According to the endosymbiotic theory, mitochondria evolved from an ancient aerobically respiring bacterium. This theory helps to explain why which metabolic pathways are located inside the mitochondria?

During the light-dependent reactions of photosynthesis, what is the role of photosystem II?

A biologist discovers a new species of beetle. To name and classify it, she compares its physical traits to other known beetle species. This process is a key part of which scientific field?

The theory of endosymbiosis states that which organelles evolved from ancestral bacteria engulfed by primitive eukaryotic or archaeal ancestors?

The oxygen atom in a water molecule has a much stronger pull on shared electrons than the hydrogen atoms. What is the correct term for this property of an atom that determines its ability to attract shared electrons?

Gold is a valuable metal that cannot be broken down into simpler substances by ordinary chemical means. What is the correct term for a substance like gold?

A biologist observes a cell with a rigid outer layer that provides structural support. The cell also contains a large central vacuole. What type of cell is she most likely observing?

Small, nonpolar molecules, such as oxygen (O2​) and carbon dioxide (CO2​), can pass directly through the cell’s plasma membrane without the help of a transport protein. Why is this possible?

During the citric acid cycle (Kreb’s cycle), molecules such as NAD+ and FAD are reduced to form NADH and FADH2​. What is the importance of these molecules in the overall process of cellular respiration?

An oak tree is a multicellular organism. All of its cells, including those in its leaves and roots, contain a membrane-bound nucleus that holds its DNA. What type of cell makes up the oak tree?