Which of the following statements truly describes self-incompatibility in plants?
(A). Self-incompatibility prevents self-fertilization in plants.
(B). Self-incompatibility promotes outcrossing and thus increases genetic diversity within plant populations.
(C). Self-incompatibility is a mechanism that allows plants to self-fertilize efficiently.
(D). Self-incompatibility is controlled by genetic mechanisms within the plant.
(A). Self-incompatibility prevents self-fertilization in plants.
(B). Self-incompatibility promotes outcrossing and thus increases genetic diversity within plant populations.
(C). Self-incompatibility is a mechanism that allows plants to self-fertilize efficiently.
(D). Self-incompatibility is controlled by genetic mechanisms within the plant.
Show Hint
Therefore, it always prevents self-fertilization and encourages cross-pollination.
- (A), (B) and (C) only
- (B), (C) and (D) only
- (A), (C) and (D) only
- (A), (B) and (D) only
The Correct Option is D
Solution and Explanation
Self-incompatibility (SI) is a widespread biochemical and genetic mechanism used by flowering plants to prevent self-fertilization and encourage outcrossing.
It relies on the plant's ability to distinguish between self and non-self pollen.
Step 2: Detailed Explanation:
Let us analyze the truth value of each statement:
- Statement (A): Self-incompatibility prevents fertile, functional hermaphrodite flowers from setting seed when pollinated by their own pollen.
Thus, Statement (A) is correct.
- Statement (B): By blocking self-fertilization, SI forces outcrossing (cross-pollination).
This preserves heterozygosity, reduces inbreeding depression, and increases genetic diversity within the plant population.
Thus, Statement (B) is correct.
- Statement (C): Since the primary function of SI is to block self-pollen germination or pollen tube growth, it prevents self-fertilization rather than facilitating it.
Thus, Statement (C) is incorrect.
- Statement (D): SI is a highly regulated genetic system, typically controlled by one or more multi-allelic loci known as the S-locus.
It can be classified into sporophytic self-incompatibility (SSI) or gametophytic self-incompatibility (GSI) based on whether the pollen phenotype is determined by the diploid parental genotype or the haploid pollen genotype.
Thus, Statement (D) is correct.
Combining the correct statements yields (A), (B), and (D), which matches Option (D).
Step 3: Final Answer:
The correct option is (D) (A), (B) and (D) only.
Top ICAR AIEEA Plant Sciences Questions
- Both plant and animal cells contain some small organelles called 'peroxisomes', which are dedicated to the metabolism of substances such as
- Chemicals that store energy for the majority of work within cells are called
- The longest phase during the eukaryotic cell cycle is
- The formula: [Sum of (Observed-Expected)$^2$/Expected] is also known as
- Human beings have a large-sized 'proteome'. The principal and more significant reason for this is-
Top ICAR AIEEA Genetics & Plant Breeding Questions
Select the correct statements about origin of the tetraploid and hexaploid wheat:
• [A.] The tetraploid species Triticum turgidum is an allopolyploid.
• [B.] The hexaploid species Triticum aestivum is an allopolyploid.
• [C.] Triticum turgidum arose from a combination of Triticum monococcum and Triticum timopheevii genomes.
• [D.] Triticum aestivum arose from a combination of Triticum turgidum and Aegilops tauschii genomes.The physiological characteristics of wheat plants that adapt different wheat cultivars to different climates include-
• [(A).] Fertilizer requirement.
• [(B).] Vernalization requirement.
• [(C).] Winter hardiness (cold tolerance)
• [(D).] Photoperiod response. Choose the correct answer from the options given below:
Male sterile cytoplasm in crop plants usually arises from-
• [(A).] Inter-specific hybridization
• [(B).] Self-incompatibility
• [(C).] Spontaneous mutation
• [(D).] Induced mutation through Ethium Bromide Choose the correct answer from the options given below:
Which of the following statements is NOT correct?
• [(A).] Seeds of synthetic varieties need to be replaced every year.
• [(B).] Hybrid crops need intensive care and more inputs.
• [(C).] Open pollinated progeny test is used in Maize and Pearl millet.
• [(D).] Composite varieties exploit both GCA and SCA. Choose the correct answer from the options given below:
Which of the following combinations of the premises of 'Gamete Selection' in plant breeding is the correct one?
• [(A).] Multiparent crosses are required for simultaneous improvements of multiple traits.
• [(B).] The male parents of the final crosses are heterozygous and hence heterogametic.
• [(C).] Each zygotic seed is a product of a separate, independent fertilization event.
• [(D).] Gametic selection is an effective method to isolate an inbred for hybrid breeding.
Choose the correct answer from the options given below:
Top ICAR AIEEA Questions
- Which of the following statements is false?
- Which of the following is an example of an inventory?
- According to Adam Smith, productivity gains could be brought about through .
- The supply curve for an artificially scarce good is .
- Which of the following would not be considered an opportunity cost of paid employment?