Some cells in the body turn over rapidly. Skin cells constantly bubble up from stem cells in the dermis and blood cells are continuously produced in bone marrow. Other cells live a long time without duplicating, such as most neurons and cells forming the lens of the eye. If all cells lived a uniform medium time span, what consequences might you predict?

The diagram below illustrates a biochemical process that occurs in organisms. What is another name for the substance labeled “catalyst”?  

Some unicellular organisms are motile (have the ability to move) and some are non-motile. Which cellular structures are associated with movement?  

Salivary amylase breaks down starch in your mouth. Amylase makes sure that the breakdown is accelerated. What is the term for a substance that speeds up the rate of a  chemical reaction?

Answer the question in the box below: Mention a renewable resource Mention a non-renewable resource

Identify the nucleolus

Some diseases are caused by the improper functioning of specific cellular organelles. A patient exhibited crowding inside the cells due to the accumulation of old cellular organelles and engulfed particles. Most likely, the symptoms were due to a faulty _____.

In the following food chain, which organism is at the third trophic level? grass → rabbits → snakes → hawks

What is a major difference between facilitated diffusion and active transport?

In which way are photosynthesis and cellular respiration different?