The basic unit of heredity is

Heredity refers to the features and characteristics of people that are passed down from generation to generation. The study of such transmittable features is known as genetics.

🛑Important Points:
 A gene is the basic physical and functional unit of heredity. A gene is a segment of DNA that carries information from parents to children and determines the heredity characters in the offspring. 
A gene is a basic unit of heredity. Each gene has a specific code, and these codes are used to develop the characteristics of a person.
Genes are a small stretch of DNA present on chromosomes.
Genes code for functional proteins.
Genes are inherited from one generation to another.
The human genome consists of around 30,000 genes.
Dystrophin is the largest known gene present in humans and it consists of around 2.4 million bases.

🔴Additional Information:
Chromosome:-  Chromosomes carry genetic information in the form of genes. 
Zygote:- A zygote is a single-celled organism resulting from a fertilized egg.