Dominant and Recessive Traits

There are two types of genes for each trait: Dominant, and Recessive. The combination determines the trait to be expressed

At the time of conception, sperm cell fuses with the ovum to create a new cell called Zygot with 46 (23 pairs) chromosomes. On each pair of Chromosomes, there are two genes that determine the inherited trait. This gene pair is called allele. If the two pair of allele are identical (one pair from each parent), the off spring will express that trait.

Normally, there are two types of genes for each trait: Dominant, and Recessive. Dominant genes when paired with recessive gene determines the trait to be expressed. Recessive gene is not expressed when paired with dominant gene. Recessive genes are only expressed when paired with another recessive gene.

Twenty two pair of Chromosomes look alike and are called autosomes. The twenty-third pair is different, two X-chromosomes for female, one X- and one Y- chromosome for a male. Therefore, this is called sex linked chromosomes.

Genes associated with dominant traits have more complete information than the recessive traits.

The Dominate/ Recessive is a comparative concept as well, which means that brown eye color is dominant trait when compared to grey, green, hazel, or blue eye colors.

Trait (Autosomes)	Dominant Trait	Recessive Trait
Eye color	brown eyes	grey, green, hazel, blue eyes
Vision	farsightedness normal vision normal vision normal vision	normal vision nearsightedness night blindness color blindness*
Hair	dark hair non-red hair curly hair widow's peak	blonde, light, red hair red hair straight hair normal hairline
Facial features	dimples unattached earlobes freckles broad lips	no dimples attached earlobes no freckles thin lips
Appendages	extra digits fused digits short digits fingers lack 1 joint limb dwarfing clubbed thumb double-jointedness	normal number normal digits normal digits normal joints normal proportion normal thumb normal joints
Miscellaneuous	immunity to poison ivy normal pigmented skin normal hearing normal hearing and speaking normal- no PKU	susceptibility to poison ivy albinism congenital deafness deaf mutism phenylketonuria (PKU)
Gender Linked Traits	Dominant Trait	Recessive Trait
Blood	normal blood clotting	hemophilia*
Hair	full head of hair	Male Pattern baldness

Dominant and Recessive Traits

Trait (Autosomes)

Dominant Trait

Recessive Trait

Gender Linked Traits

Dominant Trait