Keystone review
Which of these shows levels of organization in the human body in increasing order of complexity?
cardiac muscle cells cardiac tissue heart (organ) circulatory system
Which of these pathways best shows transformation of energy first by the chloroplasts and then by the mitochondria?
light --> carbohydrate bonds --> ATP
Bacteria are single-celled microorganisms. The cell walls of these microorganisms serve as barriers to chemicals that might affect the processes that occur within a bacterial cell. Antibiotics are a type of substance used to stop bacterial growth. Some antibiotics cause the bacterial cell wall to rupture. The function of which human organ is most like the cell walls of bacteria?
skin
Which two substances are products of photosynthesis and reactants of cellular respiration? 1. water 2. oxygen 3. glucose 4. carbon dioxide
substances 2 and 3
The indicated protein is part of a cell membrane. What is the most likely purpose of this protein?
It attracts unbalanced electrical charges in the cell's environment.
Which statement describes one reason for carbon's central role in macromolecules?
It can form single, double, and triple bonds.
How does the structure of the plasma membrane serve the needs of the cell?
It is embedded with proteins, which permit the passage of certain materials.
Once the energy in an ATP molecule is released, how does the cell most often reuse the ADP molecule that remains?
It is recombined with phosphates for reuse.
Which statement describes how organelles aid in transporting proteins in eukaryotic cells?
Membrane-enclosed proteins leave the ER and merge with the Golgi apparatus.
In the human digestive system, the enzyme pepsin is present in acidic areas, while the enzyme trypsin is present in less acidic areas. Which of these statements most likely describes a difference in how they function?
Pepsin functions optimally at a lower pH level that trypsin.
Which statement is true of all living organisms?
Their genes have instructions for building proteins.
The cells of all organisms contain DNA molecules. Which statement describes these molecules in eukaryotic cells but not in prokaryotic cells?
They are enclosed in membranes.
What structural quality of proteins distinguishes them from other macromolecules?
They have three dimensional shapes determined by their arrangements of amino acids.
Which characteristic is shared by all organisms?
ability to reproduce
