Tag: need of family planning

Questions Related to need of family planning

Which cellular organelles are involved in initration of intrinsic pathway of apoptosis?

  1. ER

  2. lysosme

  3. mitochondria

  4. All of the above


Correct Option: D
Explanation:

The death of cells which occurs as a normal and controlled part of an organism's growth or development is called apoptosis. In this endoplasmic reticulum, lysosome, mitochondria, Golgi complex are involved.

So, the correct option is ‘ER, lysosome, mitochondria’. 

Which represents the correct sequence of stages in the cell cycle?

  1. $G _1$ ,$G _2$, S,M

  2. $G _1$, $G _2$,M,S

  3. $G _1$ ,M, $G _2$,S

  4. $G _1$ , S, $G _2$,M


Correct Option: D
Explanation:

The cell progresses through defined phases of the cell cycle during its division.

first, the G1 in which some organelles starts their duplication then comes S phase where DNA has doubled then G2 phase and finally the M phase. 
So the correct sequence is 'G1,S,G2,M'.

The cell is not allowed to past the cell cycle restriction point, DNA damage is detected. Which of the following proteins are involved in detection of DNA damage and inhibition of cycle at the restriction point?

  1. Replication protein A (RPA)

  2. ATM (ataxia telangiectasia mutated ) protein

  3. Cyclin D

  4. PSS


Correct Option: A
Explanation:

A. Replication protein (RPA) - is the major protein that binds to single-stranded DNA (ssDNA) in eukaryotic cells. ... During DNA replication, RPA prevents single-stranded DNA (ssDNA) from winding back on itself or from forming secondary structures.

B. ATM (ataxia telangiectasia mutated ) protein

 It activates checkpoint signalling upon genotoxic stresses such as ionizing radiation (IR), ultraviolet light (UV), or DNA replication stalling, thereby acting as a DNA damage sensor.

C.Cyclin D - a member of the cyclin protein family that is involved in regulating cell cycle progression. 

D.PSS - an autoimmune disease of the connective tissue. It is characterized by thickening of the skin caused by the accumulation of collagen, and by injuries to small arteries.

So, the correct option is ‘Replication protein A (RPA)’.

In order to enter cell cycle a cell must be stimulated from outside. What type of molecule provides this stimulation?

  1. cyclin

  2. colk

  3. cytokines and growth factor

  4. tyrosine kinases


Correct Option: A
Explanation:

  • Cyclin-dependent kinases, through phosphorylation,  signal the cell that it is ready to pass into the next stage of the cell cycle. As their name suggests, Cyclin-Dependent Protein Kinases are dependent on cyclins, another class of regulatory proteins. Cyclins bind to Cdks, activating the Cdks to phosphorylate other molecules.

So, the correct option is 'cyclin'.

Select the correct option:

A cell cycle includes

  1. Interphase and M phase

  2. Prophase, metaphase, anaphase and telophase

  3. $G _1$, S and $G _2$ phases

  4. Karyokinesis and cytokinesis


Correct Option: A
Explanation:

The cell cycle starts from interphase . Interphase is the phase in the cell cycle that prepare a cell and its nucleus for division. It has three stages- $G _1,S $ and $G _2$.M- phase is the final phase of cell cycle..It represent the phase of actual division. It consists of karyokinesis (division of nucleus ) and cytokinesis (division of cell protoplast).

Select the correct option:

Which one is the correct sequence of a cell cycle?

  1. $G _2 \rightarrow M \rightarrow G _1 \rightarrow S$

  2. $S \rightarrow G _2 \rightarrow M \rightarrow G _1$

  3. $G _1 \rightarrow S \rightarrow G _2 \rightarrow M$

  4. $M \rightarrow G _1 \rightarrow S \rightarrow G _2$


Correct Option: C
Explanation:

The cell cycle starts from interphase . Interphase is the phase in the cell cycle that prepare a cell and its nucleus for division. It has three stages- $G _1,S $ and $G _2$.M- phase is the final phase of cell cycle..It represent the phase of actual division. It consists of karyokinesis (division of nucleus ) and cytokinesis (division of cell protoplast).

So, the correct answer is 'G1→S→G2→M'.

Select the correct option:

Synthesis of histone proteins occurs in 

  1. $G _1$ phase

  2. Interphase

  3. Anaphase

  4. $G _0$ phase


Correct Option: B
Explanation:

The cell cycle is a sequence of event which occurs during cell growth and cell division. It has two phases; interphase and the M phase. Interphase is the period between the end of 1 division and the beginning of next cell division. It is also known as resting phase or the non-dividing stage.

It has three phases G₁ phase which is the post-mitotic phase, the synthetic phase which is the S phase and the G₂ phase. During the S phase, DNA replication takes place and the amount becomes double. Here the synthesis of histone protein and non-histone chromosomal proteins also takes place.
So, the correct option is 'Interphase'

Human cells in culture show a cell cycle to be completed in approximately 
  1. 42 hours

  2. 24 hours

  3. 24 minutes

  4. 24 seconds


Correct Option: B
Explanation:

Cell division is the process by which a cell divides to form to nearly equal daughter cell which resembles the parent. The cell cycle is the sequence of events which occur during the cell growth and cell division. It is completed into two steps interphase and M-phase.

In the cell cycle interphase is the period between the end of one division to the beginning of next cell division. It is known as the resting phase. In the case of human beings it is around 24 hours then the M phase takes place.

So, the correct option is '24 hours'

________ is characterised by all the chromosomes coming to lie at the equator, with one chromatid connected by its kinetochore to spindle fibres from one pole and its sister chromatid connected by its kinetochore to spindle fibres from the opposite pole.
  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase


Correct Option: B
Explanation:

During the cellular division phase, metaphase is a stage where all the chromosome arranges themselves on the metaphase plate.

On this equatorial plate, these are aligned and appear as two threaded chromosomes. These are attached to the pole by spindle fibre.
So, the correct option is 'Metaphase'