Question

If the cells in the leaves of a maize plant contain 10 chromosomes each, write the number of chromosomes in its endosperm and zygote. Name and explain the process by which an endosperm and a zygote are formed in maize.
[0.5cm]

Hint:

Double fertilization is critical for simultaneous zygote formation and nutrient-rich endosperm development, ensuring seed viability and germination success.

Answer 1

The endosperm contains 30 chromosomes (3n, triploid), while the zygote has 20 chromosomes (2n, diploid). These are formed through double fertilization, unique to angiosperms. One sperm nucleus fertilizes the egg cell, forming the diploid zygote. Simultaneously, another sperm nucleus fuses with two polar nuclei, forming the triploid endosperm. This process ensures both the development of the embryo and the formation of a nutrient-rich tissue (endosperm) for seed nourishment, vital for seed germination and plant growth. % Quick tip