Mitosis - NEET Biology Class 11 Free MCQ Test with solutions

• At the beginning of the final stage of mitosis, i.e., telophase, the chromosomes that have reached their respective poles decondense and lose their individuality.
• The individual chromosomes can no longer be seen and chromatin material tends to collect in a mass in the two poles.
• This is the stage which shows the following key events-
• Chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements.

Prophase is the initial and longest phase of mitosis. During prophase, chromatin condenses into visible chromosomes, the nuclear envelope disintegrates, and the mitotic spindle forms. This phase is crucial as it prepares the cell for the subsequent steps of mitosis, ensuring proper chromosome alignment and segregation. This phase separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells.

Hence, the correct option is B.

• Metaphase proceeds prophase and is marked by the movement of chromosomes towards the equator of cell mediated by kinetochore microtubules of spindle fibres. Alignment of chromosomes on the equatorial plane of the spindle, the metaphase plate, marks the end of metaphase.
  
• Prophase is the stage of mitosis, which is characterized by spindle formation, shortening and thickening of chromosomes, the disintegration of the nuclear envelope and disappearance of the nucleolus.
• Anaphase is the stage of mitosis which is characterized by separation of sister chromatids followed by their movement towards the opposite pole of the spindle.
• Completion of separation of sister chromatids, which are now present at the opposite poles of cell marks telophase. The cell resumes the interphase state during telophase.

Hence, the correct option is A.

NCERT Reference: Topic “Metaphase” of chapter of "Cell cycle and Cell division" of NCERT.

Mitosis is a process of nuclear division in eukaryotic cells that occurs when a parent cell divides to produce two identical daughter cells. 
Hence the process of the division will be:
► 1 cell gives 2 daughter cells (1st mitosis)
► 2 cells give 4 daughter cells (2nd mitosis)
► 4 cells give 8 daughter cells (3rd mitosis)
► 8 cells give 16 daughter cells (4th mitosis)
► 16 cells give 32 daughter cells (5th mitosis)
► 32 cells give 64 daughter cells (6th mitosis)
► 64 cells give 128 daughter cells (7th mitosis)

Hence 7 mitotic divisions cell needed for a single cell to make 128 cells.

Hence, the correct option is A.

NOTE: This question is based on basic understanding of topic Mitosis

• The centromere is the part of the chromosomes where the two sister chromatids are attached. It is required for movement of chromosomes towards poles.
  
• During mitosis, spindle fibres attach to the centromere via the kinetochore. Their physical role is to act as the site of assembly of the kinetochore - a highly complex multiprotein structure that is responsible for the actual events of chromosome segregation i.e., binding microtubules and signalling to the cell cycle machinery when all chromosomes have adopted correct attachments to the spindle so that it is safe for cell division to proceed to completion and for cells to enter anaphase.

Hence, the correct option is C.
NCERT Reference: Topic “Prophase” of chapter of "Cell cycle and Cell division" of NCERT.

Both the assertion and reason are true. Cytokinesis indeed divides the cell's cytoplasm, resulting in two daughter cells. The reason is also true as, in plant cells, cytokinesis occurs through the formation of a cell plate, which eventually develops into the cell wall separating the two daughter cells. However, the reason is not the correct explanation of the assertion because cytokinesis can occur by different mechanisms in different organisms (e.g., cleavage furrow in animal cells).

• Asters are made out of microtubules, which are a type of cytoskeletal proteins of the cell.
• Asters radiate from centrosomes on the opposite poles of the cells during the M phase of cell division.
  

Hence, the correct option is A.

NCERT Reference: Topic “Prophase” of chapter "Cell cycle and Cell division" of NCERT.

• Cytokinesis is the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells.
• Cytoplasmic division begins during or after the late stages of nuclear division in mitosis and meiosis.
• During cytokinesis, the spindle apparatus partitions and transports duplicated chromatids into the cytoplasm of the separating daughter cells.
• Followed by division of cytoplasm (cytokinesis), thus forming two daughter cells. Cytokinesis may occur by cell furrow method and cell plate method.
• It thereby ensures that chromosome number and complement are maintained from one generation to the next and that, except in special cases, the daughter cells will be functional copies of the parent cell. After the completion of the telophase and cytokinesis, each daughter cell enters the interphase of the cell cycle.

Hence, the correct option is A.
NCERT Reference: Topic "Cytokinesis” of chapter  "Cell cycle and Cell division" of NCERT.

• The mitosis division is the equatorial division which takes place in the cells which are not taking part in the reproduction.
• The cells after the division form 2 daughter cells which are identical to the mother cell in every aspect. 
• This type of division takes place in each and every organ of the body except for the formation of gametes. For example, mature cells of organs, wear and tear of the cells of epithelium, etc. 
• The genetic material of the cells is doubled during the S phase of the cell cycle where the genetic material is replicated. So that the genetic material can be equally divided between the 2 daughter cells. 

Hence, the correct option is D
NCERT Reference: Topic "M PHASE” of chapter "Cell cycle and Cell division" of NCERT.

• In Fig.A Chromatids are moving to opposite poles i.e Late anaphase.
• In Fig.B The duplicated DNA is compactly packed into chromosomes and spindle formation occurs i.e prophase.

Hence, the correct option is B.
NCERT Reference: Topic "Prophase” and “Anaphase” of chapter "Cell cycle and Cell division" of NCERT.