Using the provided pedigree chart and key, determine the number of family members with dimples and the…

Question

Using the provided pedigree chart and key, determine the number of family members with dimples and the genotype of individual 3.

ScanSolve AI Tutor · Accepted Answer

First, let's establish the alleles based on the key:

Unshaded (have dimples): Dominant allele (let's use $D$ )
Shaded (no dimples): Recessive allele (let's use $d$ ) Therefore, individuals with dimples have genotype $DD$ or $Dd$ . Individuals with no dimples have genotype $dd$ .

3.1
To find how many family members have dimples, we count all the unshaded individuals in the pedigree chart.
Unshaded individuals are: 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13.
Counting these individuals: 11 family members have dimples.

\boxed{\text{11}}

3.2

a) Step 1: Identify individual 3. Individual 3 is an unshaded square, meaning he has dimples. His genotype is either $DD$ or $Dd$ .

Observe his offspring.
Individual 10 is a shaded circle, meaning she has no dimples ( $dd$ ).
For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.
Since individual 3 has dimples but carries a $d$ allele, his genotype must be heterozygous.
a) The genotype of individual 3 is:
$\boxed{Dd}$
b) Step 1: Identify individual 4. Individual 4 is an unshaded circle, meaning she has dimples. Her genotype is either $DD$ or $Dd$ .
Observe her offspring.
As determined in 3.2a, individual 10 has no dimples ( $dd$ ).
For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.
Since individual 4 has dimples but carries a $d$ allele, her genotype must be heterozygous.
b) The genotype of individual 4 is:
$\boxed{Dd}$
3.3

a) Step 1: Identify individual 2. Individual 2 is an unshaded circle, meaning she has dimples. Her genotype is either $DD$ or $Dd$ .
Individual 2 mates with individual 1, who is a shaded square, meaning he has no dimples ( $dd$ ).
They have four children
individuals 5, 6, 7, and 8. All four children are unshaded, meaning they all have dimples ( $D\_$ ).
If individual 2 were heterozygous ( $Dd$ ), a cross with individual 1 ( $dd$ ) would result in $50\%$ of offspring having no dimples ( $dd$ ).
Since none of their four children have no dimples, it is highly probable that individual 2 is homozygous dominant.

a) Individual 2 is:
$\boxed{\text{Homozygous}}$
b) Step 1: Identify individual 9. Individual 9 is an unshaded square, meaning he has dimples. His genotype is either $DD$ or $Dd$ .
Individual 9 has a child, individual 12, who is a shaded square, meaning he has no dimples ( $dd$ ).
For individual 12 to have genotype $dd$ , he must have inherited one $d$ allele from individual 9 and one $d$ allele from individual 8.
Since individual 9 has dimples but carries a $d$ allele, his genotype must be heterozygous.
b) Individual 9 is:
$\boxed{\text{Heterozygous}}$
3.4
Identify individual 2.
Identify individual 8.
Individual 8 is the daughter of individual 2.
Identify individual 12.
Individual 12 is the son of individual 8.
Therefore, individual 2 is the mother of individual 8, who is the mother of individual 12.
The family relationship between individual 12 and individual 2 is:
$\boxed{\text{Maternal grandmother}}$

Using the provided pedigree chart and key, determine the number of family members with dimples and the genotype of individual 3.

Step-by-step solution

Observe his offspring.

For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.

Since individual 3 has dimples but carries a $d$ allele, his genotype must be heterozygous.

Observe her offspring.

For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.

Since individual 4 has dimples but carries a $d$ allele, her genotype must be heterozygous.

Individual 2 mates with individual 1, who is a shaded square, meaning he has no dimples ( $dd$ ).

They have four children

If individual 2 were heterozygous ( $Dd$ ), a cross with individual 1 ( $dd$ ) would result in $50\%$ of offspring having no dimples ( $dd$ ).

Individual 9 has a child, individual 12, who is a shaded square, meaning he has no dimples ( $dd$ ).

For individual 12 to have genotype $dd$ , he must have inherited one $d$ allele from individual 9 and one $d$ allele from individual 8.

Since individual 9 has dimples but carries a $d$ allele, his genotype must be heterozygous.

Identify individual 2.

Identify individual 8.

Identify individual 12.

Therefore, individual 2 is the mother of individual 8, who is the mother of individual 12.

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More Biology Questions

Using the provided pedigree chart and key, determine the number of family members with dimples and the genotype of individual 3.

Step-by-step solution

Observe his offspring.

For individual 10 to have genotype dddddd, she must have inherited one ddd allele from individual 3 and one ddd allele from individual 4.

Since individual 3 has dimples but carries a ddd allele, his genotype must be heterozygous.

Observe her offspring.

For individual 10 to have genotype dddddd, she must have inherited one ddd allele from individual 3 and one ddd allele from individual 4.

Since individual 4 has dimples but carries a ddd allele, her genotype must be heterozygous.

Individual 2 mates with individual 1, who is a shaded square, meaning he has no dimples (dddddd).

They have four children

If individual 2 were heterozygous (DdDdDd), a cross with individual 1 (dddddd) would result in 50%50\%50% of offspring having no dimples (dddddd).

Individual 9 has a child, individual 12, who is a shaded square, meaning he has no dimples (dddddd).

For individual 12 to have genotype dddddd, he must have inherited one ddd allele from individual 9 and one ddd allele from individual 8.

Since individual 9 has dimples but carries a ddd allele, his genotype must be heterozygous.

Identify individual 2.

Identify individual 8.

Identify individual 12.

Therefore, individual 2 is the mother of individual 8, who is the mother of individual 12.

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More Biology Questions

For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.

Since individual 3 has dimples but carries a $d$ allele, his genotype must be heterozygous.

For individual 10 to have genotype $dd$ , she must have inherited one $d$ allele from individual 3 and one $d$ allele from individual 4.

Since individual 4 has dimples but carries a $d$ allele, her genotype must be heterozygous.

Individual 2 mates with individual 1, who is a shaded square, meaning he has no dimples ( $dd$ ).

If individual 2 were heterozygous ( $Dd$ ), a cross with individual 1 ( $dd$ ) would result in $50\%$ of offspring having no dimples ( $dd$ ).

Individual 9 has a child, individual 12, who is a shaded square, meaning he has no dimples ( $dd$ ).

For individual 12 to have genotype $dd$ , he must have inherited one $d$ allele from individual 9 and one $d$ allele from individual 8.

Since individual 9 has dimples but carries a $d$ allele, his genotype must be heterozygous.