• Cell Type: Eukaryotic

• Cellularity: Multicellular

• Nucleus: True nucleus with a nuclear membrane enclosing genetic material.

• Organelles: Possess membrane-bound organelles (e.g., mitochondria, endoplasmic reticulum, Golgi apparatus).

• Genetic Material: DNA arranged in multiple linear chromosomes within the nucleus.

• Cell Wall: Absent; cells are surrounded only by a plasma membrane.

• Motility: Most are motile at some stage of life; movement occurs using cilia, flagella, or muscular contractions.

• Reproduction: Mostly sexual reproduction (involving gamete formation and fertilization); some can reproduce asexually.

• Habitat: Found in almost all environments — terrestrial, aquatic (freshwater and marine), and aerial.

→ Nutrition: Heterotrophic Mode

• Heterotrophs: Obtain food by ingesting other organisms or organic matter (cannot synthesize their own food).

• Digestion: Usually internal; food is broken down using enzymes inside a digestive cavity or cells.

• Mode of Nutrition: Holozoic — involves ingestion, digestion, absorption, assimilation, and egestion.