Biology Unit 1.1 Test

Some cells, such as human nerve and muscle cells, contain many more mitochondria than do other cells. Why do some cells have more mitochondria than others?

• The cells use more energy.

• The cells store more nutrients.

• The cells degrade more proteins.

• The cells divide more frequently.

A scientist treats a cell with a chemical that destroys the ribosomes. As a result, which cell process will be stopped?

• osmosis

• photosynthesis

• protein synthesis

• respiration

Many land plants store energy in starch (almidón). When energy is needed, the starch molecules can be broken down quickly. This chemical reaction produces which of the following?

• amino acids

• lipids

• monosaccharides

• RNA chains

Based on the graph, which of the following conclusions can be made about the functioning of catalase?

• Catalase works best at 34°C.

• Catalase is destroyed at 34°C.

• Catalase cannot function at 51°C.

• Catalase functions most efficiently at 51°C.

Use the diagram below to answer the following question: What can be concluded from this graph?

• The reactants have less energy than the products.

• The enzyme is consumed during the course of the reaction.

• The enzyme lowers the energy of activation for the reaction.

• The amount of free energy produced in the reaction increases with the enzyme.

A person with swollen gums (encías inflamadas) rinses his mouth with warm salt water, and the swelling decreases. Which has occurred?

• The swollen gums have absorbed the saltwater solution.

• The saltwater solution lowers the temperature of the water in the gums.

• The salt in the solution has moved against the concentration gradient.

• The water in the gums has moved from a high to a low concentration of water.

An osmosis investigation was conducted using chicken eggs to represent cells with semipermeable membranes. Based on this experiment, which of the following should be inferred about cells with semipermeable membranes?

• Substances other than water may also cross the cell membrane.

• Substances other than water may block pores in the cell membrane.

• Water enters the cell when placed in environments of high water concentration.

• Water leaves the cell when placed in environments with a low concentration of solutes.

Which of the following are mainly cycled through the process of photosynthesis and cellular respiration?

• carbon and sulfur

• carbon and oxygen

• nitrogen and sulfur

• nitrogen and oxygen

The diagram below shows the relationship between photosynthesis and cellular respiration and the organelles in which they occur. Which statement describes how photosynthesis and cellular respiration are interrelated?

• Oxygen is produced during cellular respiration and stored during photosynthesis.

• Carbon dioxide and water released by cellular respiration are used in photosynthesis.

• Photosynthesis releases the energy that is stored during the process of cellular respiration.

• Glucose is used during cellular respiration to produce food that is broken down during photosynthesis.

After 24 hours, the amount of gas that accumulated at the top of an inverted test tube is measured. The students conclude that the light source is causing the water to evaporate, causing water vapor to fill the top of the tube. The best alternative explanation of the differences between the setups is that the

• gravity increased the downward flow of the trapped water

• metabolism of the elodea plants absorbed CO2 from the water

• heat from the light source caused the escape of the dissolved gas

• light caused the elodea plants to photosynthesize, releasing O2 gas