Select the best option from the following statements.
(a)Vitamin A derivatives are formed from carotene.
(b)The photopigments are embedded in the membrane discs of the inner segment
(c)Retinal is a derivative of Vitamin A
(d)Retinal is a light absorbing part of all the visual photopigments.
- (a), (c) and (d)
- (b), (c) and (d)
- (a) and (b)
- (a) and (c)
Function of companion cells is:
Providing energy to sieve elements for active transport.
Loading of sucrose into sieve elements by passive transport.
Providing water to phloem.
Loading of sucrose into sieve elementsby active transport.
- both b & c
- trace elements
- Sodium, hydrogen, selenium and cobalt
- Carbon, hydrogen, oxygen and nitrogen
- Magnesium, manganese, molybdenum and nickel
- Zinc, boron, iron and copper