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[A]: Human ancestors never used their t...

[A]: Human ancestors never used their tails and so the tail expressing gene has disap- peared in them.
[R]: Lamarck's theory of evolution is popularly called theory of continuity of germ plasm

A

If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark a

B

lf both Assertion & Reason are true but the reason is no t the correct explanation of the assertion, then mark b

C

If Assertion is true statement but Reason is false, then mark c

D

If both Assertion and Reason are false statements, then mark d.

Text Solution

Verified by Experts

The correct Answer is:
D

If human share ancestry with other primates, then we should expect see remants of that common ancestry in our genes. For example, tails, this characteristic is still exhibited occssionally in atavishm. According to current evolutionary theory, the ancestors of human lost their tails about 25 million years ago, when apes (tail-less primates) diverged from monkeys (tailed primates). Theory of the continuity of the germplasm was given by Weismann. The German biologist Welsmann recognized that animals are made up of body cells (somaplasm), which contain gamete-producing cells (germplasm). At each generation, the embryo that develops from the zygote not only sets aside some germplasm for the next generation but also produces the cells that will develop into the body, the soma, of the organism. Jean-Baptise Lamarck (1744-1829), presented the first widely discussed theory of Evolution, the idea that organisms are connected through time by ancestor-descendent relationships and that they change through time. Lamarcks' theory of evolution had foru main components. (1) Spontaneous generation of organisms from inanimate matter occurs continuosly throughout Earth history (2) Extinction does not occur. (3) Traits developed by parents are passed on directly to offspring (The Inhertiance of Aquired Characteristics). (4) Use or disuse of parts causes them to transformation (i.e, it drove evolutionary change).
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Assertion : Human ancestors never used their tails and so the tails expressing gene has disappeared in them. Reason : Lamarck's theory of evolution is popularly called theory of continuity of germ plasm.

Assertion: Human ancestors never used their tails and so the tail-expressing gene has disappeared in them. Reason: Lamarck's theory of evolution is popularly called theory of continuity of germplasm.

Niels Bohr a Danish physicist received his PhD from the University of Copenhagen in 1911. He that spent a year with J.J. Thomson and Ernest Rutherford in England. In 1913, he returned to Copenhagen Where he remained for the rest of his life. In 1920 he was named Director of the Institute of theory! Physics After first World War Bohr worked energetically for peaceful uses of atomic energy recieved the first Atoms for Peace award in 1957 Bohr was awarded the Nobel Prize in Physics 1922 (a) The Angular momentum of an electron in a given stationary state can be expressed as m_e vr =h/(2pi) where n=1, 2,3 ...... Thus an electron can move only in those orbits for which its angular momentum is integral multiple of h/2 pi that is why only certain fixed orbits are alowed (b) The radii of the stationary states are expressed as r_n=n^2a_0 where a_0 =52.9 pm. Thus the radius the first stationary state, called the Bohr radius, is 52.9 pm. Normally the electron in the hydrogen atom is found in this orbit (that is n =1). As n increases the value of r will increase (c) The most important property associated with the electron E_n=-2.18xx10^(-18)(Z^2/n^2)J n=1,2,3 (d)it is also possible to calculate to calculate the velocities of electrons moving in these orbits by using v_n=2.18 10^6xxZ/n m/sec. Qualitatively the magnitude of velocity of electron increases with increase of positive charge on the nucleus and decreases with increases the value of n. (e)Bohr's theory can also be applied to th ions containing only one electron, similar to that present it hydrogen atom. For example , He^+ Li^(2+) , Be^(3+) and so on. given by the expression Ex=-218x n=1,2,3 (d) It is also possible to calculate the velocities of electrons moving in these orbits by using V 2.1810 cm/sec Qualitatively the magnitude of velocity of electron increases with increase of positive charge on the nucleus and decreases with increase the value of n (e) Bohr's theory can also be applied to the ions containing only one electron, similar to that presenti hydrogen atom For example, Help, Be and so on Choose the correct statement

Niels Bohr a Danish physicist received his PhD from the University of Copenhagen in 1911. He that spent a year with J.J. Thomson and Ernest Rutherford in England. In 1913, he returned to Copenhagen Where he remained for the rest of his life. In 1920 he was named Director of the Institute of theory! Physics After first World War Bohr worked energetically for peaceful uses of atomic energy recieved the first Atoms for Peace award in 1957 Bohr was awarded the Nobel Prize in Physics 1922 (a) The Angular momentum of an electron in a given stationary state can be expressed as m_e vr =h/(2pi) where n=1, 2,3 ...... Thus an electron can move only in those orbits for which its angular momentum is integral multiple of h/2 pi that is why only certain fixed orbits are alowed (b) The radii of the stationary states are expressed as r_n=n^2a_0 where a_0 =52.9 pm. Thus the radius the first stationary state, called the Bohr radius, is 52.9 pm. Normally the electron in the hydrogen atom is found in this orbit (that is n =1). As n increases the value of r will increase (c) The most important property associated with the electron E_n=-2.18xx10^(-18)(Z^2/n^2)J n=1,2,3 (d)it is also possible to calculate to calculate the velocities of electrons moving in these orbits by using v_n=2.18 10^6xxZ/n m/sec. Qualitatively the magnitude of velocity of electron increases with increase of positive charge on the nucleus and decreases with increases the value of n. (e)Bohr's theory can also be applied to th ions containing only one electron, similar to that present it hydrogen atom. For example , He^+ Li^(2+) , Be^(3+) and so on. given by the expression Ex=-218x n=1,2,3 (d) It is also possible to calculate the velocities of electrons moving in these orbits by using V 2.1810 cm/sec Qualitatively the magnitude of velocity of electron increases with increase of positive charge on the nucleus and decreases with increase the value of n (e) Bohr's theory can also be applied to the ions containing only one electron, similar to that presenti hydrogen atom For example, Help, Be and so on Choose the incorrect curve : if v=velocity of electron in Bohr's orbit r=Radius of electron in Bohr's orbit P.E.=Potential energy of electron in Bohr's orbit K.E.=Kinetic energy of the electron in Bohr's orbit.