Explanation

• All cells arise from pre-existing cells — this is cell theory.
• Confirmed by Rudolf Virchow (1855): "Omnis cellula e cellula" (every cell from a cell).
• New cells form through cell division — mitosis (growth/repair) and meiosis (reproduction).
• No cell appears spontaneously; all trace back to an earlier cell.

Explanation

Discoverer of Cell: Robert Hook

Robert Hook described the cell as: Basic unit of life

Explanation

Deserts have harsh conditions (extreme temperatures, low water), supporting fewer species.

This results in lower biodiversity compared to forests or grasslands.

Explanation

Explanation

Euglena is a unicellular organism, a key characteristic of many Protista.

Although it is eukaryotic and lives in water, being unicellular is the main reason it’s classified under Protista.

Explanation

A species is defined as a group of organisms that can mate and produce fertile offspring.

Organisms in different genera generally cannot produce fertile offspring.

Explanation

Pheretima posthuma is the common species of earthworm found in South Asia.

It belongs to the phylum Annelida.

It is important for soil fertility.

Explanation

In 1969, Whittaker proposed a system of classification that divided all living organisms into five kingdoms:

1. Monera (bacteria and cyanobacteria)
2. Protista (protozoa, algae, and slime molds)
3. Fungi (mushrooms, molds, and yeasts)
4. Plantae (plants)
5. Animalia (animals)

Explanation

Explanation

The correct expression is "kept me waiting", where "waiting" is the present participle, indicating an ongoing action.

It means he made me wait for a period of time.