Spindle fibers attach to kinetochores of chromosomes during

In a species, the weight of newborn ranges from \(2\) to \(5\; \mathrm{kg} .97 \%\) of the newbom with an average weight between \(3\) to \(3.3\; \mathrm{kg}\) survive whereas \(99 \%\) of the infants born with weights from \(2\) to \(2.5\; \mathrm{kg}\) or \(4.5\) to \(5 \;kg\) die. Which type of selection process is taking place?

Choose the correct statements regarding cell organelles and their inclusions.
A. The endomembrane system includes Golgi complex, endoplasmic reticulum and mitochondria.
B. Rough endoplasmic reticulum bears ribosomes on its surface.
C. Both mitochondria and plastids have circular DNA.
D. A network of microtubules, microfilaments and intermediate filaments present in the cytoplasm is called cytoskeleton.
E. Mitochondrion is a single membrane-bound structure.
Choose the correct answer from the options given below :

Which of the following are required for the dark reaction of photosynthesis? \(A\). Light  \(B\). Chlorophyll  \(C\). \(\mathrm{CO}_2\)  \(D\). \(ATP\)   \(E\). \(NADPH\) Choose the correct answer from the options given below:

Which of the following animals is not vivipa rous?

The blue and white selectable markers have been developed which differentiate recombinant colonies from non-recombinant colonies on the basis of their ability to produce colour in the presence of a chromogenic substrate.

Given below are two statements about this method:
Statement I : The blue coloured colonies have DNA insert in the plasmid and they are identified as recombinant colonies.

Statement II : The colonies without blue colour have DNA insert in the plasmid and are identified as recombinant colonies.

In the light of the above statements, choose the most appropriate answer from the options given below:

From the statements given below choose the correct option :
A. The eukaryotic ribosomes are 80S and prokaryotic ribosomes are 70S.
B. Each ribosome has two sub-units.
C. The two sub-units of 80S ribosome are 60S and 40S while that of 70S are 50S and 30S .
D. The two sub-units of 80S ribosome are 60S and 20S and that of 70S are 50S and 20S .
E. The two sub-units of 80S are 60S and 30S and that of 70S are 50S and 30S .

If the critical angle for total internal reflection from a medium to vacuum is \(45^{\circ}\), then velocity of light in the medium is,

A disc of radius \(2\; \mathrm{m}\) and mass \(100\; \mathrm{kg}\) rolls on a horizontal floor. Its centre of mass has speed of \(20\; \mathrm{cm} / \mathrm{s} .\) How much work is needed to stop it?

Match the following \(RNA\) polymerase with their transcribed products

\((a) \;RNA\) polymerase \(I\)	\((i) \;tRNA\)
\((b) \;RNA\) polymerase \(II \)	\((ii)\; rRNA\)
\((c)\; RNA\) polymerase \(III \)	\((iii) \;hnRNA\)

Select the correct option from the following

Match List \(I\) with List \(II\)

List \(I\)	List \(II\)
\(A\). Robert May	\(1\). Species-Area relationship
\(B\). Alexander von Humboldt	\(II\). Long term ecosystem experiment using out door plots
\(C\). Paul Ehrlich	\(III\). Global species diversity at about \(7\) million
\(D\). David Tilman	\(IV\). Rivet popper hypothesis

Choose the correct answer from the options given below:

The ratio of coulomb's electrostatic force to the gravitational force between an electron and a proton separated by some distance is \(2.4 \times 10^{39}\). The ratio of the proportionality constant, \(K=\frac{1}{4 \pi \varepsilon_0}\) to the Gravitational constant \(G\) is nearly (Given that the charge of the proton and electron each \(=1.6 \times 10^{-19}\; C\), the mass of the electron \(=9.11 \times 10^{-31}\; kg\), the mass of the proton \(=1.67 \times 10^{-27}\,kg\) ):

The stability of \(Cu ^{2+}\) is more than \(Cu ^{+}\)salts in aqueous solution due to -