MEDICAL BIOLOGY, ANATOMY, HUMAN PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedonyuk 2010

BIOLOGY

CHAPTER 1. BIOLOGICAL FOUNDATIONS OF HUMAN VITAL ACTIVITY

1.4. ONTOGENETIC LEVEL OF LIFE ORGANIZATION

1.4.2. Basics of Human Genetics

Mendelian Traits in Humans, Monogenic Diseases, Monogenic Inheritance

Traits that are inherited According to the patterns established by G. Mendel are called Mendelian traits. Some Mendelian human traits are listed in Table 1.6. Their total number exceeds 2,300.

Class="center">Table 1.6

Mendelian traits in humans

Dominant

Recessive

Normal

Brown eyes

Blue eyes

Dark Hair

Light hair

Slanted eyes

Straight eyes

Nose with a hump

Straight nose

Wide gap between central incisors

Narrow gap between central incisors or absence thereof

Large, protruding Teeth

Normal tooth shape and position

Dimples on Cheeks

Absence of dimples

White forelock of hair

Even hair pigmentation

Presence of freckles

Absence of freckles

Unattached earlobe

Attached earlobe

Full Lips

Thin lips

Right-handedness

Left-handedness

Rh-positive Blood

Rh-negative blood

Ability to roll the Tongue into a tube

Inability to roll the tongue into a tube

Ability to taste PTC

Inability to taste PTC

(phenylthiocarbamide)


Pathological

Achondroplastic dwarfism

Normal skeletal development

Polydactyly (6 or more fingers/toes)

Normal number of fingers/toes

Brachydactyly (short fingers)

Normal finger Structure

Syndactyly (webbed fingers)

Normal finger structure

Normal blood clotting

Hemophilia (blood clotting disorder)

Colonic polyposis

Absence of polyposis

Normal Color Vision

Color blindness (color vision deficiency)

Presence of Skin and hair pigments

Albinism (absence of pigments)

Normal phenylalanine METABOLISM

Phenylketonuria (inability to metabolize phenylalanine)

Normal lactose metabolism

Galactosemia (inability to metabolize lactose)

Normal Fructose Metabolism

Fructosuria

Normal Hemoglobin molecule structure

Sickle Cell anemia

All Mendelian traits are discrete and controlled monogenically, i.e., by a single Gene (monogenic inheritance). Monogenic diseases, which are also controlled by a single gene, belong to Mendelian traits. The following types of monogenic inheritance are distinguished: autosomal dominant, autosomal recessive, X-linked (dominant and recessive), and Y-linked. The traits of these inheritance patterns are identified using the genealogical method by compiling and analyzing pedigrees.



Last update: 08/08/2026

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