Apomixis and polyembryony — NEET & JEE Questions

Question 1 · difficulty L1 · recall

What is apomixis?

• A. Vegetative propagation by stem cutting
• B. Fruit formation only after double fertilisation
• C. Pollen formation without meiosis only
• D. Seed formation without fertilisation

Question 2 · difficulty L2 · understanding

What does polyembryony mean?

• A. Occurrence of more than one embryo in a seed
• B. Formation of more than one pollen grain
• C. Development of several ovaries in one flower
• D. Presence of two stigmas

Question 3 · difficulty L2 · understanding

The formation of seeds without fertilisation, seen in some species of Asteraceae and grasses, is called

• A. parthenocarpy
• B. polyembryony
• C. apomixis
• D. vegetative propagation

Question 4 · difficulty L2 · understanding

The occurrence of more than one embryo in a single seed, common in citrus and mango, is known as

• A. apomixis
• B. apospory
• C. double fertilisation
• D. polyembryony

Question 5 · difficulty L3 · application

Why can apomixis be useful in maintaining desirable hybrid characters?

• A. It always increases recombination
• B. It can produce seeds without meiotic segregation and fertilisation
• C. It forces all plants to self-pollinate
• D. It converts hybrids into haploids

Question 6 · difficulty L3 · application

In one species, a diploid egg cell is formed without reduction division and develops into an embryo without fertilisation. In a second species, cells of the nucellus surrounding the embryo sac divide and develop into embryos. Which term applies to each?

• A. Both are apomixis; the second additionally produces polyembryony
• B. The first is parthenocarpy; the second is polyembryony
• C. The first is polyembryony; the second is apomixis
• D. Both are vegetative propagation

Question 7 · difficulty L3 · application

A farmer buys hybrid seed each year because seed saved from the hybrid crop segregates and loses the hybrid characters. Which property, if introduced into the hybrid, would let the farmer keep using seed from the harvest?

• A. Parthenocarpy
• B. Apomixis
• C. Self-incompatibility
• D. Dioecy

Question 8 · difficulty L3 · application

A seed from a mango is planted and gives rise to several seedlings. Which explanation is correct?

• A. The seed contained several zygotes formed by multiple fertilisation
• B. The seed was parthenocarpic and produced clones
• C. The seed was polyembryonic: besides the zygotic embryo, nucellar cells had developed into additional embryos
• D. The endosperm developed into embryos

Question 9 · difficulty L4 · analysis

A seed contains one embryo formed from the zygote and another embryo formed from surrounding maternal tissue. Which phenomenon is illustrated?

• A. Self-incompatibility
• B. Dichogamy
• C. Polyembryony
• D. Triple fusion

Question 10 · difficulty L4 · application

Apomictic embryos derived from a diploid egg or from nucellar cells are genetically identical to the parent plant, while the zygotic embryo in the same seed is not. Which two consequences follow?

• A. Apomictic seedlings show hybrid vigour that the zygotic seedling lacks; both are clones
• B. Both kinds of seedling are identical to the mother
• C. The zygotic seedling is the clone; apomictic seedlings segregate
• D. Apomictic seedlings are clones of the mother plant and preserve its genotype; the zygotic seedling may segregate if the mother was a hybrid