Question

Part 1: Incomplete Dominance—Predicting Flower Color in Snapdragons
Snapdragons are popular garden plants that produce brightly colored flowers. When a plant that is homozygous for white flowers is crossed with a plant that is homozygous for red flowers, all offspring are pink. Snapdragons are an example of a plant that exhibits an inheritance pattern called incomplete dominance.

1. Determine the genotype of each parent plant and write them below. Use W to indicate the allele for white flowers and R to indicate the allele for red flowers.
Answer:

Genotype of homozygous parent plant with white flowers:

Genotype of homozygous parent plant with red flowers:

Answer 1

@SmokeyBrown

Answer 2

So, homozygous means that both alleles that influence a trait are the same. So, a homozygous white plant would have a WW genotype, and a homozygous red plant would have a RR genotype

Answer 3

that's for number 1 right

Answer 4

Yup

Answer 5

ok for number 2

Answer 6

Genotype of homozygous parent plant with white flowers:

Genotype of homozygous parent plant with red flowers:

Answer 7

That's the same one

Answer 8

oh that answer for all three of those questions ?

Answer 9

2. Next, think about the gametes each parent plant will produce. List the alleles in each gamete.
Answer:

Parent plant with white flowers:
Gamete 1:
Gamete 2:
Gamete 3:
Gamete 4:

Parent plant with red flowers:
Gamete 1:
Gamete 2:
Gamete 3:
Gamete 4:

Answer 10

Hm, since the parents only have one type of allele, the red plant would only produce gametes with R alleles and the white plant would only produce gametes with W alleles, right?

Answer 11

right all are W's

Answer 12

The two parent plants are the P generation, or parent generaton. Create a Punnett square to show their offspring, the F1 generation.

Answer 13

So, you'd draw the punnett square with the red parent contributing R and R, and the white parent contributing W and W

Answer 14

the punnett square looks like this

https://middleschoolscienceblog.files.wordpress.com/2015/02/spongbob-genetics-public1.jpg?w=636

R R and W W i'm trying to figure how to draw it like

Answer 15

You can have RR along the top and WW along the side. Then, fill in the squares with the combination of R and W that are next to that square

Answer 16

on the left side: RW, Rw

on the right side: Rw, rw

right ?

Answer 17

is it like this

Answer 18

What pattern do you notice in the genotypes of the F1 generation snapdragons?

Answer 19

Yeah, that's right.
Do you notice any pattern in the genes inside the square?

Answer 20

yes and it's red

Answer 21

it's the colors of the snapdragons

Answer 22

Oh, sorry, all of the genotypes should be RW
The snapdragons have "incomplete dominance", so instead of one allele dominating the other, if there is a combination of different alleles, RW, they combine. That's why all the offspring are pink

Answer 23

oh that's right

Answer 24

What are the phenotypes of the F1 generation snapdragons ?

Answer 25

All F1 plants are RW, a combination of red and white.

Answer 26

correct all is RW ?

Answer 27

Yeah that's right

Answer 28

Part 2: Incomplete Dominance—Predicting Flower Color in F2 Generation Snapdragons

Now, set up a cross of the offspring of the F1 generation and predict the traits of the F2 generation.

1. What are the genotypes of the F1 parent plants?.
Answer:
Type your answer here.
• Genotype of F1 parent plant 1:
• Genotype of F1 parent plant 2:

Answer 29

Ww right ?

Answer 30

Well, we're still looking at the F1 generation, so they would all be RW

Answer 31

Next, think about the gametes each parent plant will produce. List the alleles in each gamete.
F1 parent plant 1:
• Gamete 1:
• Gamete 2:
• Gamete 3:
• Gamete 4:
F1 parent plant 2:
• Gamete 1:
• Gamete 2:
• Gamete 3:
• Gamete 4:

Answer:

Answer 32

I think, for each plant, they'd produce 2 R and 2 W

Answer 33

Create a Punnett square showing a cross between the two F1 parent plants. Their offspring are the F2 generation.

Answer 34

It would be the same as before, except instead of RR and WW, the alleles on the outside would be RW and RW

Answer 35

like this

https://image.slidesharecdn.com/punnettsquare-131107003335-phpapp02/95/punnett-square-12-638.jpg?cb=1383784462

Answer 36

What are the genotypes of the F2 generation?

Answer 37

Not quite, that's the punnett square for the original parents.
Like I said, the square for the F1 generation has RW on the top and RW on the side, instead of RR on the top and WW on the side

Answer 38

what about in the inside

Answer 39

You fill in the inside of the square with whatever allele intersects with it

Answer 40

oh i got it RW in the inside

Answer 41

What are the genotypes of the F2 generation?

Answer 42

Ok, so the punnett square has 4 squares inside it. Each smaller square takes an allele from above and an allele from the left. The combination of those two alleles is what goes inside the box.

Answer 43

Now, how would you fill in the boxes of this punnet square?

Answer 44

RW

Answer 45

So, all four boxes would have a different combination of R and W, depending on which is on top and which one is on the side

Answer 46

RR

Rr

rr

Answer 47

Not quite, no. I'll draw it out for you

Answer 48

ok gotcha

Answer 49

What are the genotypes of the F2 generation?

Answer 50

?

Answer 51

WW, WR, RR FOR THE genotypes ?

Answer 52

Yeah, that's right

Answer 53

Calculate the percentages of the phenotypes of the F2 generation.

Answer 54

So, one of them is RR, one is WW, and two are RW. What would the percentages be?

Answer 55

White-WW-1/4
Pink-WR- 2/4
Red-RR- 1/4

Answer 56

is that right somehow

Answer 57

Oh, yeah, that's right. You just have to convert them to percentages

Answer 58

White-WW-14%
Pink-WR- 24%
Red-RR- 14%

correct ?

Answer 59

Not quite. 1/4 would be equal to 25%, and 2/4 would be 1/2 or 50%

Answer 60

that's right

Answer 61

What are the phenotypes of the offspring from this cross?

Answer 62

So you already kind of answered this. You know that WW is white, RR is red and RW is pink

Answer 63

Imagine that you are studying two parents who are considering having children. One parent is has the genotype IAi and the other has the genotype IBi. Create a Punnett square to calculate the possible genotypes of their children. Answer? Part 3 Punnett?
Part 3: Multiple Alleles—Predicting Blood Types of Offspring
As you read in the online lab, human blood type is determined by multiple alleles that show a type of inheritance called codominance. Recall that the alleles that determine blood type are IA, IB, and i. IA and IB are both dominant over i, while neither IA nor IB is dominant when they combine. Use this table to help you determine the genotypes associated with each blood type.
Blood Type Allele Possible Genotype(s) Possible Allele(s)
A IA AA or AO IAIA or IAi
B IB BB or BO IBIB or IBi
AB IAIB AB IAIB
O i OO ii

Answer 64

the answer is this i believe

https://d2jmvrsizmvf4x.cloudfront.net/xN1s0qZCRUuXh8Z2ptPL_Screen%2BShot%2B2017-12-04%2Bat%2B4.44.53%2BPM.png

Answer 65

I think that is correct

Answer 66

Look at the table at the beginning of Part 3. What are the possible phenotypes (blood types) of the children ?

Answer 67

1/4 chance of each AB, A, B, and O

correct ?

Answer 68

Yes, I think that's right

Answer 69

Part 4: Sex-Linked Inheritance—Predicting Color Blindness in Offspring
Recall that females have two X chromosomes: one from the mother and one from the father. Males have one X chromosome and one Y chromosome; the X chromosome comes from the mother, and the Y chromosome comes from the father. Traits associated with genes located on the sex chromosomes are called sex-linked traits.
Individuals with the sex-linked condition called red-green color blindness do not perceive the colors red and green. Red-green color blindness is caused by the recessive allele b and is carried on the X chromosome. The dominant allele for normal color vision is B. When an X chromosome contains the dominant allele, the allele is written as . When an X chromosome contains the recessive allele, the allele is written as X^b.

1. What is the genotype of a male with red-green color blindness?
Answer:

Answer 70

XY, X chromosome

Answer 71

Yeah, the X chromosome would have the b allele, for the recessive colorblindness trait

Answer 72

or X n Y

Answer 73

is that one right

Answer 74

Well, going by the notation that he question uses, I think it'd be X^bY

Answer 75

2. What is the genotype of a female who is not color-blind but is a carrier of red-green color blindness?
Answer:

Answer 76

For that one, one of the X chromosomes has the colorblind gene, but the other X chromosome does not

Answer 77

XBXb for the female

Answer 78

or b

Answer 79

Yeah XBXb should be right

Answer 80

Even though red-green color blindness is a recessive trait, can a female have red-green color blindness? Explain.

Answer 81

I would say yes. If the genotype is XbXb, then the female would have color blindness

Answer 82

A man who is color-blind marries a woman who is not color-blind and is not a carrier of the allele for color blindness. Create a Punnett square to predict the possible genotypes of their children.

Part 4 Punnet Square

Answer 83

Well, the man would have a XbY, and the woman would have XBXB. So, you can use that to construct your punnett square

Answer 84

like this

https://slideplayer.com/slide/10574642/36/images/52/Key%3A+Cross%3A+XB+%3D+normal+vision+XBXb+x+XbY+Xb+%3D+colorblindness+XBXb.jpg

Answer 85

https://www.learner.org/interactives/dna/images/genetics6b.gif

Answer 86

Kind of, except the man should have XbY, not XBY. The woman should have XBXB, not XbXb

Answer 87

Will all of the female children be carriers of the color-blind allele, or will none be carriers? Explain.

Answer:

Answer 88

??

Answer 89

Oh, they'd all be carriers. The only possible combination would be XBXb

Answer 90

Will all of the male children be color-blind, or will none be color-blind? Explain

Answer:

Answer 91

?

Answer 92

None of the male children would be colorblind, since the only possible combination would be XBY