Biology Keystone Prep 1

A certain type of epithelial tissue consists of layers of cells tightly bound together. This tissue lacks blood vessels and has a high rate of cell replacement. Which statement describes the most likely function of this tissue in the human body?

• It allows for movement of limbs
• It provides cushioning to internal organs.
• It provides physical protection against injury.
• It transports various nutrients throughout the body

The plasma membrane of a eukaryotic cell has many transmembrane proteins that cross the lipid bilayer. Which statement best describes the function of these proteins in the plasma membrane?

• They create a rigid barrier for the cell.
• They make the membrane impermeable to water.
• They transport undigested material to the outside of the cell.
• They provide channels of movement for some ions and molecules.

Which list of events occurs during the interphase stage of the cell cycle?

• chromosomes align at the center of the cell, spindle fibers shorten, and chromatids begin moving to cell poles
• chromatids arrive at opposite poles of cell, new membranes form around daughter nuclei, and chromosomes disperse
•  DNA replicates, centrioles divide, and proteins are actively produced
•  cytoplasm divides and a contractile ring separates cell into two daughter cells

A bacterial cell is a prokaryote, while the protist euglena is a eukaryote. Which structure is present in both organisms?

•  a nucleus that controls the actions of the cell
• a mitochondria that provides the cell with energy
•  a cell wall that maintains a rigid structure for the cell
• a cell membrane that holds in the contents of the cell

Proteins are very important in the structure and function of living things and are synthesized within the cell. Which cell structure is responsible for reading the DNA instructions in the cytoplasm and assembling the proteins?

• Nucleus
• Ribosomes
• Golgi Body
• Endoplasmic Reticulum

Fish, frogs, and plankton are some organisms found in a pond. Which characteristic do fish, frogs, and plankton have in common?

• They live only in water.
• They make their own food.
• They require energy to live.
• They breathe air through their gills.

Of the elements commonly found in biological molecules, which is capable of forming the greatest number of covalent bonds?

• carbon
• hydrogen
• nitrogen
• oxygen

Which of the following best describes one function of chloroplasts in a plant cell?

• storage of wastes
• capture of solar energy
• regulation of water transport
• release of energy from carbohydrates

Digestive activity in the stomach occurs at an acidic pH of 2. Which statement best explains the role that pH has in digestion?

• The acidic pH presents the substrate to the digestive juices.
• The acidic pH facilitates the absorption of food within the stomach.
• The acidic pH protects the stomach lining from the digestive juices
• The acidic pH alters the active sites of the enzymes in the stomach.

Most anabolic reactions, such as fat and polysaccharide synthesis, require energy to build macromolecules. Which source provides the usable form of energy to the cell for these reactions?

• ATP
• DNA
• glucose
• sunlight