In which one of the following, the male and female gametophytes don’t have free-living independent existence?
Pteris
Funaria
Polytrichum
Cedrus
A.
Pteris
In Pteris (also Dryopteris), the spore germinates to produce the prothallus. The prothallus is a small, green, flat, surface loving, thallus-like object. It is monoecious and bears sex organs on the ventral side. The antheridia (male sex organs) arise among the rhizoids towards the posterior side of the prothallus and are emergent. The archegonia develop in central cushion behind the apical notch. In these plants, o male and female gametophytes do not have free-living independent existence.
All species of Polytrichum are dioecious. The antheridia and archegonia are borne on different gametophore. The plant body is an erect leafy shoot but is not the entire gametophyte.
The leafy shoot arises from protonema (the juvenile stage). The leafy gametophore of Funaria reproduces sexually by the formation of antheridia and archegonia. The antheridia are formed at the summit of a relatively small, thin, leafy shoot, which develops first. The female branch arises later as a lateral outgrowth from the base of parent male shoot.
Which of the following characteristics is are exhibited by C4 -plants?
I. Kranz anatomy.
II. The first product of photosynthesis is oxaloacetic acid.
III. Both PEP carboxylates and ribulose biphosphate carboxylate act as carboxylating enzymes.
The correct option is
I and III, but not ll
I and II, but not III
II and III, but not I
ll and III
Which of the following plant keeps its stomata open during night and closed during the day?
Orchid
Cactus
Tea
Wheat
Which of the following cell organelles is associated with photorespiration?
Mitochondria
Peroxysome
Chloroplast
All of these
The net requirement of assimilatory power for the formation of 6 hexose molecules in maize plant is
72 ATP, 48 NADPH
90 ATP, 60 NADPH
108 ATP, 72 NADPH
180 ATP, 72 NADPH
Which one of the following elements is an activator for both ribulose biphosphate, carboxylase oxygenase and phosphoenol-pyruvate carboxylase in photosynthetic carbon fixation?
Mg2+
Zn2+
Mn2+
Cl− and K+
Which of the following characteristics out of I, II and III are exhibited by C4 plants?
I. Kranz anatomy.
II. The product of photosynthesis is oxalo acetic acid.
III. Both PEP carboxylase and ribulose-bis phosphate carboxylase act as carboxylating enzyme.
Choose the correct option.
I and II, but not III
II and III, but not I
I and III, but not II
All of these
Light reaction in stroma lamellae of the chloroplast results in the formation of
NADPH
ATP + NADPH
ATP K
O2
