Topoisomerase II catalyzes the transient breaking and rejoining of two strands of duplex DNA which allows the strands to pass through one another, thus altering the topology of DNA.

Sea stars possess strands of tissue that encircle the mouth and run into the arms; these strands of tissue make up the ( ) system. A: hemal B: secretory C: skeletal D: muscular E: excretory

To have highlights on the hair" means "To get strands of hair bleached." (   )

Arole-playsessionisparticularlyusefulinbringingtogetherdifferent______ofteaching. A: cords B: fibres C: threads D: strands

Comprehension, production, acquisition and practice are the major strands of psycholinguistic research.

Which<br/>one can separate the parental DNA strands? A: DnaC B: DNA-pol C: topoisomerase D: primase E: helicase

15. There was a man standing outside one of the ________ at the fair encouraging people to buy his products. A: stalls B: boots C: strands D: strolls

DNA replication, one of the new strands will grow continuously, it is<br/>called () A: Continuous strand B: Faster strand C: Leading strand D: Lagging strand

Many strands, typically 4 or 5 but as many as 10 or more, can come together in β sheets. Such β sheets can be like what?（） A: Antiparallel B: Parallel C: Mixed D: None

The<br/>actions of alkylating agents:( ) A: are<br/>cell-cycle dependent B: Cause<br/>cross-linking of DNA strands C: Inhibit<br/>DNA synthesis D: Inhibit<br/>protein synthesis