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Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A): All vertebrates are chordates but all chordates are not vertebrates. Reason (R): Notochord is replaced by vertebral column in the adult vertebrates. In the light of the above statements, choose the most appropriate answer from the options given below:
Select the correct statements: A: Platyhelminthes are triploblastic, pseudocoelomate and bilaterally symmetrical organisms. B: Ctenophores reproduce only sexually and fertilization is external. C: In tapeworm, fertilization is internal but sexes are not separate. D: Ctenophores are exclusively marine, diploblastic and bioluminescent organisms. E: In sponges, fertilization is external and development is direct. Choose the correct answer from the options given below:
Match List-I with List-II List-I (A) Contractile vacuole (B) Water vascular system (C) Canal system (D) Flame cells List-II (I) Asterias (II) Amoeba (III) Spongilla (IV) Taenia Choose the correct answer from the options given below:
The unique mammalian characteristics are:
Read the following statements about the vascular bundles: (a) In roots, xylem and phloem in a vascular bundle are arranged in an alternate manner along the different radii. (b) Conjoint closed vascular bundles do not possess cambium. (c) In open vascular bundles, cambium is present in between xylem and phloem. (d) The vascular bundles of dicotyledonous stem possess endarch protoxylem. (e) In monocotyledonous root, usually there are more than six xylem bundles. Choose the correct answer from the options given below:
Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following :
In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to :
Which of the following is not a character of collenchyma tissue?
Which compound amongst the following is not an aromatic compound?
The IUPAC name of the complex $[Ag(H_2O)_2][Ag(CN)_2]$ is:
Amongst the following molecules, which one has a linear shape?
Given below are two statements : Statement I : The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole-dipole interactions. Statement II : The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of H-bonding. In the light of the above statements, choose the most appropriate answer from the given below
The given graph is a representation of kinetics of a reaction. The y and x axes for zero and first order reactions, respectively are
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from its unit cells. Reason (R): In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality. In the light of the above statements, choose the most appropriate answer from the options given below:
Which of the following sequence of reactions is suitable to synthesize chlorobenzene?
Identify the incorrect statement from the following. (1) All the five $5d$ orbitals are different in size when compared to the respective $4d$ orbitals. (2) All the five $4d$ orbitals have shapes similar to the respective $3d$ orbitals. (3) In an atom, all the five $3d$ orbitals are equal in energy in free state. The shapes of $d_{xy}$, $d_{yz}$ and $d_{zx}$ orbitals are similar to each other; and $d_{x^2-y^2}$ and $d_{z^2}$ are similar to each other.
Given below are two statements: Statement I: The boiling points of the following hydrides of group 16 elements increases in the order $H_2O
The incorrect statement regarding chirality is
The transverse section of plant part showed polyarch, radial and exarch xylem, with endodermis and pericycle. The plant part is identified as:
Given below are two statements: Statement I: In a dicotyledonous leaf, the adaxial epidermis general bears more stomata than the abaxial epidermis. Statement II: In a dicotyledonous leaf, the adaxially placed palisade parenchyma is made up of elongated cells, which are arranged vertically and parallel to each other. In light of the above statements, choose the correct answer from the options given below: