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Science of Genetics

GS Paper 3

Syllabus: Science and Technology


Source: The Hindu

Context: 200 years of the father of genetics, Gregor Mendel.

Genetics: Genetics is the study of genes, genetic variation, and heredity in organisms.

It was  first experimentally established by Gregor Mendel (a monk) (1822 to 1884)

His contributions to Science:

  • Principles of Inheritance: By experimenting with pea plant breeding, Mendel developed three principles of inheritance that described the transmission of genetic traits, before anyone knew genes existed.
    • To this day, scientists use Mendel’s principles to explain the most basic phenomena of inheritance.
  • Foundation of biology: Mendel’s theory, together with the evolutionary theory propounded by Charles Darwin, laid the foundations of biology.
  • Cure for many human diseases: Assisted clinicians in human diseaseresearch
    • For example, within just a couple of years of the rediscovery of Mendel’s work, Archibald Garrod applied Mendel’s principles to his study of alkaptonuria (discolouration of the skin)
    • Science of genomics and gene editing has its root in the work of Mendel.
  • First to apply maths to biology: He may have been the first botanist who seriously applied mathematics to biology, unlike Charles Darwin, who was judged by observation rather than by calculation.
  • He was the one who coined the terms dominant and recessive to describe these traits, which are used even today.


Insta Links

Towards Genomics Revolution


Practice Questions

In the context of hereditary diseases, consider the following statements: (UPSC 2021)

    1. Passing on mitochondrial diseases from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg.
    2. A child inherits mitochondrial diseases entirely from the mother and not from the father.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: C

Mitochondrial replacement therapy (MRT) is a form of reproductive in-vitro fertilization (IVF) which works on the principle of replacing a women’s mitochondrial DNA (mt-DNA) with the donor’s healthy one.

In the offspring, the mitochondrial genes are inherited from the mother. Thus, a father with a mitochondrial gene defect cannot transmit the disease to his offspring.

Fig: mitochondrial transfer (making of three parents babies)

Bollgard I and Bollgard II technologies are mentioned in the context of (UPSC 2021)

(a) clonal propagation of crop plants.

(b) developing genetically modified crop plants.

(c) production of plant growth substances.

(d) production of biofertilizers.

Answer: B

Bollgard I Bt cotton (single-gene technology) is India’s first biotech crop technology approved for commercialization in India in 2002, followed by Bollgard II – double-gene technology in mid-2006, by the Genetic Engineering Approval Committee (GEAC), the Indian regulatory body for biotech crops.