The checkpoint in cell cycle plays important role in 

1.	repairing DNA damage
2.	apoptosis initiation
3.	assessing DNA damage
4.	none of these.

Identify the correct matched pair.

The mandatory combination responsible for assembly of microtubules are

1. $N{a}^{+}$ and $C{a}^{2+}$

2. $M{g}^{2+}$ and $C{a}^{2+}$

3. $C{l}^{-}$ and $C{a}^{2+}$

4. $N{a}^{+}$ and $K^{+}$

The exchange of segments of non-sister chromatids between chromosomes of a homologous pair termed as

(1) transformation 

(2) translocation

(3) crossing over

(4) chromosomal aberration

Which of the following ions are necessary for assembly of microtubules?

(1) $N{a}^{+}$ and ${\mathrm{K}}^{+}$

(2) ${\mathrm{Ca}}^{2+}$ and ${\mathrm{Cl}}^{-}$

(3) ${\mathrm{Ca}}^{2+}$ and ${\mathrm{Mg}}^{2+}$

(4) ${\mathrm{Na}}^{+}$ and ${\mathrm{Ca}}^{2+}$

Which one of the following is the best stage to observe the shape, size and number of chromosomes in a cell?

(1) Interphase
(2) Prophase
(3) Metaphase
(4) Telophase

Calcium dependent Kinases can control 

What is the correct sequence of the steps given here ? Also work out the process depicted in the steps.
(i) Homologous chromosomes move toward opposite poles of the cell; chromatids do not separate
(ii) Chromosomes gather together at the two poles of the cell and the nucleare membranes reform 
(iii) Homologous chromosomes pair and exchange segments 
(iv) Homologous chromosomes align on a central plate
(v) The haploid cells separate completely
1. The correct sequence is $\mathrm{III}\to \mathrm{IV}\to \mathrm{I}\to \mathrm{II}\to \mathrm{V}$ and the process is meiosis-I

2. The correct sequence is $\mathrm{II}\to \mathrm{I}\to \mathrm{V}\to \mathrm{IV}\to \mathrm{III}$ and the process is mitosis

3. The correct sequence is $\mathrm{IV}\to \mathrm{I}\to \mathrm{III}\to \mathrm{II}\to \mathrm{V}$ and the process is meiosis-I

4. the correct sequence is $\mathrm{II}\to \mathrm{V}\to \mathrm{IV}\to \mathrm{I}\to \mathrm{II}$ and the process is mitosis

During meiosis, the sister chromatids separate during:

(1) Anaphase II    

(2) Anaphase I     

(3) The S phase    

(4) Synapsis

Chromosomes decondense into diffuse chromatin:

1. At the end of telophase                

2. At the beginning of prophase

3. At the end of interphase              

4. At the end of metaphase