The organelle that produces the majority of cellular energy in the form of ATP is the:

• Lysosome

• Mitochondrion

• Ribosome

• Nucleus

• Golgi apparatus

The plasma membrane provides a selective barrier between the intracellular and extracellular environments. Its basic framework is formed by:

• A single layer of lipids

• A double layer of phospholipids with embedded proteins

• A continuous layer of carbohydrates

• Cholesterol molecules only

• A network of collagen fibers

Proteins synthesized in the rough endoplasmic reticulum are further processed and packaged in the:

• Lysosomes

• Mitochondria

• Golgi apparatus

• Nucleolus

• Peroxisomes

Intracellular digestion and removal of worn-out organelles occur through the activity of:

• Ribosomes

• Peroxisomes

• Lysosomes

• Centrioles

• Endosomes

Ribosomes are essential for cellular metabolism because they are responsible for:

• Synthesis of proteins from messenger RNA

• Production of ATP by oxidative reactions

• Storage of calcium ions

• Breakdown of waste products

• Regulation of cell division

The maintenance of a stable internal environment despite external variations is known as:

• Adaptation

• Homeostasis

• Regulation

• Transformation

• Stabilization

The process by which sweating restores normal body temperature after overheating is an example of:

• A negative feedback mechanism

• A positive feedback mechanism

• A cyclic inhibition

• Reflex acceleration

• A feed-forward system

Oxygen molecules move from the alveoli of the lungs into pulmonary capillary blood primarily through:

• Active transport using ATP

• Facilitated diffusion

• Simple diffusion through lipid membranes

• Endocytosis

• Osmotic transport

The movement of water through a selectively permeable membrane from an area of low solute concentration to one of higher solute concentration is termed:

• Filtration

• Osmosis

• Active transport

• Facilitated diffusion

• Pinocytosis

The absorption of glucose in intestinal cells together with sodium ions utilizes the sodium gradient established by ATP, representing:

• Simple diffusion

• Primary active transport

• Secondary active transport

• Osmotic exchange

• Facilitated diffusion