Q.What is Parthenogenesis?
🔒You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Apomixis
Apomixis is the formation of an embryo through an essentially asexual route, without true gamete formation or fertilization, even though it occurs within the flower's normal reproductive structures, meaning no meiosis and no syngamy actually take place, yet the ovule still matures into a seed. Apogamy refers to a gametophytic cell (such as the egg) directly producing an embryo-like structure without fertilization; apospory refers to a diploid sporophytic cell (typically nucellar) directly producing a diploid gametophyte without meiosis (orange, mango). Apomixis is classed into recurrent apomixis (an unreduced embryo sac forms repeatedly, either via diplospory from the diploid megaspore mother cell, as in Taraxacum, or apospory from nucellar cells), non-recurrent apomixis (meiosis proceeds normally to a haploid embryo sac, but the embryo then arises without fertilization via pa …
In normal sexual reproduction a new organism develops from a zygote formed by an egg being fertilised by a sperm; parthenogenesis is defined by what happens when this fertilisation step is bypassed. …
Development of an offspring from an unfertilised egg, without fertilisation.
Parthenogenesis is a form of asexual/uniparental reproduction in which an unfertilised egg (ovum) develops into a complete new individual without being fertilised by a sperm. It is seen naturally in organisms such as honey bees (drones develop from unfertilised eggs), some …
- CBSE 2025Set X11 markQ.Few flowering plants have evolved a special mechanism to produce seeds without fertilization called ____________.
›Reveal solutionSolution
Seed formation without fertilization is called apomixis.
Apomixis is a special mechanism seen in some flowering plants (e.g. some species of Asteraceae and grasses) by which seeds are produced without fertilization. It is a form of asexual reproduction that …
- CBSE 2024Set ANNUAL1 markQ.Define apomixis.
›Reveal solutionSolution
Apomixis is a mechanism to produce seeds asexually, without the fusion of gametes, so the offspring are genetically identical to the mother plant.
Apomixis is a form of reproduction that superficially resembles normal sexual reproduction (the plant still produces seeds) but does not actually involve meiosis or fertilisation — instead, either the diploid egg cell develops into an embryo without fertilisation, or some other diploid cell of the ovule (e.g., the nucellus) directly develops into an embryo. Since no fusion of gametes occurs, all the offspring are genetically identical clones of the parent plant. It is seen in some Citrus and mango varieties, and in many grass species, and is of great interest to plant bree …
- CBSE 2022Set M1 markQ.What is Parthenogenesis?
›Reveal solutionSolution
Development of an offspring from an unfertilised egg, without fertilisation.
Parthenogenesis is a form of asexual/uniparental reproduction in which an unfertilised egg (ovum) develops into a complete new individual without being fertilised by a sperm. It is seen naturally in organisms such as honey bees (drones develop from unfertilised eggs), some …
- CBSE 2022Set ANNUAL1 markMCQQ.A clone is a group of individuals obtained through(a) sexual reproduction(b) hybridization(c) asexual reproduction(d) cross-pollination
›Reveal solutionSolution
Clones are genetically identical individuals produced without gamete fusion, i.e., through asexual reproduction.
A clone is defined as a group of individuals that are genetically identical to one another and to the parent from which they arose. This identity is only possible when offspring are produced by mitotic division of a single parent's cells (vegetative propagation, budding, fragmentation, apomixis, etc.), because mitosis faithfully copies the parental genome without any exchange or recombination of genetic material. Sexual reproduction (option a), hybridization (b), and cros …
- CBSE 2020Set ANNUAL1 markMCQQ.Apomixis is the development of(a) Seeds with fertilization(b) Seeds without fertilization(c) Seeds from vegetative cells(d) Seeds from reproductive cells
›Reveal solutionSolution
Apomixis is a natural asexual short-cut to seed formation, bypassing fertilisation entirely to produce clonal seeds.
Apomixis is a special mode of asexual reproduction found in some flowering plants (e.g., certain species of Asteraceae and grasses, and citrus) in which seeds are produced without the actual fusion of male and female gametes — i.e., without fertilisation. The embryo instead develops directly from a diploid cell, such as a cell of the nucellus or an unreduced egg cell, so the resulting seed and the plant it grows into are genetically identical to the m …
- CBSE 2019Set ANNUAL1 markQ.Define Agamospermy.
›Reveal solutionSolution
Agamospermy is asexual seed formation - a form of apomixis where seeds develop without the fusion of gametes.
Apomixis is a mechanism that produces seeds asexually without meiosis and syngamy, so the offspring are genetically identical (clones) of the parent plant. Agamospermy is one of its forms: instead of the egg cell being fertilized by a male gamete, the embryo arises directly from an unfertilized diploid cell of the ovule - most commonly a nucellar cell, a synergid, or an antipodal cell - which divides mitotically to form the embryo while the rest of the ovule develops into a normal-looking seed. Because no fertilization occurs, agamospermy is exploited commercially (e.g. in some Citrus and mango varieties, and by plant breeders working on …
- CBSE 2018Set ANNUAL1 markQ.Define apomixis.
›Reveal solutionSolution
Apomixis is a mechanism by which a plant produces seeds asexually, without meiosis or fertilization occurring, so the seed is genetically identical to the mother plant even though it looks like a normal sexually-produced seed.
In many flowering plants (e.g. some species of Citrus, Mango, and grasses such as Asteraceae and Poaceae members), a diploid cell of the ovule - such as the nucellus - starts dividing and develops directly into an embryo, without the normal steps of meiosis (formation of haploid gametes) and syngamy (fusion of gametes). This process is called apomixis, and it is a special adaptation in flowering plants for asexual reproduction through seeds (also called agamospermy). Because no genetic recombination occurs, the offspring are genetically identical clones of the parent plant. Apomixis is of great interest to plant breeders because hybrid seed varieties, which are usually costly to produce every generation (as hybrid vigour is lost in the next generation rais …
- CBSE 2018Set BOTANY1 markQ.Define apomixis.
›Reveal solutionSolution
Apomixis is a mechanism by which seeds are formed without fertilisation, so it is essentially asexual reproduction disguised as sexual reproduction — the resulting embryo is a clone of the mother plant.
Explanation
In apomixis, the embryo develops directly from a diploid cell of the ovule — for example, from the nucellus, or from a diploid egg cell formed without meiosis — instead of from the fusion of a haploid egg and a haploid sperm. Because no genetic recombination or fertilisation occurs, the seed produced carries an embryo that is genetically identical to the mother plant (a clone).
…
🎓Unlock everything free for 14 days
- ✓Full step-by-step solutions
- ✓Concept-first explanations
- ✓Methods, shortcuts & mistakes
- ✓PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.