After culturing the anther of a plant, a few diploid plants were found along with haploid plants. The diploid plants could have arisen from
Generative cell of pollen
Cells of anther wall
Vegetative cell of pollen
Exine of pollen wall
In Ophioglossum (a fern) chromosome number in gamete ..... and in potato chromosome number in gamete is ....
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.
Select the incorrect pair :
Identify $X, Y$ and $Z$ and select the correct option
What is the major disadvantage of external Fertilization ?