Question

Given below are two statements:
Statement (I):Papaya is a polygamous plant with various sex forms (pistillate, hermaphrodite and staminate)
Statement (II): Pistillate form is stable and sex reversal is not affected by environmental factors
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true.
• B. Both Statement (I) and Statement (II) are false.
• C. Statement (I) is true but Statement (II) is false.
• D. Statement (I) is false but Statement (II) is true.

Hint:

Papaya Sex Forms: Papaya is known for having multiple sex forms (male, female, hermaphrodite), making it polygamous. (Statement I is True)
Sex Stability in Papaya: While pure female plants are stable, hermaphrodite and male plants can show changes in flower type (sex reversal) due to environmental conditions like high temperature. (Statement II is False)

Answer 1

The Correct Option is C

Statement (I): Papaya is a polygamous plant with various sex forms (pistillate, hermaphrodite and staminate). This statement is true. Papaya (Carica papaya) is well-known for its complex sex expression. It is typically dioecious (separate male and female plants) or gynodioecious (female and hermaphrodite plants). Some varieties can produce pistillate (female), staminate (male), and hermaphrodite (bisexual) flowers, sometimes even on the same plant, fitting the description of polygamous. Statement (II): Pistillate form is stable and sex reversal is not affected by environmental factors. This statement is false. While purely pistillate (female) papaya plants are genetically female and generally stable in their sex expression, the sex expression in hermaphrodite and male papaya plants can be influenced by environmental factors such as temperature and soil moisture. High temperatures, for example, can induce "sex reversal" or changes in flower morphology in hermaphrodite plants, leading to an increase in male flowers or sterile flowers (a phenomenon often called "summer sterility"). Purely pistillate (female) forms are indeed genetically stable females, but the blanket statement that "sex reversal is not affected by environmental factors" in all forms, especially in the context of papaya's overall variable sex expression, is incorrect. The instability or changeability of sex forms, particularly in hermaphrodites, due to environment is a known issue. Since Statement (I) is true and Statement (II) is false, option (3) is the correct answer. Statement (I) is true but Statement (II) is false.

Answer 2

Genetic-mechanism approach:
Papaya sex is controlled by a pair of proto-sex chromosomes with three genotypes: XX (pistillate/female), XY (staminate/male) and XY^h (hermaphrodite). Since three distinct sex forms exist in the species, it is correctly described as polygamous, so Statement (I) is true.

However, only the pure genetic determination is fixed; the physical expression of sex is not immune to environment. High temperature and moisture stress are documented to cause hermaphrodite flowers to shift toward maleness (temporary sex reversal / staminate flower production), and even pistillate plants can show occasional carpel abnormalities under stress. So the claim that sex reversal is unaffected by environmental factors does not hold, making Statement (II) false.

Hence, Statement (I) is true and Statement (II) is false - option (3).