Module: | Pollination & Outbreeding Devices
Q50: Consider the following statements regarding structural arrangements that prevent inbreeding:
1. In monoecious plants like castor and maize, the presence of separate male and female flowers on the same plant prevents both autogamy and geitonogamy.
2. In dioecious plants like papaya and date palm, male and female flowers are borne on completely different individual plants.
3. Dioecy represents the absolute structural guarantee against both autogamy and geitonogamy, enforcing obligate xenogamy.
Which of the above statements is/are correct?
2. In dioecious plants like papaya and date palm, male and female flowers are borne on completely different individual plants.
3. Dioecy represents the absolute structural guarantee against both autogamy and geitonogamy, enforcing obligate xenogamy.
Which of the above statements is/are correct?
✅ Correct Answer: B
The correct option is B. Statements 2 and 3 are correct, but Statement 1 is incorrect.
Plants employ varied structural architectures to prevent inbreeding depression.
Monoecy is a condition where a single plant bears both staminate (male) and pistillate (female) flowers.
This spatial separation successfully prevents autogamy (pollen falling on the stigma of the same flower). However, Statement 1 is fundamentally flawed because monoecy cannot prevent geitonogamy (pollen transferring between different flowers on the same plant), as they share identical genetics.
To achieve complete genetic outbreeding, evolution produced dioecy.
In dioecious species like papaya, a plant is entirely male or entirely female.
Because there is no proximity of opposite-sex organs on the same genetic individual, dioecy completely physically eliminates both autogamy and geitonogamy, strictly enforcing cross-pollination (xenogamy).
Plants employ varied structural architectures to prevent inbreeding depression.
Monoecy is a condition where a single plant bears both staminate (male) and pistillate (female) flowers.
This spatial separation successfully prevents autogamy (pollen falling on the stigma of the same flower). However, Statement 1 is fundamentally flawed because monoecy cannot prevent geitonogamy (pollen transferring between different flowers on the same plant), as they share identical genetics.
To achieve complete genetic outbreeding, evolution produced dioecy.
In dioecious species like papaya, a plant is entirely male or entirely female.
Because there is no proximity of opposite-sex organs on the same genetic individual, dioecy completely physically eliminates both autogamy and geitonogamy, strictly enforcing cross-pollination (xenogamy).