The organelle that best enables an athlete’s tissues to be metabolically active are A. ribosomes.B. lysosomes.C. smooth endoplasmic reticulum.D. mitochondria.E. contractile vacuoles.

Microfilaments such as actin, microtubules, and the intermediate filaments form the cell-supporting structure called the ______________. A. cytoplasm B. plasma membrane C. cytoskeleton D. centrioles

The second shell of atom can hold a maximum of____electrons a. two b. four c. eight d. sixteen

Which one of the following properties is not a characteristic of all living organisms? a. Maintenance of relatively stable internal conditions b. Adaptation to environmental factors in ways that influence survival c. Production of nutrients by photosynthesis d. Growth and reproduction e. Response to stimuli

Why is ATP important in living organisms?a. It is easily converted to starch for long-term storage.b. It can transfer some of its energy to other chemicals.c. It is an important structural component of cell membranes.d. Like all other nucleic acids, it stores hereditary information.e. Like RNA, it acts as a source code for the formation of proteins.

To observe the three-dimensional structure of a cell the best type of microscopy would be A. fluorescence microscopy. B. standard light microscopy. C. scanning electron microscopy. D. differential-interference light microscopy. E. transmission electron microscopy.

. ____ is a cell engulfing large solid materials, and ____ is a cell engulfing materials dissolved in solution. A. Endocytosis; exocytosisB. Exocytosis; endocytosisC. Phagocytosis; pinocytosisD. Pinocytosis; phagocytosis

______________ function in the collection, packaging, and distribution of molecules made in the cell.A) MitochondriaB) RibosomesC) Golgi bodiesD) PeroxisomesE) Vacuole

Why does carbon form four covalent bonds? A)Because carbon has a high electronegativity .B)Because carbon needs four electrons to fill its outer shell. C)Because the most common isotope has four neutrons. D)Because carbon tends to give up four electrons to balance the charge of its protons. E)Because carbon has a low electronegativity.

For which of the following organelles are the structure and function correctly described?A) Endoplasmic reticulum—a network of interconnected membranes forming sacs and canals that makes and packages protein molecules for secretionB) Ribosomes—membranous vesicles containing digestive enzymesC) Golgi apparatus—particles, composed of protein and RNA, which synthesize proteinsD) Mitochondrion—non-membranous structure that synthesizes proteins