Exams › NEET › Biology › Sexual Reproduction in Flowering Plants
118 questions with worked solutions.
Q1. Which of the following is without exception in angiosperms?
Answer: double fertilisation
Double fertilisation is a hallmark of angiosperms: one male gamete fuses with the egg to form the zygote, and the other fuses with the polar nuclei to form endosperm. The other options are not universal because vessels, secondary growth, and autotrophic nutrition all have exceptions in angiosperms.
Q2. Anthesis is a phenomenon which refers to:
Answer: opening of flower bud
Anthesis is the period when a flower opens and becomes functionally ready for pollination. That matches the opening of the flower bud, not pollen formation or pollen reception.
Q3. What is common between vegetative reproduction and apomixis?
Answer: Both produces progeny identical to the parent
Vegetative reproduction and apomixis are both forms of asexual reproduction, so they do not create new genetic combinations. As a result, the progeny are genetically identical to the parent.
Answer: Parthenogenesis
Parthenogenesis is the development of an embryo from an unfertilised female gamete. The other options involve self-fertilisation, fruit development without fertilisation, or fusion of gametes.
Q5. Which one of the following statements is correct?
Answer: Tapetum nourishes the developing pollen
Tapetum is the innermost layer of the anther wall and provides nutrition to the developing microspores/pollen grains. The other options are incorrect because sporogenous tissue is diploid, endothecium aids anther dehiscence, and the hard outer pollen wall is exine, not intine.
Q6. Wind pollinated flowers are
Answer: small, producing large number of dry pollen grains
Wind-pollinated flowers are usually small and inconspicuous because they do not need to attract pollinators. They produce many dry, light pollen grains so the wind can carry them efficiently.
Q7. Which one of the following is surrounded by a callose wall?
Answer: microspore mother cell
The microspore mother cell is enclosed by a callose wall during microsporogenesis to isolate it while meiosis produces microspores. The other options are later or different reproductive stages and are not surrounded by callose in this way.
Q8. Unisexuality of flowers prevents
Answer: autogamy and geitonogamy
Unisexual flowers have either stamens or carpels, not both. So pollen cannot fertilize the same flower (autogamy), and flowers on the same plant cannot exchange pollen as geitonogamy requires separate male and female flowers on one plant; only xenogamy remains possible.
Q9. What does the filiform apparatus do at the entrance into ovule?
Answer: It helps in the entry of pollen tube into a synergid
The filiform apparatus is a specialized thickening in the synergids near the micropylar end of the ovule. It helps attract and guide the pollen tube into a synergid for discharge of male gametes.
Q10. Development of an organism from female gamete/egg without involving fertilization is
Answer: Parthenogenesis
Parthenogenesis is the development of an organism from an egg or female gamete without fertilization. The other choices refer to different processes: parthenocarpy is seedless fruit formation, polyembryony is formation of multiple embryos, and adventive embryony is embryo formation from somatic tissues.
Q11. Nucellar embryo is
Answer: Apomictic diploid
A nucellar embryo arises from nucellus cells of the ovule without fertilization, so it is apomictic. Because it develops from somatic maternal tissue, it is diploid rather than haploid.
Q12. The polyembryony commonly occurs in
Answer: citrus
Polyembryony means the formation of more than one embryo in a single seed. It is commonly seen in citrus, where nucellar embryos often develop alongside the zygotic embryo.
Q13. Which of the following has proved helpful in preserving pollen as fossils?
Answer: Sporopollenin
Sporopollenin is an exceptionally tough, chemically inert biopolymer in the outer pollen wall, so it resists decomposition and fossilizes well. The other options are not known for providing this long-term preservation.
Q14. Double fertilization is exhibited by :
Answer: Angiosperms
Double fertilization is a unique feature of angiosperms, where one male gamete fuses with the egg to form the zygote and the other fuses with the polar nuclei to form endosperm. This process does not occur in algae, fungi, or gymnosperms.
Q15. Male gametophyte in angiosperms produces:
Answer: Two sperms and a vegetative cell
The male gametophyte of angiosperms is the pollen grain. Its generative cell divides to form two sperm cells, while the vegetative (tube) cell remains to support pollen tube growth.
Q16. In angiosperms, microsporogenesis and megasporogenesis :
Answer: involve meiosis
Microsporogenesis and megasporogenesis are the formation of microspores and megaspores from diploid mother cells, and this requires meiosis. The resulting haploid spores later develop into gametophytes, so the key feature is reduction division, not direct gamete formation.
Q17. In angiosperms, functional megaspore develops into
Answer: embryo sac
In angiosperms, the functional megaspore is the one that survives and divides mitotically to form the embryo sac, which is the female gametophyte. The ovule contains it, while endosperm forms only after fertilization and pollen sac is male-related.
Q18. Coconut water from a tender coconut is
Answer: Free nuclear endosperm
Coconut water is the liquid free-nuclear endosperm present in the tender coconut. It is not seed coat, nucellus, or embryo tissue.
Answer: 63
Root tip cells are somatic and therefore diploid, so 42 chromosomes means 2n = 42. Aleurone cells are part of the endosperm tissue in flowering plants and are typically triploid (3n), so they have 63 chromosomes.
Q20. Perisperm is
Answer: persistent nucellus
Perisperm is the persistent nucellus of the ovule that remains in the seed as a storage tissue. It is not endosperm, which develops after fertilization from the primary endosperm nucleus.