Bio Past exam possible questions

In insertional inactivation A) if foreign DNA is inserted, the beta galactosidase marker is inactivated, and the colonies remain white B) if foreign DNA is inserted, the beta galactosidase marker is inactivated, and the colonies turn blue C) if foreign DNA is inserted, the beta galactosidase marker is activated, and the colonies remain white D) if foreign DNA is inserted, the beta galactosidase marker is activated, and the colonies turn blue

A

Paracrine signaling A) involves secreting cells acting on nearby target cells by discharging a local regulator into the extracellular fluid. B) requires nerve cells to release a neurotransmitter into the synapse. C) occurs only in paracrine yeast cells. D) has been found in plants but not animals. E) involves mating factors attaching to target cells and causing production of new paracrine cells.

A

The lac repressor A) binds to the operator and prevents transcription B) binds to the CAP site and prevents transcription C) binds to the CAP site and facilitates transcription D) binds to the operator and facilitates transcription

A

The lac z gene marker codes for A) b galactosidase, which splits x-gal B) b galactosidase, which makes x-gal resistant to splitting C) ampicillin resistance D) white colonies

A

DNA replication begins at a specific site called the A) initiator B) start codon C) origin D) promoter E) replicator

C

Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells? A) peroxisomes B) desmosomes C) gap junctions D) extracellular matrix E) tight junctions

C

This is the shortest part of the cell cycle: A) G0 B) G1 C) S D) G2 E) M

E

One DNA strand is used as the template to make two new strands of DNA. A) True B) False

False

) Early 19th-century scientists believed that living organisms differed from nonliving things as a result of possessing aȱȈlife forceȈȱthat could create organic molecules from inorganic matter. The term given to this belief is A) organic synthesis. B) vitalism. C) mechanism. D) organic evolution. E) inorganic synthesis.

B

During aerobic respiration, electrons travel downhill in which sequence? A) food citric acid cycle ATP NAD+ B) food NADH electron transport chain oxygen C) glucose pyruvate ATP oxygen D) glucose ATP electron transport chain NADH E) food glycolysis citric acid cycle NADH ATP

B

If host cells are ampicillin sensitive and are plated on a medium containing ampicillin A) only cells that have not taken up the ampicillin resistant vector can grow B) only cells that have taken up the ampicillin resistant vector can grow C) all cells will grow D) ampicillin is inactivated

B

In DNA replication A) both strands replicate in the same direction B) each strand replicates in a different direction C) only one strand of DNA is used as a template D) a single strand of DNA is copied to make two single strands of DNA

B

White blood cells engulf bacteria through what process? A) exocytosis B) phagocytosis C) pinocytosis D) osmosis E) receptor-mediated exocytosis

B

What is the reducing agent in the following reaction? Pyruvate + NADH + H+ Lactate + NAD+

B NADH

Which of the following is most similar in structure to ATP? A) an anabolic steroid B) a DNA helix C) an RNA nucleotide D) an amino acid with three phosphate groups attached E) a phospholipid

C

Semiconservative replication of DNA means A) only one strand is used as a template B) a double-stranded DNA is split into two single-stranded DNAs C) only half the genes are copied into the new cells D) each DNA made contains one old strand and one new strand of DNA

D

When both glucose and lactose are present A) cyclic AMP is high so transcription occurs B) the lac repressor binds with the lactose and transcription occurs C) RNA polymerase is able to bind to the operator so transcription occurs D) transcription is turned off

D

When glucose is present A) cyclic AMP is high, the catabolite activator protein (CAP) binds to the activator binding site, and transcription of lactose is turned on B) cyclic AMP is low, CAP binds to the site activator binding site, and transcription of lactose is turned on C) cyclic AMP is high, CAP does not bind to the activator binding site, and transcription of lactose is turned on D) cyclic AMP is low, CAP does not bind to the activator binding site, and transcription is turned off

D

When both glucose and lactose are absent, transcription occurs. A) True B) False

False

When foreign DNA and plasmid are both cut with the same restriction enzyme and mixed together, all molecules will form recombinants. A) True B) False

False

After DNA replication two identical DNA molecules are formed. A) True B) False

True

In the absence of glucose, when lactose is present it combines with the repressor, allowing RNA polymerase to carry on transcription. A) True B) False

True

When beta galactosidase cleaves x-gal, white colonies result. A) True B) False

True