OBJECTIVE FORESTRY

FORESTRY

PLANT AND WOOD ANATOMY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
How does the sperm of flowering plants reach the egg?
A
Via a pollen tube that grows from the pollen grain through the carpel tissues to the egg
B
Via raindrops of a dew film that allows the sperm to swim from the male plant to the female plant
C
Usually via an insect, which places sperm in the ovary while probing for nectar
D
By actively swimming down though the style to the egg
Explanation: 

Detailed explanation-1: -The immobile sperm cells are delivered by the pollen tube toward the ovule harboring the female gametophyte by species-specific pollen tube guidance and attraction mechanisms. After pollen tube burst inside the female gametophyte, the two sperm cells fuse with the egg and central cell initiating seed development.

Detailed explanation-2: -Pollen on the stigma germinates to grow a pollen tube, guided by the pollen nucleus, into the pistil. Within the pollen tube, the reproductive nucleus divides into two sperm nuclei. When the pollen tube reaches the ovule’s micropyle, it releases the two sperm nuclei into the ovule. More items •11-Dec-2015

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