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Wind pollination is common in:
Plants with ovaries having only one or a few ovules are generally pollinated by:
Double fertilization is exhibited by:
In which one of the following is pollination autogamous?
Which one of the following plants shows a very close relationship with a species of moth, where none of the two can complete its life cycle without the other?
In a flowering plant, archesporium gives rise to:
What is the function of germ pores?
Unisexuality of flowers prevents:
Match List-I with List-II. List-I: A. Coke, B. Diamond, C. Fullerene, D. Graphite. List-II: I. Carbon atoms are $sp^3$ hybridised, II. Used as a dry lubricant, III. Used as a reducing agent, IV. Cage like molecules. Choose the correct answer from the options given below:
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R: Assertion A: Metallic sodium dissolves in liquid ammonia giving a deep blue solution, which is paramagnetic. Reason R: The deep blue solution is due to the formation of amide. In the light of the above statements, choose the correct answer from the options given below:
Which of the following reactions will NOT give primary amine as the product? (1) $CH_3CONH_2 \xrightarrow{Br_2/KOH} \text{Product}$ (2) $CH_3CN \xrightarrow[\text{(ii) } H_3O^+]{\text{(i) } LiAlH_4} \text{Product}$ (3) $CH_3NC \xrightarrow[\text{(ii) } H_3O^+]{\text{(i) } LiAlH_4} \text{Product}$ (4) $CH_3CONH_2 \xrightarrow[\text{(ii) } H_3O^+]{\text{(i) } LiAlH_4} \text{Product}$
Which one is an example of heterogenous catalysis?
The conductivity of centimolar solution of KCl at $25^{\circ}\text{C}$ is $0.0210 \text{ ohm}^{-1} \text{ cm}^{-1}$ and the resistance of the cell containing the solution at $25^{\circ}\text{C}$ is $60 \text{ ohm}$. The value of cell constant is
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Helium is used to dilute oxygen in diving apparatus. Reason R : Helium has high solubility in $O_2$. In the light of the above statements, choose the correct answer from the options given below
Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : A reaction can have zero activation energy. Reasons R : The minimum extra amount of energy absorbed by reactant molecules so that their energy becomes equal to threshold value, is called activation energy. In the light of the above statements, choose the correct answer from the options given below :
In Lassaigne's extract of an organic compound, both nitrogen and sulphur are present, which gives blood red colour with $Fe^{3+}$ due to the formation of
The given compound [Diagram of a benzene ring attached to a CH2-CH=CH-CH2-CH3 chain] is an example of ________.
Identify the product in the following reaction: $C_6H_5N_2Cl \xrightarrow[(ii) Mg/dry ether]{(i) Cu_2Br_2/HBr} \xrightarrow[(iii) H_2O]{} Product$
Eight-nucleated embryosac is:
Nucellar polyembryony is reported in species of: