1 The nature and variety of living organisms

MRS GREN

MRS GREN

An acronym representing the characteristics of living organisms: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.

Eukaryotic Organisms

Multicellular organisms that include plants, animals, fungi, and protists, characterized by having cells with a nucleus.

Common Features of Plants

Multicellular, contain chloroplasts for photosynthesis, have cellulose cell walls, store carbohydrates as starch or sucrose.

Common Features of Animals

Multicellular, lack chloroplasts and cell walls, possess nervous coordination, move, and store carbohydrates as glycogen.

Fungi Characteristics

Non-photosynthetic organisms organized into mycelium with hyphae, with chitin cell walls; they feed through saprotrophic nutrition.

Protists

Microscopic single-celled organisms, some resembling animals and others resembling plants, like Amoeba and Chlorella.

Prokaryotic Organisms

Single-celled organisms, such as bacteria, lacking a nucleus, containing a circular DNA chromosome.

Pathogen

Disease-causing microorganisms, which may include fungi, bacteria, protists, or viruses.

Viruses

Not living organisms; parasitic entities that reproduce inside living cells; consist of a protein coat and nucleic acid.

Lactobacillus bulgaricus

A rod-shaped bacterium used in the production of yogurt from milk.

Pneumococcus

A spherical bacterium that causes pneumonia.

Tobacco Mosaic Virus (TMV)

A virus that infects plants, causing discoloration of leaves and preventing chloroplast formation.

HIV

A virus that leads to AIDS and spreads through bodily fluids.

Influenza Virus

A virus that infects humans and causes flu-like symptoms.