Which of the following statements is true?
1
The term 'Genetics’ was coined by J. D. Watson in 1906.
2
In human beings, there are 46 chromosomes. Of these, 42 (21 pairs) are autosomes and 4 (2 pairs) are sex chromosomes.
3
Mendel was the first scientist to visualise a gene as an inheritance in 1886.
4
A DNA molecule is made up of two long polynucleotide strands forming a double helical structure (double helix) just like a spiral staircase.