Select the incorrect statement:

In a practical test, a student has to identify the organisms in which syngamy does not occur. In those organisms, the female gamete undergoes development to form new organisms without fertilization. This phenomenon is called "$X$". Identify the organisms and the phenomenon "$X$".

Explain the senescence phase.

Study the following statements and choose the correct option:
$I$. Asexual reproduction is common among single-celled organisms and organisms with relatively simple organization.
$II$. Conidia,bud,and gemmules are common sexual structures.
$III$. Runner,rhizome,sucker,tuber,offset,and bulb are vegetative propagules.
$IV$. The invasive weed found growing in freshwater bodies is $Zostera$.

Which of the following statements is incorrect?
$(i)$ Bamboo species flower only once in their lifetime,generally after $50-100$ years,produce a 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 the same duration in all organisms.
$(iv)$ The juvenile phase is the period of growth between the birth of an individual until it reaches reproductive maturity.

Choose the incorrect statement.