Pollen grains are generally spherical measuring about 25-50 micrometers in diameter.
Question 142 of 501
📘 CLASS XII
Which condition prevents autogamy but not geitonogamy?
If both male and female flowers are present on the same plant such as castor and maize (monoecious), it prevents autogamy but not geitonogamy.
Question 143 of 501
📘 CLASS XII
The stalk attaching the ovule to the placenta is called:
The ovule is a small structure attached to the placenta by means of a stalk called funicle.
Question 144 of 501
📘 CLASS XII
Cells of the nucellus are characterized by:
Cells of the nucellus have abundant reserve food materials.
Question 145 of 501
📘 CLASS XII
In a majority of flowering plants, how many megaspores degenerate?
In a majority of flowering plants, one of the megaspores is functional while the other three degenerate.
Question 146 of 501
📘 CLASS XII
Free nuclear endosperm means:
PEN undergoes successive nuclear divisions to give rise to free nuclei. This stage... is called free-nuclear endosperm... nuclear divisions are not followed immediately by cell wall formation.
Question 147 of 501
📘 CLASS XII
In pea and groundnut, the endosperm is:
Endosperm may either be completely consumed by the developing embryo (e.g., pea, groundnut, beans).
Question 148 of 501
📘 CLASS XII
The portion of the embryonal axis above the level of cotyledons is called:
The portion of embryonal axis above the level of cotyledons is the epicotyl.
Question 149 of 501
📘 CLASS XII
Which part of the flower contributes to the fruit formation in apple?
In a few species such as apple... the thalamus also contributes to fruit formation.
Question 150 of 501
📘 CLASS XII
Parthenocarpy can be induced by the application of:
Parthenocarpy can be induced through the application of growth hormones.
