AP BIOLOGY CELLS

Prokaryotes are classified as belonging to two different domains. What are they?

• Bacteria & Protista

• Bacteria & Archaea

• Bacteria & Eukarya

• Archaea & Protista

Plant cells have ___ for cell to cell communication.

• gap junctions

• plasmodesmata

• desmosomes

• tight junctions

Which structure is common to plant and animal cells?

• central vacuole

• chloroplast

• wall made of cellulose

• mitochondrion

Which of the following is major cause of the size limits for certain types of cells?

• evolutionary progression in cell size; more primitive cells have smaller sizes.

• the need for sufficient surface area to support the cell's metabolic needs.

• limitation on the strength and integrity of the plasma membrane as cell size increases

• the difference in plasma membranes between prokaryotes and eukaryotes

White blood cells engulf bacteria through what process?

• pinocytosis

• osmosis

• phagocytosis

• exocytosis

A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively,

• mitochondria and chloroplasts.

• peroxisomes and chloroplasts.

• chloroplasts and peroxisomes.

• chloroplasts and mitochondria.

Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?

• glycogen

• cellulose

• proteins

• lipids

All of the following are part of a prokaryotic cell except

• a plasma membrane

• DNA

• an endoplasmic reticulum

• ribosomes

Which temperature and pH profile curves on the graphs were most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?

• curves 2 & 5

• curves 1 & 5

• curves 1 & 4

• curves 2 & 4

Cells tend to be small, with sizes ranging between 1 and 100 mm. These small sizes help to ensure that cells have a favorable surface-area-to-volume ratio. Choose the statement that explains why a favorable surface-area-to-volume ratio is advantageous.

• Higher surface-area-to-volume ratios improve the efficiency of transporting materials in and out of cells.

• Lower surface-area-to-volume ratios improve the efficiency of transporting materials in and our of cells.

• Higher surface-area-to-volume ratios speed up the flow of cytoplasm within cells.

• Higher surface-area-to-volume ratios slow down the flow of cytoplasm within cells.