Biology Midterm

Two test tubes were filled with a solution of bromthymol blue. A student exhaled through a straw into each tube, and the bromthymol blue turned yellow. An aquatic green plant was placed into each tube, and the tubes were corked. One tube was placed in the dark, and one was placed in direct sunlight. The yellow solution in the tube in sunlight turned blue, while the one in the dark remained yellow. Which statement best explains why the solution in the tube placed in sunlight returned to a blue color?

• Oxygen was produced by photosynthesis.
• Carbon dioxide was removed by photosynthesis.
• Carbon dioxide was produced by respiration.
• Oxygen was removed by respiration.

Using a microscope in the science lab, Jill observed two unknown cells: Cell 1 and Cell 2. Cell 1 she identified as a plant cell and Cell 2 as an animal cell. Her teacher told her she identified the cells correctly. What did Jill most likely observe to correctly identify the cells?

• Cell 2 had a cell membrane and Cell 1 did not.
• Cell 1 had a cell wall and Cell 2 did not
• Cell 2 had a chloroplast and Cell 1 did not.
• Cell 1 had a nucleus and Cell 2 did not

Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enable it to move from the roots to the leaves of plants?

• Water expands as it freezes.
• Water is an excellent solvent.
• Water exhibits cohesive behavior
• Water is able to moderate temperature.

Large bodies of water, such as lakes and oceans, do not quickly fluctuate in temperature. What is the reason for this phenomenon?

• Water is an acid.
• Water is a versatile solvent.
• Water acts as a buffer.
• Water has a high heat capacity.

Water is often called the "universal solvent" because many substances can be dissolved in water. What properties of water allow it to be such a versatile solvent?

• purity and polarity
• polarity and cohesion
• high heat capacity and adhesion
• expansion upon freezing and solvency

Jake conducted an experiment with four bean plants. They were placed next to one another on a sunny windowsill. He gave each plant equal amounts of different types of water. The plants were given tap water, distilled water, flavored water, or carbonated water. He made the following observations after three weeks. Based on his results, Jake concluded that tap water is not good for plants. How can Jake change his experimental design to improve the validity of his results?

• carry out multiple trials, and increase the number of plants that are given each type of water
• establish a control group that includes different types of plants
• establish another dependent variable to generate more data
• carry out multiple trials that include fewer plants, and increase the types of water given

Coyotes are opportunistic predators that are found throughout most of North America. They typically feed on small mammals, insects, and fruits and vegetables. They are known for their dietary adaptability. The best description of their role in the food web would be:

• herbivore
• carnivore
• detrivore
• omnivore

A food chain is illustrated below: The arrows represented as most likely indicate

• Energy released from metabolism into the environment as heat.
• Oxygen released from metabolism produced by cellular respiration.
• The absorption of energy from the environment that has been created.
• The transport of glucose away from the organism through photosynthesis.

If several species of carnivores are removed from an ecosystem, the most likely effect on the ecosystem will be:

• increase in population stability
• increase in abiotic factors
• decrease in abiotic factors
• decrease in population stability

The diagram below shows the cycling of nutrients in an ecosystem. The removal of which of the following groups would cause an immediate decrease in the amount of energy flowing through the system?

• Consumers
• Producers
• Decomposers
• Inorganic nutrients