The question asks for the term that describes an organism composed of a single cell. This is a basic definition in biology, specifically related to the classification of organisms based on their cellular structure.
Correct Option: B) Unicellular — An organism made of a single cell is called unicellular. Examples include bacteria, amoeba, and paramecium.
The question asks to identify a unicellular organism from the given options. A unicellular organism is an organism that consists of a single cell, unlike multicellular organisms which are made up of many cells.
Correct Option: A) Amoeba is a well-known example of a unicellular organism. It is a single-celled eukaryotic organism that belongs to the kingdom Protista.
The question asks to identify the scientists who proposed the Cell Theory. This requires knowledge of the history of biology and the key figures associated with fundamental biological theories.
The Cell Theory is one of the most fundamental principles in biology. It states that all living organisms are composed of cells, and cells are the basic unit of life. It also states that all cells arise from pre-existing cells.
Matthias Schleiden, a botanist, proposed in 1838 that all plant tissues are composed of cells. Theodor Schwann, a zoologist, extended this idea in 1839, stating that all animal tissues are also composed of cells. Together, they formulated the initial Cell Theory. Later, Rudolf Virchow added the third postulate: "Omnis cellula e cellula" (all cells arise from pre-existing cells).
D) Schleiden and Schwann are correctly credited with proposing the Cell Theory. Schleiden studied plants and Schwann studied animals, and their combined work led to the unified theory that all living things are made of cells.
The question asks to identify the cellular organelle known as the 'powerhouse of the cell' and which is absent in non-living things. This requires knowledge of basic cell biology and the functions of various organelles.
Correct Option: A) Mitochondria are responsible for cellular respiration, generating ATP (energy currency of the cell), and are thus rightly called the 'powerhouse of the cell'. As a cellular organelle, they are exclusively found in living cells and are absent in non-living things.
The question asks to identify the term for organisms that can produce their own food using simple inorganic substances like sunlight, carbon dioxide, and water. This directly relates to the fundamental classification of organisms based on their mode of nutrition.
Correct Option: B) Autotrophs are organisms that can manufacture their own food using sunlight, COâ‚‚, and water through processes like photosynthesis.
The question asks why animals are classified as heterotrophs. We need to understand the definition of a heterotroph in biology and compare it with the given options.
Correct Option: D) Depend on organic food from other organisms