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

Bonus   Organs are composed of tissues, which are composed of cells. This is an example of which characteristic of life?A) Living things grow and develop.B) Living things respond to stimuli.C) Living things maintain themselves by homeostasis.D) Living things have levels of hierarchical organization.E) Living things are adapted to the environment.

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

Bonus question

A substance that acts as a reservoir for H+ ions, opposing any increase or decrease in concentration, is a(n) _______. A.buffer B.acid C.base D.antacid

What type of bonding is likely to occur between two water molecules or strands of DNA? A. covalent B. ionic C. hydrogen D. both hydrogen and covalent E. both hydrogen and ionic

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.

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

Plasma membranes are a feature of A. all cells. B. prokaryotic cells only. C. eukaryotic cells only. D. plant cells only. E. animal cells only.

Whether a molecule can cross the plasma membrane depends upon A. the size of the molecule.B. the shape of the molecule.C. the chemical properties of the molecule.D. the charge of the molecule.E. All of the choices are correct.