In which of the following studies the concept of critical period originated?

Many of our physical characteristics, like, height, bone structure, hair and eye colour are

A. Inherited

B. Non inherited

C. Secondary qualities

D. None of the above

Twins developed from different egg cells are known as

A. Dizygotic

B. Monozygotic

C. Zygotic

D. None of the above

Delinquency is often associated with

A. Low parental support

B. Inappropriate discipline

C. Family discord

D. All of the above

A normal female has two similar appearing chromosomes in pair 23, called

A. X chromosomes

B. Y chromosomes

C. A chromosomes

D. None of the above