Q.29 After fertilization, zygote obtains all its plastid and mitochondria genomes
from the maternal parent, this is also named as
- maternal inheritance
- pleiotropic effect
- variegation
- biparental inheritance
After fertilization, the zygote obtains all its plastid and mitochondrial genomes from the maternal parent, a phenomenon known as maternal inheritance.
Option Breakdown
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Maternal inheritance: Correct. Plastids (chloroplasts) and mitochondria in the zygote come almost exclusively from the mother’s egg cell cytoplasm, as sperm contributes negligible organelles.
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Pleiotropic effect: Incorrect. This refers to one gene influencing multiple traits, unrelated to organelle genome transmission.
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Variegation: Incorrect. This describes patchy leaf coloration due to chloroplast mutations or distribution, not inheritance mode.
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Biparental inheritance: Incorrect. This involves genetic material from both parents (e.g., nuclear DNA); plastids/mitochondria are maternally derived.
Introduction
After fertilization, zygote obtains plastid and mitochondria genomes exclusively from the maternal parent through maternal inheritance, a key genetics concept distinguishing cytoplasmic from nuclear transmission. This MCQ pits maternal inheritance against pleiotropic effect, variegation, and biparental inheritance—vital for biology exams like NEET.Maternal Inheritance Mechanism
Egg cells provide nearly all cytoplasm, including mitochondria and plastids with their DNA (mtDNA, cpDNA), while sperm mitochondria are degraded post-fertilization. This uniparental transmission traces lineages maternally and explains mitochondrial disease patterns.
Exceptions are rare, reinforcing the maternal rule in most eukaryotes.
Other Options Explained
These terms relate to genetics but not organelle transmission.
Option Definition Applies Here? Reason Maternal Inheritance Cytoplasmic organelles from mother only Yes Zygote plastids/mitochondria maternal Pleiotropic Effect Single gene multiple traits No Phenotypic, not inheritance mode Variegation Chloroplast sorting in leaves No Visual mutation effect Biparental Inheritance Traits from both parents No Nuclear DNA pattern only Exam Tips for Genetics MCQs
Target “plastid/mitochondrial genomes” keywords for maternal inheritance. Differentiate from biparental (nuclear) and recall cytoplasmic exclusion of paternal organelles. Practice with diagrams of fertilization for clarity.
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