Which one is a wrong statement about sieve tubes?
i) They are found in pteridophytes and gymnosperms.
ii) They have companion cells.
iii) Sieve areas do not form sieve plates.
iv) Sieve areas are not well differentiated.
v) They consist of vertical cells placed one above the other forming long tubes connected at the end walls by sieve pores.
A(i), (ii) and (iii)
B(i), (iii) and (iv)
C(ii) and (iv)
D(v) only
Related Questions:
The seed dispersal is of compensatory zoochory in:
(i) Achyranthes
(ii) Cleome
(iii) Medicago
(iv) Mulberry
(v) Peepal
(vi) Tribulus
Choose the correct answer.
(i) Companion cells are nucleated cells of phloem.
(ii) Vessels contain only living cells.
(iii) Sieve cells are enucleated at maturity.
(iv) Abnormal secondary growth due to accessory cambia is found in Asparagus.
(v) Stone cells does not contain end walls.
Match the following and choose the correct answer.
a) S Cycle | i) Nuclear fallout |
b) Oxygen tank | ii) National Park |
c) Torrey canyon | iii) Thunder dragon |
d) Sr 90 | iv) Beggiatoa |
v) Oil spillage |
