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Most NEET questions on this topic are short, but they test whether you can reason about it: which embryos in a seed are genetically identical to the parent, why apomixis is not parthenocarpy, and why seed companies care. This post covers what the NCERT chapter says, works through the genetics, and connects it to recent research on hybrid rice.
Where is this in the syllabus?
The NEET (UG) 2026 syllabus, Unit 6 Reproduction, lists under sexual reproduction in flowering plants "Special modes- apomixis, parthenocarpy, polyembryony". The text is section 1.5 of the NCERT Class 12 Biology chapter Sexual Reproduction in Flowering Plants, in the 2026-27 reprint. Check the syllabus for your exam year.
What is apomixis?
NCERT defines it as a special mechanism by which some flowering plants, "such as some species of Asteraceae and grasses", produce seeds without fertilisation, and calls it "a form of asexual reproduction that mimics sexual reproduction". It describes two routes:
From the egg. In some species, the diploid egg cell is formed without reduction division and develops into the embryo without fertilisation.
From the nucellus. More often, as in many Citrus and mango varieties, some nucellar cells surrounding the embryo sac start dividing, protrude into the embryo sac and develop into embryos.
The nucellus is maternal tissue, part of the ovule, so an embryo grown from it has the mother plant's genotype.
What is polyembryony?
NCERT defines polyembryony as the occurrence of more than one embryo in a seed. In the Citrus and mango varieties above, it says, each ovule contains many embryos. NCERT suggests a simple activity: squeeze an orange seed and count the embryos of different sizes and shapes.
Worked reasoning: which embryos are clones?
A Citrus seed (a hypothetical example) contains four embryos: one formed after fertilisation, and three from nucellar cells. How many are genetically identical to the mother plant?
The zygotic embryo came from an egg (formed by meiosis) fused with a male gamete. It has a new combination of genes, so it is not a clone.
The three nucellar embryos came from diploid maternal cells by mitosis. They are genetically identical to the mother, and to each other.
Answer: three. NCERT asks this as a question: "What would be the genetic nature of apomictic embryos? Can they be called clones?" The answer is yes, for embryos like these.
Now the ploidy. If the plant is diploid (2n), the nucellar embryos are 2n because the nucellus is 2n. An embryo from an unreduced egg is also 2n, because no reduction division took place. The zygotic embryo is 2n too, but from n + n. Same ploidy, different genetics: that is the distinction questions test.
Why do breeders want apomixis?
NCERT explains the problem. Hybrid crop varieties raise yields, but seeds collected from a hybrid give plants that segregate and lose the hybrid's traits, so farmers must buy new hybrid seed every year. If hybrids could be made apomictic, "there is no segregation of characters in the hybrid progeny", and farmers could resow their own seed.
That is what recent research has worked towards in rice. Khanday and colleagues (2019) showed that expressing the gene BABY BOOM1 in the egg cell was enough to trigger embryo development without fertilisation, and when combined with edits that replace meiosis with mitosis, gave clonal progeny that kept the parent's heterozygosity. Wang and colleagues (2019) edited four genes in hybrid rice to obtain plants that could propagate clonally through seeds. In the inbred rice lines that first combined these steps, only 10 to 30% of seeds were clonal. Vernet and colleagues (2022) reported hybrid rice plants producing more than 95% clonal seeds across multiple generations, keeping the hybrid's phenotype.
These are research results, not seeds farmers can buy, and they are not part of the NEET syllabus. They show why NCERT says active research is going on in this area.
Common mistakes and how to avoid them
Calling apomixis sexual because it makes seeds. It produces seeds, but without fertilisation, so it is asexual.
Mixing up apomixis and parthenocarpy. Seed versus fruit, as in the callout.
Assuming every embryo in a polyembryonic seed is a clone. The zygotic one is not.
Placing nucellar embryos outside the ovule. The nucellus is ovule tissue around the embryo sac.
Our post on flowering plant reproduction covers double fertilisation and endosperm, which you need to contrast with these special modes.
A practice routine
Day 1: Write the NCERT definitions of apomixis, polyembryony and parthenocarpy from memory, with one example each.
Day 2: Draw an ovule and label where nucellar embryos arise.
Day 3: Answer three "how many are clones?" questions of your own design.
Day 4: Explain in four sentences why apomictic hybrids would save farmers money.
If the parts of the ovule still blur together, the Fermi Concept Library covers every concept in physics, chemistry, biology, mathematics and computing, each with its own lesson.
Today, answer NCERT's end-of-chapter question 18, "What is apomixis and what is its importance?", in under 60 words.
