In humans, attached earlobes are a dominant feature over free earlobes while hypertrichosis of the ear is a holandric ($\mathrm{Y}$-linked) feature. A man with attached earlobes and extensive hair on pinna married a woman having free earlobes. The couple had one son with attached earlobes and hairy pinna, another son with free earlobes and hairy pinna and two daughters with attached earlobes. One of the daughters married a man with free earlobes and sparse hair on pinna. They had two sons. What would be the characteristics of their pinnae?

Refer to the given statements.

(i) Incomplete or mosaic inheritance is an example of the pre-Mendelian concept of blending inheritance.

(ii) Test cross is a special type of back cross.

(iii) Chromosomal aberrations are commonly observed in cancer cells.

(iv) Thalassaemia is a Mendelian disorder.

Which of the above statements are correct?

Study the given pedigree chart for sickle-cell anaemia and select the most appropriate option for the genotypes.

Read the following statements and state true (T) and false (F):

A. Mendel experimented on $14$ true breeding pea plant varieties.

B. Mendel conducted hybridization experiments on garden pea from $1856$ to $1863.$

C. All genes for seven characters studied by Mendel were located on same chromosomes.

D. Mendel’s work on inheritance of characters remain unrecognized for $16$ years after his death.