In which stage of the cell cycle will RNA polymerase enzyme be most active ?
RNA polymerase is needed for protein synthesis which happens during G2 phase.
Cytokinesis refers to
The process of division of cytoplasm is called Cytokinesis.
Replication of centriole occurs during
It occurs during S phase of Interphase.
The sequence of cell cycle is
The cell cycle goes trough G1 , S, G2 and then mitosis or M phase.
Which Phase lasts for the maximum duration in cell cycle?
Interphase lasts for 95% of the duration of the cell cycle.
Each chromosome in the beginning of Prophase of mitosis is
Chromosomes are seen to be composed of 2 chromatids attached together at the centromere during Prophase of mitosis.
During Anaphase of mitosis, the position of the centromere is
During Anaphase of mitosis, the centromeres are arranged towards the poles of the cell.
During Anaphase of mitosis , the position of the arms of the chromatids are.
During Anaphase of mitosis the arms of the chromatids trail behind pointing to the equator.
Which part of the cell disappears during mitosis?
The nucleolus along with the nuclear membrane disappears.
Number of mitotic divisions needed to produce 64 cells from a single cell are
Each cell divides to produce two daughter cells and hence at the end of 6 mitotic divisions 32 cells will be produced(2,4,8,16,32 and 64 ).
Nuclear membrane reappears in
The nuclear envelope reappears during Telophase.
The incorrect statement for the significance of mitosis is
Mitosis retains the the same chromosome number, so the statement D is wrong, chromosome number reduced half occurs in meiosis. As the cell grows the surface-volume ratio is disturbed which is restored by mitosis, it is an equational division and it maintains the nucleoplasmic index of the cell.
In plant cells cytokinesis takes place by
In plants cytokinesis takes place by cell plate formation which is laid down at the middle and then grows to the sides. Furrow formation is seen in animals. The furrow deepens and meets in the centre dividing the cell cytoplasm into two.
The cell plate formed during cytokinesis in plants forms
The cell plate goes on to form the middle lamellae of the new plant cell. The cell wall and the secondary cell wall form over this lamella .The cell membrane is internal to the middle lamella.
Which of the statements is true for mitosis?
In mitosis first karyokinesis takes place and after this cytokinesis occurs resulting in the formation of two daughter cells.
The endosperm of coconut is an example of
The endosperm of the coconut is formed as cytokinesis does not follow karyokinesis. It is an example of a multinucleate cell.
Which of the following processes is not due to mitosis?
Growth, repair and secondary growth are all functions of mitosis. Pollen grains are formed by meiosis.
Which of the following statement is incorrect about meiosis?
Meiosis is reductional division. The other options are all true for meiosis.
Which of the following occurs only in meiosis?
Pairing of homologous chromosomes occurs only in meiosis. The other processes are common to both mitosis and meiosis.
Exchange of chromosome segments between maternal and paternal chromatids during meiosis is called.
Exchange of genetic material is called crossing over. Linkage is the process by which certain traits are inherited together. Diakinesis is a stage in prophase-1,while dominance is the property by which one gene suppresses the action of another gene.
Synapsis is seen during
The characteristic events of each stage is as follows Leptotene-compaction of chromosomes. Pachytene -crossing over. Zygotene -synapsis. Diplotene -formation of chiasmata. Diakinesis -Terminalisation of chaismata.
Crossing over results in
New gene combinations are produced as a result of croosing over. Mutations are sudden changes in genes, sex determination is because of X and Y chromosomes. Crossing over does not increase the number of chromosomes.
The nucleolus completely disappears in
The complete disappearance of the nucleolus and the breakdown of the nuclear membrane takes place in the last stage of Prophase I , i.e. Diakinesis.
Types of division which occur in Meiosis I and Meiosis II respectively are
Meiosis I is reductional division as it reduces chromosomes to half (involves separation of homologous chromosomes) whereas Meisois II is equational division(involves separation of chromatids just like mitosis). Hence the correct option is B
The phase between Meiosis I and Meiosis II is called
The phase between Meiosis I and Meiosis II is called Interkinesis. There are no phases like Interphase I and Interphase II. Interkinesis follows Telophase I. Hence the sequence is Meiosis I-Interkinesis-Meiosis II.
Necessity of Meiosis II is
As a result of meiosis 4 haploid gametes are produced after each meiosis (meiosis is reductional division and produces daughter cells with half the number of chromosomes).It does not increase the number of chromosomes or cells in an organism. It produces haploid and not diploid cells.
Genetic crossing over takes place in
Genetic crossing over takes place in Prophase I of Meiosis I. In Meiosis II or Mitosis there is no crossing over.
Complete process of Meiosis involves
Each meiosis involves Two cytokinesis(one after Telophase I and the second after Telophase II) and one process of DNA duplication during Prophase I.
The somatic cell in humans has 46 chromosomes. How many chromosomes will be present in the female gamete?
Gametes are produced by the process of meiosis which are having half the number of chromosomes as that in the somatic cells. Therefore the gametes will have 46 divided by 2=23 chromosomes.
Share your Results: