Solved Genetics Pedigree Worksheet 1. Use the below pedigree ... - Free Printable

Let’s solve this step by step.

We are told that dimples (D) is dominant to no dimples (d). That means:
- If someone has at least one D allele → they have dimples.
- Only if someone has dd → they do NOT have dimples.

We’ll go person by person and assign genotypes based on their phenotype (whether they have dimples or not) and their family relationships.

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Step 1: Label known phenotypes from the pedigree

Looking at the first pedigree (Problem 1):

Filled symbols = have dimples
Open symbols = no dimples

So:

Generation I:
- #1: male, filled → has dimples → genotype? Could be DD or Dd
- #2: female, open → no dimples → must be dd
- #3: male, open → no dimples → dd
- #4: female, open → no dimples → dd

Wait — hold on! Look again. In Generation I, #3 and #4 are both open (no dimples), but in Generation II, #10 is filled (has dimples). How can two parents with no dimples (both dd) have a child with dimples? They can’t — because each parent can only give a “d” allele. So child would be dd → no dimples.

But #10 HAS dimples → contradiction?

Wait — let me recheck the image description.

Actually, looking back: In the first pedigree, #3 and #4 are both OPEN (no dimples), but their daughter #10 is FILLED (has dimples). That’s impossible if dimples is dominant and both parents are dd.

Unless... maybe I misread the shading?

Wait — let’s read the key again:

> Filled square/circle = has dimples
> Open = no dimples

And it says: “Dimples is dominant to no dimples”

So if #3 and #4 are both open → both dd → all children must be dd → no dimples.

But #10 is filled → has dimples → impossible.

This suggests there might be an error in my assumption — OR perhaps #3 or #4 is actually filled?

Wait — let me look again at the original problem text.

The user wrote:

“Use the below pedigree chart...”

And in the diagram description:

In generation I:
- #1: filled male
- #2: open female
- #3: open male
- #4: open female

Then generation II:
- #5: open male (child of 1&2)
- #6: open female (child of 1&2)
- #7: open male (child of 1&2)
- #8: open female (child of 1&2)
- #9: open male (child of 3&4)
- #10: filled female (child of 3&4) ← PROBLEM HERE
- #11: open male (child of 3&4)

Then generation III:
- #12: filled male (child of 8&9)
- #13: open female (child of 8&9)
- #14: filled female (child of 8&9)

Ah — here’s the issue: #10 is child of #3 and #4, who are both open (no dimples). But #10 has dimples. Since dimples is dominant, she must have at least one D allele. But if both parents are dd, they can’t give a D allele.

This is genetically impossible under standard Mendelian inheritance.

Unless… wait — maybe I misread which individuals are connected?

Let me reconstruct the pedigree logically.

Typically, horizontal line between two people = mating pair. Vertical lines down to children.

So:

- #1 and #2 are mates → children: #5,6,7,8
- #3 and #4 are mates → children: #9,10,11
- Then #8 and #9 are mates → children: #12,13,14

Yes.

Now, #3 and #4 are both open → no dimples → genotype dd.

Their child #10 is filled → has dimples → must be D_ (DD or Dd).

But how? Both parents are dd → can only pass d → child must be dd → no dimples.

Contradiction.

Unless... the trait is not fully penetrant? Or maybe there's a mutation? But for basic genetics problems, we assume simple dominance.

Perhaps the shading is reversed? Let me check the key again.

Key says:

> Filled square = male with dimples
> Filled circle = female with dimples
> Open = no dimples

And: “Dimples is dominant to no dimples”

So yes, filled = has dimples.

But then #10 cannot exist if #3 and #4 are both dd.

Unless... maybe #3 or #4 is actually filled? Let me double-check the user’s description.

User wrote:

“In the first pedigree:

I: 1(filled male), 2(open female), 3(open male), 4(open female)

II: 5(open),6(open),7(open),8(open) [children of 1&2]; 9(open),10(filled),11(open) [children of 3&4]

III: 12(filled),13(open),14(filled) [children of 8&9]”

So according to this, #10 is filled, parents #3 and #4 are open.

This is impossible.

Unless... wait a minute — perhaps "dimples" is recessive? But the problem says: “Dimples is dominant to no dimples”.

Maybe it's a typo in the problem? Or perhaps I need to proceed assuming that #10 must have gotten a D from somewhere — so maybe one of the parents is heterozygous?

But if #3 and #4 are open (no dimples), they must be dd.

Unless... the open symbol doesn't mean no dimples? No, the key says it does.

Another possibility: maybe #3 or #4 is not the biological parent? But that's not indicated.

For the sake of solving the problem as intended, perhaps we should assume that #3 and #4 are carriers? But they show no dimples, so if dimples is dominant, they can't be carriers — they must be dd.

I think there might be an error in the problem setup, but let's try to work around it.

Perhaps #10 is not the child of #3 and #4? But the diagram shows she is.

Wait — let's look at the second part of the question.

Question A: How many family members have dimples?

From the list:

Filled symbols: #1, #10, #12, #14 → that's 4 people.

Is that right? #1 (male, filled), #10 (female, filled), #12 (male, filled), #14 (female, filled). Yes, 4.

But #10's existence is problematic.

Perhaps in this context, we ignore the inconsistency and proceed.

Maybe "dimples" is recessive? But the problem explicitly says it's dominant.

Let me read the problem again carefully.

" Dimples is dominant to no dimples."

And key: filled = has dimples.

So for #10 to have dimples, she must have at least one D.

Her parents #3 and #4 have no dimples, so they are dd.

Impossible.

Unless... perhaps the open/filled is switched for some reason? But the key is clear.

Another idea: maybe #3 and #4 are not both open? Let me check the user's initial description.

User said: "3 4" with 3 being open male, 4 open female.

Perhaps in the actual image, #4 is filled? But user described her as open.

I think for the purpose of this exercise, we have to assume that the pedigree is correct and proceed, even if there's an inconsistency, or perhaps I'm missing something.

Let's try to assign genotypes ignoring the contradiction for now.

Start with what we know for sure.

Individuals with no dimples (open symbols) must be dd.

So:

#2: open female → dd

#3: open male → dd

#4: open female → dd

#5: open male → dd

#6: open female → dd

#7: open male → dd

#8: open female → dd

#9: open male → dd

#11: open male → dd

#13: open female → dd

Now, individuals with dimples (filled):

#1: male, filled → has dimples → genotype D_ (could be DD or Dd)

#10: female, filled → D_

#12: male, filled → D_

#14: female, filled → D_

Now, let's use family relationships.

First, #1 and #2 are parents of #5,6,7,8.

#2 is dd.

All children (#5,6,7,8) are dd (no dimples).

Since #2 gives d to all children, and children are dd, that means #1 must have given d to all of them.

So #1 must be Dd (because if he were DD, all children would be Dd and have dimples, but they don't).

So #1: Dd

#2: dd

Children: all dd — makes sense, since each gets d from mom and d from dad (dad is Dd, so 50% chance d, and in this case all got d).

Now, #3 and #4 are both dd.

Their children: #9, #10, #11.

#9: dd (open)

#11: dd (open)

#10: filled → has dimples → must be D_

But both parents are dd, so they can only give d alleles. So #10 should be dd, but she's not.

This is impossible.

Unless... perhaps #10 is adopted? Or there's a new mutation? But for basic genetics, we don't consider that.

Maybe the problem has a typo, and #10 is supposed to be open? But then why is she filled?

Another possibility: perhaps "dimples" is recessive, and the problem statement is wrong? But it says "dominant".

Let's look at the next generation.

#8 and #9 are mates.

#8: open → dd

#9: open → dd

Their children: #12 (filled), #13 (open), #14 (filled)

#13 is open → dd

#12 and #14 are filled → have dimples → must be D_

But both parents are dd, so they can only give d alleles. So all children should be dd → no dimples.

But #12 and #14 have dimples — again impossible.

This suggests that either:

1. The trait is recessive, not dominant.

2. There's a mistake in the pedigree shading.

3. We need to assume that some individuals are heterozygous even if they show the recessive phenotype, which contradicts dominance.

Given that, perhaps the problem meant that "no dimples" is dominant? But it explicitly says "Dimples is dominant to no dimples".

Let's read the problem once more:

"Dimples is dominant to no dimples."

And key: filled = has dimples.

But in the pedigree, when both parents have no dimples (dd), they have children with dimples, which is impossible.

Unless... for #8 and #9, if they are both dd, children can't have dimples.

But #12 and #14 do.

So the only logical conclusion is that #8 and #9 are not both dd.

But they are open symbols, so they should be dd.

Unless the open symbol means something else? No.

Perhaps "open" means has dimples? But the key says otherwise.

I think there might be a fundamental error in the problem, but for the sake of answering, let's assume that the filled symbols indicate the dominant trait, and we'll work backwards.

For #12 and #14 to have dimples (D_), and their parents #8 and #9 are both open (which should be dd), but if they are dd, children can't have D.

So perhaps #8 and #9 are not dd.

But they are open, so if dimples is dominant, open means no dimples, so dd.

Deadlock.

Another idea: perhaps the dominance is reversed in interpretation.

Let me try assuming that "no dimples" is dominant, and "dimples" is recessive.

But the problem says: "Dimples is dominant to no dimples."

So that can't be.

Perhaps in the pedigree, the filled symbols are those without dimples? But the key says filled = has dimples.

I recall that in some pedigrees, filled might mean affected, but here it's specified.

Let's look at question B: "What is the genotype of individual #3 and 4?"

If they are both open, and no dimples is recessive, then they would be dd, but then their child #10 has dimples, which would require her to be DD or Dd, but parents are dd, impossible.

Unless #10 is not their child, but the diagram shows she is.

Perhaps #3 and #4 are not the parents of #10? But in standard pedigree notation, they are.

I think I need to proceed with the only logical way: assume that for individuals with dimples, they must have at least one D, and for those without, dd, and resolve the contradictions by inferring that some parents must be heterozygous even if they show the recessive phenotype, but that violates dominance.

Perhaps for #3 and #4, since they have a child with dimples, they must be carriers, but if dimples is dominant, carriers would have dimples, but they don't.

I'm stuck.

Let's try to answer the questions as per the data, ignoring the genetic impossibility for now.

Question A: How many family members have dimples?

From the filled symbols: #1, #10, #12, #14 → 4 people.

Question B: Genotype of #3 and #4.

They are open, so no dimples, so if dimples is dominant, they are dd.

But then #10 can't have dimples.

Perhaps the problem has a typo, and #10 is open, but she's drawn filled.

Or perhaps #3 or #4 is filled.

Let's assume that #4 is filled, but user said open.

Another approach: perhaps "dimples" is recessive, and the problem statement is incorrect.

Let me test that.

Suppose dimples is recessive.

Then filled = has dimples = dd

Open = no dimples = D_

Then for #3 and #4: both open → no dimples → D_

Their child #10: filled → has dimples → dd

So both parents must be Dd (carriers).

That works.

Similarly, #8 and #9: both open → no dimples → D_

Their children: #12 filled (dd), #13 open (D_), #14 filled (dd)

So for #12 and #14 to be dd, both parents must be Dd.

#13 is open, so could be DD or Dd.

Also, #1: filled → dd (has dimples)

#2: open → no dimples → D_

Their children: #5,6,7,8 all open → no dimples → D_

Since #1 is dd, he gives d to all children.

Children are D_, so they must have gotten D from #2.

So #2 must be DD or Dd.

If #2 were DD, all children would be Dd → no dimples, good.

If #2 were Dd, children could be Dd or dd, but all are open (no dimples), so no dd, so #2 must be DD, or if Dd, by chance all got D, but unlikely, but possible.

But in this case, with dimples recessive, it works.

Moreover, the problem says "Dimples is dominant to no dimples", but perhaps it's a mistake, and it's recessive.

Because otherwise, the pedigree is impossible.

In many textbooks, sometimes the dominance is stated incorrectly, or the shading is switched.

Given that, and to make the pedigree work, I'll assume that "dimples" is recessive, despite the problem saying otherwise.

Perhaps "dimples" is the recessive trait.

Let me check the second problem for consistency.

In problem 2, it says: "The Eyebrow gene is a recessive trait. A person only has a unibrow if they have two recessive alleles."

And filled symbols have unibrow, so filled = recessive phenotype.

In problem 1, if filled = has dimples, and if dimples is recessive, then it matches.

But the problem explicitly says "Dimples is dominant to no dimples".

However, in the context, perhaps it's a common mistake, or perhaps for this worksheet, we should go with the pedigree logic.

Maybe "dimples" is dominant, but the filled symbols are those without dimples? But the key says filled = has dimples.

I think for the sake of completing the task, I'll assume that the trait is recessive, as it makes the pedigree work, and perhaps the problem has a typo.

So let's redefine:

Assume that having dimples is recessive (dd), and no dimples is dominant (D_).

Then:

Filled symbol = has dimples = dd

Open symbol = no dimples = D_ (DD or Dd)

Now, let's assign genotypes.

Generation I:

#1: filled male → has dimples → dd

#2: open female → no dimples → D_

#3: open male → no dimples → D_

#4: open female → no dimples → D_

Generation II:

#5: open male → no dimples → D_

#6: open female → no dimples → D_

#7: open male → no dimples → D_

#8: open female → no dimples → D_

#9: open male → no dimples → D_

#10: filled female → has dimples → dd

#11: open male → no dimples → D_

Generation III:

#12: filled male → has dimples → dd

#13: open female → no dimples → D_

#14: filled female → has dimples → dd

Now, family relationships.

First, #1 and #2 are parents of #5,6,7,8.

#1 is dd.

All children are open → no dimples → D_

Since #1 gives d to all children, and children are D_, they must have gotten D from #2.

So #2 must be DD or Dd.

If #2 were Dd, children could be Dd or dd, but all are D_ (no dimples), so no dd, so #2 must be DD, or if Dd, by chance all children got D, but to be safe, likely #2 is DD.

But let's see.

Children are all D_, and got d from #1, so they are all Dd.

So #2 must have given D to all, so #2 could be DD or Dd, but if Dd, probability of giving D is 50%, and all four children got D, which is possible but less likely. In genetics problems, we often assume the simplest, so perhaps #2 is DD.

But let's keep it as D_ for now.

Actually, since all children are Dd (because they got d from #1 and D from #2), so #2 must be able to give D, so #2 is D_ , and specifically, since she gave D to all, she could be DD or Dd, but we can't distinguish yet.

Now, #3 and #4 are parents of #9, #10, #11.

#10 is dd (has dimples).

So both parents must have given d to #10.

#3 and #4 are both open → no dimples → D_

So they must be Dd (carriers), because if either were DD, they couldn't give d.

So #3: Dd

#4: Dd

Then their children:

#9: open → no dimples → D_ → could be DD or Dd

#10: dd

#11: open → D_ → DD or Dd

Probability: 25% DD, 50% Dd, 25% dd, which matches since #10 is dd, others are not.

Now, #8 and #9 are parents of #12, #13, #14.

#12: dd

#14: dd

#13: open → D_

Both #12 and #14 are dd, so they got d from both parents.

So #8 and #9 must both be able to give d, so they must be Dd (since they are open, no dimples, so not dd).

So #8: Dd

#9: Dd

Then their children:

#12: dd

#13: D_ (could be DD or Dd)

#14: dd

Which is consistent.

Now, back to #8: she is child of #1 and #2.

#1 is dd.

#8 is Dd (as above).

Since #1 gives d, #8 got d from #1, and D from #2, so #2 must have given D to #8.

Similarly for other children.

So #2 must be D_ , and since she gave D to all her children (who are all Dd), she could be DD or Dd.

But if she were Dd, she could give d, but none of her children are dd (all are open, no dimples), so she must have given D to all, so likely she is DD, or if Dd, by chance.

In such problems, we often specify the genotype as precisely as possible.

For #2, since all her children are Dd (got d from #1, D from her), and she has no dimples, she could be DD or Dd, but to ensure all children are D_, she must be DD, because if she were Dd, there's a 50% chance per child to be dd, but here all are not dd, so probably she is DD.

But technically, she could be Dd, and by luck all children got D.

However, in standard pedagogy, we usually say she is DD if all offspring show the dominant trait when crossed with recessive.

Here, #1 is dd (recessive), #2 is D_, children are all D_ (specifically Dd), so #2 must be DD, because if she were Dd, half the children should be dd, but none are.

So #2: DD

Similarly, for #3 and #4, both Dd.

#8: Dd (child of #1 dd and #2 DD, so must be Dd)

#9: child of #3 Dd and #4 Dd, and he is open, so D_ , and since he has children with #8 who are dd, he must be Dd (because he gave d to #12 and #14).

Similarly, #8 is Dd.

Now, let's answer the questions.

Question A: How many family members have dimples?

Have dimples = filled symbols = dd = #1, #10, #12, #14 → 4 people.

Question B: What is the genotype of individual #3 and 4?

As above, both are Dd (since they have a child with dimples, dd, and they themselves do not have dimples, so must be carriers).

Question C: Can either individual #8 or 9 be homozygous?

Homozygous means same alleles, so for this trait, homozygous dominant DD or homozygous recessive dd.

#8: we said she is Dd, so heterozygous.

Could she be homozygous? If she were DD, then with #9, if #9 is Dd, children could be DD or Dd, all no dimples, but #12 and #14 have dimples (dd), so impossible. If #8 were dd, but she is open, no dimples, but if dimples is recessive, dd would have dimples, but she doesn't, so she can't be dd. So she must be Dd, not homozygous.

Similarly, #9: if he were DD, then with #8 Dd, children would be DD or Dd, all no dimples, but #12 and #14 have dimples, so impossible. If he were dd, he would have dimples, but he is open, no dimples, so can't be dd. So he must be Dd, not homozygous.

So neither can be homozygous.

Question D: Explain the family relationship that #12 has with #2.

#12 is child of #8 and #9.

#8 is child of #1 and #2.

So #2 is grandmother of #12.

Specifically, maternal grandmother, since #8 is female.

#2 is mother of #8, #8 is mother of #12, so #2 is maternal grandmother of #12.

Now, to confirm, let's list all genotypes.

Generation I:

#1: dd (has dimples)

#2: DD (no dimples) — assumed, since all children are Dd

#3: Dd (no dimples)

#4: Dd (no dimples)

Generation II:

#5: Dd (no dimples) — child of #1 dd and #2 DD

#6: Dd

#7: Dd

#8: Dd

#9: Dd (child of #3 Dd and #4 Dd, and he is no dimples, and must be Dd to have dd children)

#10: dd

#11: could be DD or Dd, but since parents are both Dd, and he is no dimples, probability 1/3 DD, 2/3 Dd, but we don't know, so perhaps leave as D_ , but for accuracy, since no information, we can say D_ , but in this case, for the questions, not needed.

Generation III:

#12: dd

#13: D_ (could be DD or Dd)

#14: dd

Now, for question C: can #8 or #9 be homozygous? As above, no, because if either were homozygous, they couldn't have children with dimples (dd) while themselves not having dimples.

Specifically, if #8 were DD, she couldn't give d, but #12 and #14 are dd, so must get d from her, contradiction.

If #8 were dd, she would have dimples, but she doesn't.

Same for #9.

So neither can be homozygous.

Family relationship: #12 is grandchild of #2, specifically through daughter #8.

So maternal grandson.

Now, to box the answers.

But earlier I assumed dimples is recessive, contrary to the problem statement.

Perhaps the problem intends dimples to be dominant, and there's a different interpretation.

Another possibility: perhaps "dimples" is dominant, but the filled symbols are those without dimples? But the key says filled = has dimples.

Or perhaps in the pedigree, the shading is for the recessive trait.

I recall that in some contexts, filled might mean affected by a disorder, but here it's dimples, which is not a disorder.

Perhaps for this worksheet, we should go with the dominant assumption and accept that #10 and #12,#14 are anomalies, but that doesn't help.

Let's try to force the dominant assumption.

Assume dimples is dominant (D), no dimples is recessive (d).

Filled = has dimples = D_

Open = no dimples = dd

Then:

#1: filled → D_

#2: open → dd

#3: open → dd

#4: open → dd

#5: open → dd

#6: open → dd

#7: open → dd

#8: open → dd

#9: open → dd

#10: filled → D_

#11: open → dd

#12: filled → D_

#13: open → dd

#14: filled → D_

Now, #1 and #2: #2 is dd, children #5,6,7,8 are all dd.

So #1 must have given d to all, so #1 must be Dd (because if DD, children would be Dd, have dimples, but they don't).

So #1: Dd

#2: dd

Children: all dd — good.

#3 and #4: both dd.

Children: #9 dd, #10 D_, #11 dd.

#10 is D_, but parents are both dd, so she must be dd, but she's not — contradiction.

Same for #8 and #9: both dd, children #12 D_, #13 dd, #14 D_ — impossible.

So still contradiction.

Therefore, the only way the pedigree makes sense is if dimples is recessive.

Perhaps the problem has a typo, and it's "no dimples is dominant", but it says "dimples is dominant".

Or perhaps "dimples" is the recessive trait.

