Assertion: In organisms belonging to fungi and algae, zygote develops a thick wall that is resistant to dessication and damage.

Reason : In organisms with haplontic life cycle, zygote divides by meiosis to form haploid spores that grow into haploid individuals.

Both Assertion (A) and reason (R) are correct and but R is not the correct explanation of A.

The correct answer is Option (2)- Both Assertion (A) and reason (R) are correct and but R is not the correct explanation of A.

Formation of the diploid zygote is universal in all sexually reproducing organisms. In organisms with external fertilisation, zygote is formed in the external medium (usually water), whereas in those exhibiting internal fertilisation, zygote is formed inside the body of the organism. Further development of the zygote depends on the type of life cycle the organism has and the environment it is exposed to. In organisms belonging to fungi and algae, zygote develops a thick wall that is resistant to dessication and damage. It undergoes a period of rest before germination. In organisms with haplontic life cycle zygote divides by meiosis to form haploid spores that grow into haploid individuals. Zygote is the vital link that ensures continuity of species between organisms of one generation and the next. Every sexually reproducing organism, including human beings begin life as a single cell–the zygote.