Science Group
Explore subjects and practice MCQs
7
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Total MCQs
Science Group
Answer: Plants are multicellular autotrophs with cellulose cell walls.
Answer: Eubacteria have cell walls made of peptidoglycan.
Answer: Viruses are obligate intracellular parasites that reproduce only inside host cells.
Answer: Viroids are naked RNA molecules without a protein coat.
Answer: BSE (mad cow disease) is caused by prions, which are infectious proteins.
Answer: Animals are multicellular heterotrophs without cell walls.
Answer: Algae, including seaweeds, are placed in kingdom Protista in the six-kingdom system.
Answer: Genetic diversity is one of the levels of biodiversity, along with species and ecosystem diversity.
Answer: Overexploitation of natural resources is a serious threat to biodiversity.
Answer: Complete destruction of habitat leaves a species unable to survive, leading to extinction.
Answer: In 1665 Robert Hooke used a microscope to observe thin slices of cork and described the tiny box-like units as cells.
Answer: Matthias Schleiden (plants, 1838) and Theodor Schwann (animals, 1839) together proposed the cell theory.
Answer: Rudolf Virchow (1855) added the principle that new cells arise only from pre-existing cells.
Answer: The cell theory does not state that all cells have cell walls or chloroplasts; these are present only in some cells.
Answer: Robert Hooke named the chambers he observed in cork 'cells' because they resembled the small rooms of a monastery.
Answer: In 1831 Robert Brown first described and named the nucleus in plant cells.
Answer: The cell is the smallest unit that can perform all the functions of life.
Answer: Viruses are non-cellular agents, so the statements of the cell theory do not apply to them.
Answer: The cytoplasm is the region between the nucleus and the plasma membrane where organelles float.
Answer: The nucleus is the largest organelle in most cells and contains the genetic material.