In a gene pool, along with beneficial mutations those mutations also exists which are damaging to an individual. It has been found that these mutations are irreversible because

$I.$ they have survival value

$II.$ they are acquired

$III.$ they are recessive and carried by heterozygous individuals only

$IV.$ they show genetic drift

Choose the incorrect option for given statement

$A$ : One drum stick per nucleus is present in the neutrophil of normal female.
$R$ : It is absent in the neutrophil of male

How many true breeding pea plant varieties did Mendel select as pairs, which were similar except in one character with contrasting tralts$?$

Mark the correct match

You are required to draw blood from a patient and to keep it in a test tube for analysis of blood corpuscles and plasma. You are also provided with the following four types of test tubes. Which of them will you not use for the purpose.