Megasporogenesis and Female Gametophyte (Embryo Sac) — Unsolved Practice Set
Chapter: Sexual Reproduction in Flowering Plants | Topic: Megasporogenesis and Female Gametophyte Embryo Sac
MEGASPOROGENESIS AND FEMALE GAMETOPHYTE (EMBRYO SAC) — UNSOLVED PRACTICE SET
Topic: Megasporogenesis and Female Gametophyte Embryo Sac
Multiple Choice Questions
Q1. The typical female gametophyte (embryo sac) of angiosperms is:
- 8-nucleate, 7-celled
- 7-nucleate, 8-celled
- 4-nucleate, 4-celled
- 8-nucleate, 8-celled
Q2. Out of the four megaspores formed after meiosis, how many typically survive to form the embryo sac?
- All four
- Two
- Three
- Only one
Q3. The specialised thickenings found at the micropylar tip of the synergids are known as the:
- Chalazal apparatus
- Filiform apparatus
- Antipodal complex
- Egg apparatus
Q4. The group of cells located at the chalazal end of a mature embryo sac is called the:
- Synergids
- Antipodals
- Polar nuclei
- Egg apparatus
Q5. Development of the embryo sac from a single functional megaspore is termed:
- Bisporic development
- Tetrasporic development
- Monosporic development
- Polysporic development
Short Answer Questions
Q6. What is the fate of the three non-functional megaspores formed during megasporogenesis?
Q7. Name the cell formed by the fusion of the two polar nuclei, and mention its location within the embryo sac.
Q8. Why are synergids considered important for guiding the pollen tube into the embryo sac?
Q9. Give the cell : nuclei formula of a typical mature angiosperm embryo sac.
Long Answer Questions
Q10. Trace the sequence of events from the megaspore mother cell to the formation of a mature, 7-celled, 8-nucleate embryo sac, describing the three successive mitotic divisions involved.
Q11. Describe the egg apparatus of an angiosperm embryo sac, mentioning the position and function of each of its three cells.
APPLICATION / ANALYSIS
Q12. A botanist studying a certain plant species observes that its embryo sac develops from two megaspores instead of one. Identify the type of development this represents, and explain how it differs from the typical monosporic pattern seen in most angiosperms.
Q13. In an experiment, the two synergids of an embryo sac are destroyed before pollination. Predict what would happen to the pollen tube's ability to reach the egg cell, and give a reason for your answer.