Inheritance

Fundamentals of Genetics

Genetics is field of biology focussing on the study of genes, inheritance and variation in living organisms.
Inheritance refers to the process by which genetic information is transmitted from one generation to the next.
A gene is a sequence of DNA that codes for a specific protein, influencing an individual’s traits.

Types of Inheritance

Mendelian Inheritance: Based on the principles established by Gregor Mendel, where alleles segregate independently during gamete formation, and traits are passed on from parents to offspring in predictable ways.
Non-Mendelian Inheritance: Includes mechanisms such as codominance, incomplete dominance, multiple alleles and polygenic inheritance.

Genetic Diversity

Genetic diversity is crucial for the survival and adaptation of a species. It is a result of gene variability, mutation and sexual reproduction.
Allelic variation is the basis for most genetic diversity – different versions of the same gene, known as alleles, can lead to different traits in individuals.
Gene flow and genetic drift can also contribute to genetic diversity.

Concepts in Genetic Inheritance

The Law of Segregation states that during gamete formation, pairs of allele for each trait segregate (separate) so that half the gametes carry one allele, and half carry the other.
The Law of Independent Assortment states that genes for different traits assort independently of one another during gamete formation.

Role of Chromosomes and DNA

Chromosomes carry genes, which are made of DNA. Every human cell, except for sperm and egg cells, contains 46 chromosomes arranged in 23 pairs.
Homologous chromosomes are a pair of chromosomes, one from each parent, that are similar in shape and size.
In humans, one pair out of the 23 is a pair of sex chromosomes which determine the sex of the individual.

Genetic Disorders and Mutations

Ingenuity can lead to genetic disorders when there are alterations or mutations in the DNA sequence. Common genetic disorders include Down Syndrome, Cystic Fibrosis and Haemophilia.
Mutation is the change in the DNA sequence that changes the structure and function of the protein. Mutations can be spontaneous or induced.

Application of Inheritance

Understanding genetic inheritance allows for the development of predictive genetics and advances in medical research through genetic testing and screening.
It also aids in our understanding of evolution, as inheritance is the mechanism that leads to variation in a population.

Revision summary: Inheritance is a key part of continuous life. It encompasses many aspects from the basics and types of inheritance, genetic diversity and concepts in genetic inheritance to the role of chromosomes and DNA, genetic disorders and the applications of inheritance in real life. Understanding and remembering these concepts are imperative for a solid understanding of biology.