KEYSTONE PREP #4

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

The enzyme pepsin is found in the stomach. Which medicine is most likely to directly interfere with pepsin’s function?

• a medicine that affects pH

• a medicine that prevents clotting

• a medicine that blocks neural impulses

• a medicine that lowers cholesterol levels

Which process uses the products of photosynthesis as reactants?

• active transport

• cellular respiration

• DNA replication

• protein synthesis

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 transport

• correcting errors in the process of building a new cell

Which statement best describes the process by which the millions of body cells that form a housefly can all contain the same genetic information?

• Original DNA is duplicated during replication and then distributed into two new cells.

• Original RNA is duplicated during replication and then distributed into two new cells.

• Original DNA is duplicated during replication and then distributed into four new cells.

• Original RNA is duplicated during replication and then distributed into four new cells.

Which statement is true for all prokaryotic and eukaryotic organisms?

• Both types of organisms transform energy from sunlight into chemical energy.

• Both types of organisms assemble proteins through transcription and translation.

• Both types of organisms are made of cells, tissues, and organs that work together.

• Both types of organisms have DNA contained within a nucleus as genetic material.

Use the graph to answer the question.

The graph represents the number of light brown and dark brown organisms living on the bottom of a clear, sandy lake 20 years ago. Over time, the lake bottom has become covered with dark sand and sediment. Which change has most likely occurred in the population?

• The number of light-brown individuals increased.

• The number of dark-brown individuals increased.

• The number of light-brown and dark-brown individuals increased.

• The number of light-brown and dark-brown individuals became equal.

Which statement describes how a mutation would most likely affect a population?

• Genotypic variation will increase in the population.

• Genotypic variation will decrease in the population.

• The occurrence of a preexisting gene will increase in the population.

• The occurrence of a preexisting gene will decrease in the population.

Strep throat is a common human illness often caused by the bacterium Streptococcus pyogenes. Which term best classifies the colonies of Streptococcus pyogenes in a person with strep throat?

• a population

• an organelle

• a community

• an ecosystem

Which statement best describes a contribution that decomposers make to an ecosystem?

• They reduce the atomic mass of carbon atoms.

• They increase the recycling of carbon-containing molecules.

• They reduce the total number of carbon atoms in the atmosphere.

• They increase the total number of carbon nuclei within the atoms.