NIOS Class 12 Biology — Important Questions 2026

A student observes that certain bacteria thrive in hot springs with highly acidic conditions and low oxygen levels. These bacteria most likely belong to which group of Archaebacteria?

Euglena is described as a 'connecting link' between plants and animals. Which combination of features BEST justifies this description?

In the life cycle of Plasmodium, malaria is caused when the parasite undergoes its asexual phase in the human body. Which specific event in the human body directly causes the characteristic fever and chills of malaria?

Diatoms are described as unique among protoctists due to the composition of their cell walls. Why are diatom deposits (diatomaceous earth) commercially and industrially important?

Which of the following plants belongs to the family Fabaceae (Papilionaceae)?

In the family Malvaceae, the stamens are joined together by their filaments to form a tube. This condition is called:

The fruit of Poaceae (grass family) is called:

Which phylum of animals is characterised by the presence of cnidoblasts (stinging cells)?

Which of the following is present in plant cells but NOT in animal cells?

The movement of water molecules from a region of higher concentration to lower concentration through a semipermeable membrane is called:

Lysosomes are called 'suicidal bags' because they:

In a prokaryotic cell, the ribosomes are of which type?