Which of the following statements is incorrect ?
$(i)$ Bamboo species flower only once in their life time, generally after $50-100$ years and produce large number of fruits and die.
$(ii)$ In animals, the juvenile phase is followed by morphological and physiological changes prior to active reproductive behaviour.
$(iii)$ The reproductive phase is of same duration in all organisms.
$(iv)$ Juvenile phase is the period of growth between the birth of an individual till it reaches reproductive maturity.

What is seen in zygote during embryogenesis ?

Which is not bisexual animal ?

Which of the following statements are correct regarding female reproductive cycle?

$A$. In non-primate mammals cyclical changes during reproduction are called oestrus cycle.

$B$. First menstrual cycle begins at puberty and is called menopause.

$C$. Lack of menstruation may be indicative of pregnancy.

$D$. Cyclic menstruation extends between menarche and menopause.

Choose the most appropriate answer from the options given below.

Which organism do not have heterogametes?

Oestrus cycle is seen in