Double fertilisation — practice questions

Question 1 · difficulty L1 · recall

What two fusion events together constitute double fertilisation in angiosperms?

• A. Syngamy and triple fusion
• B. Pollination and germination
• C. Meiosis and mitosis
• D. Microsporogenesis and megasporogenesis

Question 2 · difficulty L2 · understanding

What is formed by syngamy in an angiosperm embryo sac?

• A. A triploid primary endosperm nucleus
• B. A diploid zygote
• C. A haploid endosperm
• D. A diploid antipodal cell

Question 3 · difficulty L3 · understanding

Which one of the following is a triploid cell?

• A. Synergid
• B. Central cell
• C. Zygote
• D. Primary endosperm cell

Question 4 · difficulty L3 · understanding

In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are :

• A. Antipodals, synergids, and primary endosperm nucleus
• B. Synergids, Zygote and Primary endosperm nucleus
• C. Synergids, antipodals and Polar nuclei
• D. Synergids, Primary endosperm nucleus and zygote

Question 5 · difficulty L3 · application

What is the usual ploidy of the primary endosperm nucleus formed by triple fusion?

• A. Diploid
• B. Haploid
• C. Triploid
• D. Tetraploid

Question 6 · difficulty L4 · analysis

A pollen tube releases two male gametes into a normal embryo sac. One fuses with the egg, but the second cannot fuse with the central cell. Which product will fail to form normally?

• A. Seed coat from integuments
• B. Zygote
• C. Pollen tube
• D. Primary endosperm nucleus

Question 7 · difficulty L5 · analysis

An embryo sac has one egg nucleus and two polar nuclei, all haploid. After normal double fertilisation, what are the ploidies of the zygote and primary endosperm nucleus?

• A. Diploid and triploid
• B. Triploid and diploid
• C. Haploid and triploid
• D. Diploid and diploid