Explanation

Aldol condensation requires at least one α-hydrogen (hydrogen on the carbon next to the carbonyl group).

Benzaldehyde and formaldehyde lack α-hydrogens, so they cannot undergo Aldol condensation.

Explanation

The d subshell has 5 orbitals, each can hold 2 electrons, so total 10 electrons.

This is standard in electron configuration rules in chemistry.

Explanation

The formula to calculate max electrons in an orbit is 2n², where n = orbit number.

1st orbit (n = 1): 2 × 1² = 2 electrons

2nd orbit (n = 2): 2 × 2² = 8 electrons

For the 3rd orbit (n = 3): 2 × 3² = 18 electrons

Explanation

Pair production occurs when a high-energy γ-ray photon is converted into an electron and a positron near a nucleus.

It is a quantum phenomenon that requires photon energy greater than 1.022 MeV.

Explanation

Echinoderms (like starfish and sea urchins) are marine animals found only in oceans.

Other groups like fishes, insects, and amphibians can live in freshwater or land environments as well.

Explanation

Explanation

The nucleus is the control center of the cell, regulating all cellular activities, including growth and reproduction.

It contains the cell’s genetic material (DNA).

Explanation

At temperatures above the optimum, enzymes lose their three-dimensional shape — a process called denaturation.

Denatured enzymes cannot bind substrates properly, leading to a rapid drop in reaction rate.

Explanation

Diatoms are microscopic algae and a major component of phytoplankton in aquatic ecosystems.

They play a key role in oxygen production and the marine food chain.

Explanation

A hypothesis is a testable, tentative explanation for a biological problem, based on initial observations.

It guides experiments and is later validated or refuted.