If one set of chromosomes for a given plant is represented as N; in case of double fertilization, the zygote and the endosperm nucleus of a diploid plant would have how many sets of chromosomes respectively?

In a diploid plant (2N), germ cells or gametes are produced via meiosis and contain a single set of chromosomes (N) [4]. Double fertilization is a unique process in angiosperms involving two sperm cells. The first sperm (N) fuses with the egg cell (N) to form a diploid zygote (2N), which restores the chromosome number for the next generation [5]. Simultaneously, the second sperm (N) fuses with the central cell, which contains two polar nuclei (N+N) [1]. This fusion of three haploid nuclei results in a triploid primary endosperm nucleus (3N) [5]. Therefore, for a plant where N represents one set of chromosomes, the zygote is 2N and the endosperm is 3N. This mechanism ensures the endosperm provides a specialized nutrient source for the developing embryo [5].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 8: Heredity > 8.2.3 How do these Traits get Expressed? > p. 131
2. [3] Science , class X (NCERT 2025 ed.) > Chapter 7: How do Organisms Reproduce? > 7.3.1 Why the Sexual Mode of Reproduction? > p. 120
3. [4] Science , class X (NCERT 2025 ed.) > Chapter 8: Heredity > separate traits, shape and colour of seeds Figure 8.5 > p. 132
4. [2] Science , class X (NCERT 2025 ed.) > Chapter 7: How do Organisms Reproduce? > 7.3.2 Sexual Reproduction in Flowering Plants > p. 121
5. [5] https://www.britannica.com/science/double-fertilization