The graph shows the rate of reaction for one enzyme at a range of pH values, with temperature held constant. At which pH does this enzyme work fastest?

The table shows the oxygen bubbles produced per minute when catalase is added to hydrogen peroxide at four temperatures. Which conclusion does the data support?

The graph shows reaction rate as substrate concentration is increased while the amount of enzyme is kept the same. What best explains why the line levels off at the higher concentrations?

A biologist analyzes a molecule and finds it is a chain of amino acids joined by peptide bonds. Which class of macromolecule is it?

A food label shows that a snack is almost entirely starch. Which monomer is that starch built from?

Which macromolecule is built from glycerol and fatty acids?

The enzyme lactase breaks down lactose but has no effect at all on sucrose. Why does lactase act on one sugar and not the other?

What does an enzyme do to the chemical reaction it catalyzes inside a cell?

A cell viewed under a microscope has a cell wall and ribosomes but no nucleus and no membrane-bound organelles. What kind of cell is it?

Which structure is present in a plant cell but absent from an animal cell?

Muscle tissue cells contain far more mitochondria than fat storage cells do. What does that difference suggest about muscle cells?

In a pancreas cell that secretes digestive enzymes, which organelle sorts the finished proteins and packages them into vesicles for export?

A cell's lysosomes stop working. What is the most likely result inside that cell?

Which structure inside the nucleus assembles the subunits of ribosomes?

Which statement is part of the cell theory built up by Schleiden, Schwann and Virchow?

A leaf cell contains both chloroplasts and mitochondria. Why does one cell need both organelles?

Which description of the cell membrane matches the fluid mosaic model?

Plant cells are placed in a concentrated salt solution, and their cytoplasm shrinks away from the cell walls. What happened?

Red blood cells are put into a solution and neither swell nor shrink over 30 minutes. What does that show about the solution?

A root hair cell keeps taking in nitrate ions from soil water even though nitrate is already far more concentrated inside the cell. What must be happening?

Glucose crosses a cell membrane through a transport protein, moving from a higher to a lower concentration, and the cell uses no ATP. What is this process called?

A white blood cell wraps its membrane around a bacterium and takes it into the cell inside a vesicle. Which process is this?

What does it mean to say that the cell membrane is selectively permeable?

Osmosis is the movement of water across a selectively permeable membrane, not the movement of the dissolved solute.

The graph shows the oxygen released by pondweed at different light intensities, with temperature and carbon dioxide held constant. Above which light intensity does more light no longer raise the rate?

The table shows oxygen bubbles per minute released by pondweed under different colors of light at the same intensity. Which conclusion does the data support?

The table shows the total volume of oxygen taken up by germinating peas kept in the dark. What does the pattern indicate?

A leafy plant is sealed in a clear jar in bright light. The graph shows the carbon dioxide level inside the jar. What accounts for the change over the first 30 minutes?

Which equation correctly summarizes photosynthesis?

Where in a plant cell do the light-dependent reactions of photosynthesis take place?

In a eukaryotic cell, where is most of the ATP of cellular respiration produced?

Which statement correctly compares photosynthesis with cellular respiration?

A sprinter's leg muscles run short of oxygen during a race. What does fermentation in those human muscle cells produce from glucose?

Which raw material used by photosynthesis reaches a leaf's cells through the stomata?

The diagram shows the stages of the cell cycle in order. During which labeled stage is the DNA copied, so that each chromosome becomes two identical sister chromatids?

During which phase of mitosis do the chromosomes line up in a single row across the middle of the cell?

A human body cell with 46 chromosomes completes mitosis and cytokinesis. What is produced?

Cancer cells are described as cells whose cell cycle is no longer controlled. What does that description mean?

A cut on the skin heals as new cells fill the gap. Which process produced those new cells?

Why must a growing cell divide instead of simply continuing to get larger?