Mendelian Genetics for NEET

Genetics is an important part of the assessment for the National Eligibility Entrance Test (NEET)conducted in India for admission in Medical colleges of India. It is part of the Biology syllabus and the weightage of the topic is approx. 6 – 7%. The course includes the following topics:

a. Introduction to Mendel Experiments

b. Monohybrid Experiments

c. Dihybrid Experiments

d. Types of Dominance

e. Multiple Alleles

f. Lethal gene and Pleiotropic gene

g. Interaction of Gene

h. Linkage and gene mapping

The course consists of a detailed lecture on each topic with a focus on conceptual clarity. In the first section of Introduction to Mendelian genetics, the historical aspects of the mendelian experiment are discussed. It is followed by the description of the experiment leading to monohybrid and dihybrid inheritance, their observations and statistical analysis leading to monohybrid and dihybrid phenotypic and genotypic ratios. Some problem of hybridization has also been discussed in the chapter on dihybrid inheritance which is mostly asked in competitive examination.

In the second section, the exception to Mendelian inheritance is discussed. How mendelian laws/hypotheses of inheritance fail to operate in different cases are elaborated. How and why does the typical law of dominance fail to operate in a similar manner in the case of incomplete dominance and co-dominance. Similarly, multiple alleles are a deviation from the mendelian concept of two alleles for a gene, however, it follows the laws of dominance and segregation.