I think for the sake of providing an answer, I'll go with the recessive assumption, as it resolves the issues.

So final answers:

A) 4 family members have dimples: #1, #10, #12, #14

B) Genotype of #3 and #4: both Dd (heterozygous)

C) No, neither #8 nor #9 can be homozygous. #8 must be Dd to have children with dimples (dd) while not having dimples herself. Similarly for #9.

D) #12 is the grandson of #2. Specifically, #2 is the mother of #8, and #8 is the mother of #12, so #2 is the maternal grandmother of #12.

Now, to write it nicely.

For the genotype, since we're using D for no dimples (dominant), d for dimples (recessive), but the problem uses D for dimples gene, with D dominant.

To match the problem's notation, even though we're assuming recessive, we should use their letters.

The problem says: "Dimples gene (D)", and "Dimples is dominant to no dimples".

But in our solution, we have dimples as recessive, so perhaps we should use d for dimples.

To avoid confusion, let's define:

Let D = allele for no dimples (dominant)

d = allele for dimples (recessive)

But the problem calls the gene "Dimples gene (D)", implying D is for dimples.

Perhaps in the answer, we can use the letters as per the problem, but state the assumption.

Since the problem likely has a typo, and to match the pedigree, I'll use:

Let D = dominant allele for no dimples

d = recessive allele for dimples

But the problem says "Dimples gene (D)", so perhaps D is the allele for dimples.

I think it's better to use the problem's notation and assume that "dimples" is recessive, so the allele for dimples is d, and for no dimples is D.

But the problem says "Dimples gene (D)", which might mean D is the allele for dimples.

This is messy.

Perhaps in the answer, for genotype, we can write it as per standard.

For individual #3 and #4, if dimples is recessive, they are heterozygous, so if D is the dominant allele for no dimples, then they are Dd.

But the problem might expect D for dimples.

Let's look at the second problem for clue.

In problem 2, it says: "Eyebrow gene (E)", and "recessive trait", and filled = has unibrow = recessive, so ee.

So for consistency, in problem 1, if filled = has dimples, and if it's recessive, then dd.

And the gene is called "Dimples gene (D)", but D might be the name, not the allele.

In genetics, the gene is named, and alleles are denoted by letters.

So "Dimples gene (D)" might mean the gene is D, and alleles are D and d, with D dominant for dimples.

But in that case, our earlier contradiction remains.

Perhaps for this worksheet, we should proceed with the dominant assumption and say that #3 and #4 are dd, and #10 is Dd, but that requires a mutation or something.

I think the best is to box the answers as per the recessive assumption, as it's the only logical way.

So for Final Answer:

A) 4

B) Both are heterozygous (Dd, where D is no dimples, d is dimples) — but to match problem, perhaps say "both are carriers" or "both have one dominant and one recessive allele".

Since the problem asks for genotype, and in the context, for #3 and #4, if they have no dimples but have a child with dimples, and dimples is dominant, it's impossible, so perhaps the answer is that they are both dd, but then #10 can't have dimples.

I recall that in some cases, if the trait is dominant, and parents are unaffected, children can't be affected, so perhaps #10 is not their biological child, but that's not indicated.

Perhaps #4 is filled, but user said open.

I think I have to go with the recessive assumption.

So for the answer:

A) 4

B) #3: Dd, #4: Dd (where D is the allele for no dimples, d for dimples) — but to match the problem's notation, perhaps use d for dimples allele.

Let's define: let d = allele for dimples (recessive), D = allele for no dimples (dominant).

Then genotype of #3 and #4 is Dd.

C) No, neither can be homozygous. #8 must be Dd to have children with dimples (dd) while not having dimples. Similarly for #9.

D) #12 is the grandson of #2. #2 is the mother of #8, and #8 is the mother of #12, so #2 is the maternal grandmother of #12.

Now for the boxed answer.

Perhaps in the problem, "Dimples gene (D)" means the gene is D, and the dominant allele is D for dimples, but in that case, we can't resolve, so for the sake of time, I'll provide the answer as per recessive.

So Final Answer:

A) 4

B) Both are heterozygous (genotype Dd, where D is the dominant allele for no dimples, d is the recessive allele for dimples)

But to match the problem's lettering, perhaps say "both have genotype Dd" with D being the allele for no dimples.

Since the problem might expect D for dimples, but then