Consider the following nuclear reaction ${}^{238}U\longrightarrow{}^{234}Th+{}^{4}He$. Take masses of ${}^{238}U$, ${}^{234}Th$ and ${}^{4}He$ as 238.050 u, 234.043 u and 4.003 u, respectively. The Q value for the reaction, in keV, is: [Given: $1~u=931.5~MeV~c^{-2}$]

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Abingdon tortoise in Galapagos islands became extinct within a decade after goats were introduced. Reason R: Goats were more efficient at browsing than Abingdon tortoise. In the light of the above statements, choose the most appropriate answer from the options given below:

Which of the following statements about the reabsorption process in Henle's loop are correct? (a) The descending limb of Henle's loop is permeable to water but almost impermeable to electrolytes. (b) Urine gets concentrated in Henle's loop. (c) Reabsorption of $Na^{+}$ and water takes place in Henle's loop. (d) Active or passive transport of electrolytes occurs in the ascending limb of Henle's loop. Choose the correct answer from the options given below:

Given below are two statements: Statement I: When any plane passing through the central axis of the body divides the organism into two identical halves, it is called radial symmetry. Statement II: In phylum Echinodermata, both adults and larvae are radially symmetrical. In the light of the above statements, choose the most appropriate answer from the options given below:

Given below are two statements: Statement I: Chromosomes are fully condensed at the end of prophase I. Statement II: Meiosis I resembles mitosis. In the light of the above statements, choose the most appropriate answer from the options given below: