One difference between sieve-tube cells and vessels is that sieve-tube cells are ________, but vessels are dead.

A. hollow
B. alive
C. nucleated
D. more spherical
E. placed end to end


B. alive

Biology & Microbiology

You might also like to view...

The green algae include

a. unicellular species only. b. multicellular species only. c. unicellular and multicellular species. d. unicellular and colonial species. e. unicellular, multicellular, and colonial species.

Biology & Microbiology

When killifish were present, what was the main selection factor affecting the average number of spots on male guppies?

a. reduction in spot number to avoid predation b. increase in spot number to attract females c. both selective forces were in effect when killifish were present

Biology & Microbiology

__________ line human nasal passages. Fill in the blank(s) with the appropriate word(s)

Biology & Microbiology

Give the bird-like and reptile-like features of Archaeopteryx? What will be an ideal response?

Biology & Microbiology