Which one of the following plant hormones use the two-component histidine kinase receptor system for signal transduction?

• Auxin

• Gibberellin

• Cytokinin

• Abscisic acid

122.

Rhizobial genes that participate in legume nodule formation are called nodulation (nod) genes. The nod D-encoded protein

• is an acetyltransferase that adds a fatty acyl chain to the Nod factor.

• binds to the nod box and induces transcription of all nod genes.

• catalyzes the linkage of N-acetyl glucosamine residues.

• influences the host specificity of Rhizobium.

Which one of the following statements is WRONG?

• The megasporocyte develops within the megasporangium of the ovule.

• Megasporocyte undergoes meiosis to produce four haploid megaspores.

• All the four megaspores undergo several mitotic divisions to form female gametophyte in most angiosperms.

• Female gametophyte is haploid.

Which one of the following compounds is NOT a part of alkaloid class of secondary metabolites?

• Lignin

• Indole

• Tropane

• Pyrrolidine

Which one of the following plant derived signalling molecules induces hyphal branching of arbuscular mycorrhizal fungi, a phenomenon that is observed at the initial stages of colonization by these fungi?

• Salicylic acid

• Abscisic acid

• Strigolactones

• Systemin

Which of the following is NOT true for monocots?

• Sieve tube members with companion cells.

• Vasculature atactostelic

• Tricolpate pollen

• Vascular cambium absent

In photosynthetic electron transport, electrons travel through carriers organized in the 'Z-scheme'. The following are indicated as directions of electron flow:

A. P680 → PQ_A → PQ_B → Cytb₆f → Pheo → PC → P700

B. P700 → A₀ → A₁ → FeS_x → FeS_A → Fd

C. P680 → Pheo → PQ_A → PQ_B → Cytb₆f → PC → P700

D. P700 → A₁ → A₀ → FeS_B → FeS_A → FeS_X → Fd

Which one of the following combinations is correct?

• A and B

• B and C

• C and D

• A and D

The C₄ carbon cycle is a CO₂concentrating mechanism evolved to reduce photorespiration. The following are stated as important features of the C₄ pathway:

A. The leaves of C₄ plants have Kranz anatomy that distinguishes mesophyll and bundle sheath cells.

B. In the peripheral mesophyll cells, atmospheric CO₂ is fixed by phosphoenol pyruvate carboxylase yielding a four-carbon acid.

C. In the inner layer of mesophyll, NAD-malic enzyme decarboxylase four-carbon acid and releases CO₂.

D. CO₂ is again re-fixed though Calvin cycle in the bundle sheath cells.

Which one of the following combinations is correct?

• B, C, and D

• A, B, and C

• A, B, and D

• A, C, and D

Read the following statements related to plant-pathogen interaction.

A. Systemic acquired resistance is observed following infection by compatible pathogen.

B. Induced systemic resistance is activated following infection by compatible pathogen.

C. A bacterial infection can induce effector triggered immunity (ETI) leading to hypersensitive response locally.

D. NPR1 monomers that are released in cytosol due to salicylic acid accumulation is rapidly translocated to nucleus.

Which combination of above statements is correct?

• A, B, and C

• A, C, and D

• A, B, and D

• B, C, and D

Given below are statements describing various features of solute transport and photoassimilate translocation in plants.

A. Apoplastic phloem loading of sucrose happens between cells with no plasmodesmatal connections.

B. Growing vegetative sinks (e.g. young leaves and roots) usually undergo symplastic phloem unloading.

C. Movement of water between the phloem and xylem occurs in the absence of plasmodesmatal connections.

Select the option that given a combination of correct statements:

• Only A and C

• Only B and C

• Only B and D

• Only A and B