Answer: The haploid megaspore nucleus divides, and an embryo sac is said to form. It has six haploid cells with no cell walls and two haploid nuclei. The embryo sac formation occurs in two stages: Stage 1: Megasporogenesis occurs in the first stage, when a single diploid mother cell undergoes meiosis, resulting in the formation of a haploid megaspore tetrad.
Three of these disintegrate, while one survives and develops into the embryo sac.
Stage 2: Megagametogenesis is the second stage, in which the embryo sac is generated by mitosis of the functioning haploid megaspore, resulting in an 8-nucleate, 7-celled gametophyte.
Out of all eight nuclei, the polar nuclei travel to the centre to join and form a single diploid cell at that site (centre).
The triploid endosperm is formed when this single diploid cell unites with the sperm.
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west of the geographic north. The north tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points above the horizontal. The horizontal component of the earth’s field is measured to be 
Specify the direction and magnitude of the earth’s field at the location.At a certain location in Africa, a compass points 
and 
carrying currents of 
and 
in the same direction are separated by a distance of 
. Estimate the force on a 
section of wire A.
wire carrying a current of 
is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be 
. What is the magnetic force on the wire?
and making an angle of 
with the direction of a uniform magnetic field of 
. What is the magnitude of the field 
at a point 
from the wire?
-turns carrying current 
.
is at distance 
from the wire. Find the force acting on the electron if its velocity is directed towards the wire.