Which structure prevents blood flowing back into the atria during ventricular contractions?

A. semilunar valves
B. atrioventricular valves
C. sinoatrial node
D. carotid blood shunts
E. foramen ovale


B. atrioventricular valves

Biology & Microbiology

You might also like to view...

Considering the catabolite repression mechanism, which observation would make you suspect it is NOT occurring?

A) CRP bound to promoter sites B) elevated levels of transcripts for maltose and sucrose catabolism C) relatively low intracellular cyclic AMP levels D) RNA polymerase bound to biosynthetic promoter sequences

Biology & Microbiology

The challenges in movement experienced by people with Parkinson disease are due to loss of dopamine-secreting neurons in the

A. medulla oblongata. B. cerebellum. C. thalamus. D. substantia nigra. E. somatosensory cortex.

Biology & Microbiology

In monocots, flower parts are typically in ____ or multiples of ____

a. threes; fours b. fours; fives c. threes, threes d. twos; twos e. fours; fours

Biology & Microbiology

Genetically modified (GM) salmon have now been approved for sale in the United States. What environmental concern has been expressed about these salmon? What is being considered to reduce this risk?

What will be an ideal response?

Biology & Microbiology