Question

1. complete the table below for each type of inheritance pattern.

	autosomal dominant	autosomal recessive	sex - linked dominant	sex - linked recessive

|key|d =
d = |d =
d = |h =
h = |h =
h = |
|genotypes and phenotypes|dd =
dd =
dd = |dd =
dd =
dd = |x^hx^h =
x^hx^h =
x^hx^h =
x^hy =
x^hy = |x^hx^h =
x^hx^h =
x^hx^h =
x^hy =
x^hy = |

Explanation:

Step1: Define alleles for autosomal inheritance

In autosomal dominant inheritance, $D$ represents the dominant allele and $d$ represents the recessive allele. In autosomal recessive inheritance, the same $D$ is the dominant allele and $d$ is the recessive allele.

Step2: Determine genotypes and phenotypes for autosomal dominant

• $DD$: Homo - zygous dominant genotype, shows dominant phenotype.
• $Dd$: Heterozygous genotype, shows dominant phenotype.
• $dd$: Homo - zygous recessive genotype, shows recessive phenotype.

Step3: Determine genotypes and phenotypes for autosomal recessive

• $DD$: Homo - zygous dominant genotype, shows dominant phenotype.
• $Dd$: Heterozygous genotype, shows dominant phenotype (carrier in terms of recessive trait).
• $dd$: Homo - zygous recessive genotype, shows recessive phenotype.

Step4: Define alleles for sex - linked inheritance

In sex - linked inheritance, $H$ is the dominant allele and $h$ is the recessive allele on the X - chromosome.

Step5: Determine genotypes and phenotypes for sex - linked dominant

• $X^{H}X^{H}$: Homo - zygous dominant female genotype, shows dominant phenotype.
• $X^{H}X^{h}$: Heterozygous female genotype, shows dominant phenotype.
• $X^{h}X^{h}$: Homo - zygous recessive female genotype, shows recessive phenotype.
• $X^{H}Y$: Hemizygous dominant male genotype, shows dominant phenotype.
• $X^{h}Y$: Hemizygous recessive male genotype, shows recessive phenotype.

Step6: Determine genotypes and phenotypes for sex - linked recessive

• $X^{H}X^{H}$: Homo - zygous dominant female genotype, shows dominant phenotype.
• $X^{H}X^{h}$: Heterozygous female genotype, shows dominant phenotype (carrier in terms of recessive trait).
• $X^{h}X^{h}$: Homo - zygous recessive female genotype, shows recessive phenotype.
• $X^{H}Y$: Hemizygous dominant male genotype, shows dominant phenotype.
• $X^{h}Y$: Hemizygous recessive male genotype, shows recessive phenotype.

	Autosomal Dominant	Autosomal Recessive	Sex - linked Dominant	Sex - linked Recessive
Genotypes and Phenotypes	$DD$: Dominant phenotype <br> $Dd$: Dominant phenotype <br> $dd$: Recessive phenotype	$DD$: Dominant phenotype <br> $Dd$: Dominant phenotype (carrier) <br> $dd$: Recessive phenotype	$X^{H}X^{H}$: Dominant phenotype <br> $X^{H}X^{h}$: Dominant phenotype <br> $X^{h}X^{h}$: Recessive phenotype <br> $X^{H}Y$: Dominant phenotype <br> $X^{h}Y$: Recessive phenotype	$X^{H}X^{H}$: Dominant phenotype <br> $X^{H}X^{h}$: Dominant phenotype (carrier) <br> $X^{h}X^{h}$: Recessive phenotype <br> $X^{H}Y$: Dominant phenotype <br> $X^{h}Y$: Recessive phenotype

Answer:

Step1: Define alleles for autosomal inheritance

In autosomal dominant inheritance, $D$ represents the dominant allele and $d$ represents the recessive allele. In autosomal recessive inheritance, the same $D$ is the dominant allele and $d$ is the recessive allele.

Step2: Determine genotypes and phenotypes for autosomal dominant

• $DD$: Homo - zygous dominant genotype, shows dominant phenotype.
• $Dd$: Heterozygous genotype, shows dominant phenotype.
• $dd$: Homo - zygous recessive genotype, shows recessive phenotype.

Step3: Determine genotypes and phenotypes for autosomal recessive

• $DD$: Homo - zygous dominant genotype, shows dominant phenotype.
• $Dd$: Heterozygous genotype, shows dominant phenotype (carrier in terms of recessive trait).
• $dd$: Homo - zygous recessive genotype, shows recessive phenotype.

Step4: Define alleles for sex - linked inheritance

In sex - linked inheritance, $H$ is the dominant allele and $h$ is the recessive allele on the X - chromosome.

Step5: Determine genotypes and phenotypes for sex - linked dominant

• $X^{H}X^{H}$: Homo - zygous dominant female genotype, shows dominant phenotype.
• $X^{H}X^{h}$: Heterozygous female genotype, shows dominant phenotype.
• $X^{h}X^{h}$: Homo - zygous recessive female genotype, shows recessive phenotype.
• $X^{H}Y$: Hemizygous dominant male genotype, shows dominant phenotype.
• $X^{h}Y$: Hemizygous recessive male genotype, shows recessive phenotype.

Step6: Determine genotypes and phenotypes for sex - linked recessive

• $X^{H}X^{H}$: Homo - zygous dominant female genotype, shows dominant phenotype.
• $X^{H}X^{h}$: Heterozygous female genotype, shows dominant phenotype (carrier in terms of recessive trait).
• $X^{h}X^{h}$: Homo - zygous recessive female genotype, shows recessive phenotype.
• $X^{H}Y$: Hemizygous dominant male genotype, shows dominant phenotype.
• $X^{h}Y$: Hemizygous recessive male genotype, shows recessive phenotype.

	Autosomal Dominant	Autosomal Recessive	Sex - linked Dominant	Sex - linked Recessive
Genotypes and Phenotypes	$DD$: Dominant phenotype <br> $Dd$: Dominant phenotype <br> $dd$: Recessive phenotype	$DD$: Dominant phenotype <br> $Dd$: Dominant phenotype (carrier) <br> $dd$: Recessive phenotype	$X^{H}X^{H}$: Dominant phenotype <br> $X^{H}X^{h}$: Dominant phenotype <br> $X^{h}X^{h}$: Recessive phenotype <br> $X^{H}Y$: Dominant phenotype <br> $X^{h}Y$: Recessive phenotype	$X^{H}X^{H}$: Dominant phenotype <br> $X^{H}X^{h}$: Dominant phenotype (carrier) <br> $X^{h}X^{h}$: Recessive phenotype <br> $X^{H}Y$: Dominant phenotype <br> $X^{h}Y$: Recessive phenotype