Read the passage carefully and answer the questions based on the passage:
Pollen pistil interaction involves all events from the landing of pollen grains on the stigma until the pollen tube enters the embryo sac (when the pollen is compatible). When a pollen tube grows through the style and enters into the ovules, it finally discharges two male gametes in one of the synergids. Syngamy and triple fusion are two fusion events occur in angiosperms. Thus, angiosperms exhibit double fertilization. The products of these fusions are the diploid zygote and triploid primary endosperm nucleus. Zygote develops into embryo and primary endosperm cell forms the endosperm tissue. The developing embryo passes through different stages before maturation.
If there are 38 chromosomes in the zygote, how many chromosomes will be there in its haploid egg cell?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 19
The zygote forms by syngamy, the fusion of a haploid male gamete with a haploid egg. So the zygote is diploid (2n), and each gamete carries half the zygote’s chromosome number.
Zygote (2n) = 38
Egg cell (n) = 38 ÷ 2 = 19
Option (1) 38 — Incorrect. 38 is the diploid number of the zygote. A haploid egg cannot have it.
Option (2) 57 — Incorrect. 57 is 3n, the number in the triploid endosperm, not in the egg.
Option (3) 19 — Correct. The zygote is diploid (2n = 38), and the egg cell is haploid (n), with half that number: 38 ÷ 2 = 19.
Option (4) 76 — Incorrect. 76 is double the zygote’s number (4n); no cell in the question has it.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.