Track 17: Genetics

Meaning: Genetics is the branch of biology that studies genes, heredity, and genetic variation in living organisms. It focuses on how traits and characteristics are passed down from parents to offspring through DNA, the molecule that carries genetic information. Genetics plays a crucial role in understanding how organisms develop, function, and evolve over time.

Key Concepts in Genetics

1. Genes and DNA:

   • Genes are segments of DNA that carry instructions for making proteins, which determine an organism’s traits.
   • DNA (Deoxyribonucleic Acid) is the genetic material found in the cells of all living organisms. It consists of two long strands forming a double helix, made up of nucleotides that encode genetic information.

2. Chromosomes:

   • Humans have 46 chromosomes, grouped into 23 pairs. One set comes from the mother, and the other from the father. These chromosomes contain the genes that determine inherited traits.

3. Inheritance:

   • Heredity is the process by which parents pass on their genetic material to their offspring. Traits are inherited through dominant and recessive alleles (variants of a gene).
   • Mendelian Inheritance: Based on the work of Gregor Mendel, inheritance follows predictable patterns, such as dominant and recessive traits.

4. Mutations:

   • A mutation is a change in the DNA sequence. Mutations can be harmless, beneficial, or harmful, and they can be inherited or occur spontaneously.
   • Mutations can lead to genetic disorders if they occur in certain genes (e.g., cystic fibrosis, sickle cell anemia).

5. Genetic Variation:

   • Genetic variation refers to the differences in DNA sequences among individuals within a population. It is the basis for evolution and diversity in species.

6. Genotype and Phenotype:

   • Genotype refers to an individual’s genetic makeup— the specific alleles they carry.
   • Phenotype is the observable traits or characteristics of an individual, influenced by their genotype and environmental factors (e.g., eye color, height).