Understanding Chromosomes, Genetics, and Environmental Factors

Karyotype: Chromosome Visualization

A karyotype is a visual representation of the chromosomes within a single cell, where the number of chromosomes, their arrangement, size, and structure can be observed.

Genetic Differences

Genetic characteristics are inherited and they make up an individual's genotype. Beneficial genetic capabilities can be enhanced by living a healthy lifestyle: adequate nutrition, and healthy habits (exercise, relaxation).

Environmental Factors

These are the climates, nutrition, and many other factors that have an effect on our lives. The effects they have on a phenotype are not transmissible.

Discontinuous Characteristics

• Hairline: Straight or V-shaped
• Tongue: Ability to roll it into a U-shape or not
• Ear lobe: Attached or detached
• Hair: Curly or straight
• Eyelashes: Long or short
• Freckles: Presence or absence of freckles

Genetic Disorders

Single Gene Disorders

They only affect one gene, modifying the sequence of nitrogenous bases.

Chromosomal Disorders

They only affect fragments of chromosomes, which can be deleted, duplicated, inverted, or translocated.

Genomic Disorders

They affect whole chromosomes, so the total number of them in the organism is modified.

Sex-Linked Disorders

Sex-linked disorders have the gene in one X chromosome, in which case the women will be healthy but carry the illness, or have the gene in both X chromosomes, in which case they will suffer from the illness.

Haemophilia and Color Blindness

Haemophilia is a disease that is characterized by the absence of some proteins that help coagulate blood. If a small blood vessel breaks, even a small one, it can lead to several hemorrhages. Color blindness follows the same heredity pattern as haemophilia. A color-blind individual has difficulties differentiating certain colors due to a disorder in the retina's cells.

Ichthyosis

Ichthyosis is a thickening and scaling of the skin that is also due to a gene located in the differential segment of chromosome X.

Genomic Disorders

Monosomy

When a pair of homologous chromosomes is missing. The absence of genetic information is lethal, so monosomy could not survive. Their chromosomes would be 2n-2.

Trisomy

When there is an extra chromosome in a pair of homologous chromosomes, their chromosomes would be 2n+1.