3 PP 3 Pp:1 pp
1 PP:2 Pp:1 pp
1 PP:2 Pp:1 pp all Pp
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
B b
B
b
The genotype of the offspring in the blue box is _______
bb
The offspring in the blue box is homozygous heterozygous
homozygous
B b
B
b
In guinea pigs black fur (B) is dominant over brown fur (b). The Punnett square for a cross between a HETEROZYGOUS black guinea pig and a PURE brown guinea pig would look like
This is the Correct setup
Heterozygous = BbPure brown = bb
B B
b
b
B b
b
b
B b
B
B
Another name for pure is _________________homozygous
A oA AA Ao
B AB Bo
F A & B are codominant
The alleles for blood type show 2 kinds of inheritance..
The following statements are TRUE or FALSE?
A is dominant over B.O is dominant over A.A is dominant over O.B and A are co-dominantA is incompletely dominant over O.O is recessive to A and to B
F O is recessive to both A & B TTFT
An organism has the genotype Xy.
What are the possible sperm it can produce? ______ ______
THINK ABOUT IT:If females have an XX genotype and can only give X genes, which parent is the one that determines whether the baby is a boy or girl?
X y
Father ;The mother always gives an XIf the father gives a y, it’s a boy.If the father gives an X; it’s a girl.
If you cross a homozygous RED flowered four o’clock plant with a homozygous WHITE flowered plant, ALL of the offspring produced have PINK flowers.
This type of inheritance in which the heterozygote (Rr) shows a blending of traits is called __________.
A. Dominant/recessive inheritance B. Co-dominance
C. Incomplete dominance
Incomplete dominance
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
Who is the “Father of Genetics”?
Gregor Mendel
Which of the following genotypes could be from a HETEROZYGOUS organism?
TT Rr Ww bb XX Ss
Rr Ww Ss
What kind of cross is this?
Pure dominant X pure recessiveHeterozygous X heterozygousHeterozygous X homozygousHybrid recessive X hybrid pure
Heterozygous X Homozygous
Another name for heterozygous is _______________hybrid
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
BT bt bT Bt
What type of gametes can this organism produce?
BbTt
______ ______ _______ _______
What type of gametes can this organism produce?
BBTT
______ ______ _______ _______BT BT BT BT
TR Tr tR tr
TR
Tr
tR
tr
Tall = T short = t R= round r=wrinkled seeds seeds
TtRr X TtRr
TTRR TTRr TtRR TtRr
TTRr TTrr TtRr Ttrr
TtRR TtRr ttRR ttRr
TtRr Ttrr ttRr ttrr
This is an example of a DIHYBRID cross.
Which pattern of phenotypes will be seen in the offspring?
9:3:3:1
How many offspring will be Short AND Round? ______
Short AND wrinkled? ______
3/16Recessive and dominant
Recessive and recessive HINT:9- dominant for both3- recessive and dominant3- dominant and recessive1- recessive and recessive
1/16
What do we call the offspring of the F1 generation?
F2
Which of the following genotypes could be from a HOMOZYGOUS RECESSIVE organism?
TT bb Rr Ww tt XX aa
bb tt aa
A a
A
a
The genotype of the offspring in the blue box is _______ homozygous heterozygous
heterozygous
How many of the offspring from this cross will show the dominant characteristic?
¾ (75%) – AA and Aa
G g
G GG Gg
g gg
G is dominant for green pods.g is recessive for yellow pods.
What is the genotype of the offspring in the shaded box?
Gg
What is the phenotype of the offspring in the shaded box?
Green pods
Which of the following is NOT TRUE?
Genotype determines phenotype Alleles are different forms of the same gene. Genotype is the way the genes make you look. Organisms with different genotypes
can have the same phenotype.
T
T
F
T
Tt and TT both look tall
What are the 3 different kinds of inheritance you learned about?
Dominant/recessiveIncomplete dominanceCo-dominance
Offspring of the P1 generation are called ______
F1
What are the probable blood types of the offspring?
What are the possible offspring of a cross between a blood type AB mom and a type O dad?
50% Type A 50% Type B
Ao Bo
Ao Bo
A B
O
O
Which of the following crosses would you expect to see a 9:3:3:1 ratio in the offspring?
SSYY X ssyy SsYy X SsYy ssYY X SSyy
SsYy X SsYy9:3:3:1 ratio is seen in dihybrid crosses
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
What genotype would a PURPLE dad have to be to make a yellow monster baby with a Purple (Pp) mom monster?
P p?
?
pp
Pp
Dad needs to have: a little p to give one to the baby a big P to be purple himself
Wilma and Fred are going to have a baby.Fred in AA and Wilma is oo.
What are the possible blood types of their baby?
100% will have A type blood
Ao Ao
Ao Ao
A A
o
o
Wilma and Fred are going to have a baby.Fred in AA and Wilma is oo.
What are the possible blood types of their baby?
100% will have A type blood
Ao Ao
Ao Ao
A A
o
o
RT rt rT Rt
What type of gametes can this organism produce?
RrTt
______ ______ _______ _______
What type of gametes can this organism produce?
WwGg
______ ______ _______ _______WG wg wG Wg
In a DIHYBRID HETEROZYGOUS cross the offspring that are
9/16 are _______________ for both traits.
3/16 are _____________ for one trait and _____________ for the other.
1/16 are _____________ for both traits.
Dominant
FILL IN THE BLANKS WITH THE WORDS Dominant OR Recessive
DominantRecessive Recessive
In this cross: TtRr X TtRt
What is the probability the offspring will be:
Tall AND white? ____/16
Short AND red? ____/16
Tall AND red? ___/16
Short AND white? ___/16
3
T = Tall R = redt = short r = white
3 9
1
In this cross: TtYy X TtYy
What is the probability the offspring will be:
short AND green? ____/16
Short AND yellow? ____/16
Tall AND green? ___/16
tall AND yellow? ___/16
1
T = Tall Y = yellow peast = short y = green peas
3 3
9
In this cross: YYRR X yyRRBe careful!
What is the probability the offspring will be:
Yellow peas AND white flowers? ____/16
Green peas AND red flowers? ____/16
Yellow peas AND red flowers? ___/16
Green peas AND white flowers? ___/16
0
Y = yellow peas R = red flowersy = green peas r = white flowers
0 16
0