Keystone Review #5B

Carbon can combine with many different elements but frequently combines with oxygen, hydrogen, and nitrogen to form organic molecules. Which statement best explains why carbon is able to form a large number of different molecules?

• carbon forms only ionic bonds

• carbon can form only ring structures

• carbon can form four covalent bonds

• carbon forms small, simple structures

A group of students is given a sample of an unknown substance. The students are asked to gather evidence to determine whether the substance is living or nonliving. The students take a small sample of the substance and observe it using a microscope. What are two characteristics of the substance that could be observed to indicate whether it is living or nonliving.

• the substance is made up of cells

• the substance responds to stimuli

• the substance is made up of carbon atoms

• the substance is green

Which structure and function are common to all plants and some protists and distinguish them from all animals?

• chloroplasts that conduct photosynthesis

• mitochondria that conduct photosynthesis

• chloroplasts that conduct cellular respiration

• mitochondria that conduct cellular respiration

Cellulose is a carbohydrate and a polymer of glucose. Which statement best describes how cellulose is formed within living organisms?

• It is assembled by bonding individual atoms.

• It is constructed by connecting smaller monomer subunits.

• It is the product of the decomposition of a much larger molecule.

• It is the result of a physical change that alters the shape of a compound.

Which transport mechanisms require the formation of a vesicle to transport material into or out of a cell?

• diffusion and osmosis

• exocytosis and endocytosis

• exocytosis and calcium pumps

• diffusion and facilitated diffusion

The Golgi apparatus is broken down during mitosis and then reformed. Which function would a cell be unable to perform during the time that its Golgi apparatus is broken down?

• copying genetic material to include in the new cell

• forming vesicles to import molecules into the cell

• processing and packaging proteins for cellular export

• correcting errors in the process of building a new cell

Molecules Needed for Protein Synthesis include

• mRNA • tRNA • amino acids • ATP molecules

A plant cell uses the molecules in the list to synthesize a protein. What role do the ATP molecules play in the protein synthesis process?

• they provide energy

• they increase activation energy

• they convert energy into hereditary information

• they absorb excess energy to prevent overheating

Which statement correctly describes how a protein is formed?

• a monosaccharide bonded to a side chain is broken apart

• amino acids are bonded together in a long chain to form a new molecule

• a molecule containing glycerol bonded to three fatty acids is broken apart

• a nitrogenous base, a sugar, and a phosphate group combine to form a new molecule

Which action is prevented by the plasma membrane?

• the flow of light into or out of the cell

• the flow of oxygen into or out of the cell

• unlimited flow of heat into or out of the cell

• unlimited flow of water into or out of the cell

In a Biological Reaction, tyrosine + valine + proline----> tyrosine, valine, proline bonded together by peptide bonds. Which statement best describes this event?

• Glucose is being synthesized in the chloroplast using nitrogen from plants.

• Amino acid monomers are joining together to form a protein macromolecule.

• A polymer in the nucleus is being broken into its individual monomer subunits.

• Lipid molecules are forming fatty acid chains in a dehydration synthesis reaction.