CONCEPTOS BÁSICOS DE GENÉTICA | RM

Understanding Genetics Basics

In this section, the basics of genetics are discussed, including genes, alleles, genotypes, phenotypes, chromosomes, and genetic variability.

Genes and Alleles

• Genes are the minimum unit of genetic information composed of DNA. Each gene has a specific function.

• Alleles are different expressions of a gene. For example, eye color alleles can be black, blue, green, or brown.

• Homozygotes have identical alleles for a trait while heterozygotes have different alleles.

Dominance and Genotype

• Dominance determines which allele is expressed over the other.

• Co-dominance occurs when both alleles are expressed simultaneously.

• Dominant alleles always manifest while recessive ones need another recessive allele to show.

Phenotype and Chromosomes

• Genotype represents all an individual's genes while phenotype is the observable characteristics influenced by genotype and environment.

• Chromosomes carry genetic information with autosomes (non-sex chromosomes) and sex chromosomes (determining gender).

• Chromosomes consist of chromatin parts like telomeres and centromeres.

Genetic Variability

• Variability arises from different genotypes in a population due to sexual reproduction and chromosome crossover during meiosis.

• Mutations contribute to genetic variability through spontaneous changes in DNA sequences.

Detailed Genetic Mutations Discussion

The discussion delves into aneuploidies, such as monosomies and trisomies, like Turner syndrome and Down syndrome. It distinguishes between germline and somatic mutations, highlighting their impact on genetic variability and heritability.

Aneuploidies and Genetic Mutations

• Aneuploidies lead to conditions like Turner syndrome (X chromosome monosomy) and Klinefelter syndrome (XXY trisomy).

• Two types of mutations exist: germline and somatic. Germline mutations are inherited while somatic mutations occur in body cells.

Impact of Somatic Mutations

• Somatic cell mutations do not affect offspring as they do not impact the germline, hence not contributing to genetic variability.

• However, if a mutation occurs in a sex cell, it affects the entire genome when combined with another individual's sex cells, potentially altering the offspring's genetic makeup.