Question 1

The correct sequence of adult cell cycle phases is __________.

Accepted Answer

The cell cycle is divided into two basic phases: Interphase and M Phase (Mitosis phase). Interphase is further divided into three phases: G1 phase (Gap 1): The cell is metabolically active and continuously grows but does not replicate its DNA. S phase (Synthesis): DNA replication takes place. G2 phase (Gap 2): Proteins are synthesised in preparation for mitosis while cell growth continues. Following interphase, the cell enters the M phase where actual cell division occurs. Therefore, the correct

Question 2

Match List I with List II : List I (Phase of cell cycle) List II (Activity) A. G_1 phase I. Actual cell division occurs B. S phase II. Cell is metabolically active and continuously grows but does not

Accepted Answer

In the G_1 phase, the cell is metabolically active and continuously grows but does not replicate its DNA. In the S phase (synthesis phase), DNA replication takes place and the amount of DNA per cell doubles. In the G_2 phase, proteins are synthesized in preparation for mitosis while cell growth continues. In the M phase, actual cell division or mitosis occurs. Therefore, the correct matching is A-II, B-III, C-IV, D-I. Answer: A-II, B-III, C-IV, D-I

Question 3

Given below are two statements : Statement I : Chromosomes are fully condensed at the end of prophase I. Statement II : Meiosis I resembles mitosis. In the light of the above statements, choose the mo

Accepted Answer

According to the NCERT, diakinesis is the final stage of meiotic prophase I. During this phase, the chromosomes are fully condensed and the meiotic spindle is assembled to prepare the homologous chromosomes for separation. Thus, Statement I is correct. Meiosis II is initiated immediately after cytokinesis. In contrast to meiosis I, meiosis II resembles a normal mitosis because it involves the separation of sister chromatids. Meiosis I is a reductional division where homologous chromosomes separa

Question 4

What is the main function of the spindle fibers during mitosis?

Accepted Answer

During mitosis, spindle fibre get attach to the kinetochores of the chromosome and help in the separation of the chromosome.

Question 5

Match List-I with List-II. array |l|l|r|l| & array l List-I \ Event array & & array l List-II \ Stage of Prophase-I (Meiosis-I) array \ A. & Chiasmata formation & I. & Pachytene \ B. & Crossing ov

Accepted Answer

Zygotene is the second stage of prophase I during this stage synaptonemal complex formation occur. In pachytene the four chromatids of each bivalent chromosomes becomes distinct and clearly appears as tetrad and in this stage crossing over occurs. Diplotene is recognised by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other except at the sites of crossovers. These X-shaped are called chiasmata. Diakin

Question 6

Match List-I with List-II array |l|l|l|l| & List-I & & List-II \ A. & Cells are metabolically active and proliferate & I. & G _2 phase \ B. & DNA replication takes place & II. & G _1 phase \ C. & P

Accepted Answer

(1) During G _1 phase the cell is metabolically active and continuously grows but does not replicate its DNA. (2) S or synthesis phase marks the period during which DNA synthesis or replication takes place. (3) During the G _2 phase, proteins are synthesized in preparation for mitosis while cell growth continues. (4) Cells that do not divide further exit G _1 phase to enter an inactive stage called quiescent stage ( G _0 ) of the cell cycle. Cells in this stage remain metabolically active but no

Question 7

Recombination between homologous chromosomes is completed by the end of

Accepted Answer

Recombination between homologous chromosomes is completed by the end of pachytene.

Question 8

Given below are two statements: Statement I : Chromosomes become gradually visible under light microscope during leptotene stage. Statement II : The beginning of diplotene stage is recognized by disso

Accepted Answer

- During leptotene stage the chromosomes become gradually visible under the light microscope. - The beginning of diplotene is recognised by the dissolution of the synaptonemal complex and the tendency of the recombined homologous chromosomes of the bivalents to separate from each other except at the site of crossover. Thus both statement I and II are correct.

Question 9

Match List I with List II : Choose the correct answer from the options given below

Accepted Answer

(A) Diakinesis - Completion of terminalisation of chiasmata (B) Pachytene - Appearance of recombination nodules (C) Zygotene - Synaptonemal complex formation (D) Leptotene - Chromosomes look like thin threads A-II, B-IV, C-I, D-III

Question 10

Following are the stages of cell division : A. Gap 2 phase B. Cytokinesis C. Synthesis phase D. Karyokinesis E. Gap 1 phase Choose the correct sequence of stages from the options given below :

Accepted Answer

The correct sequence of stages of cell division is The correct sequence will be E C A D B

Question 11

Spindle fibers attach to kinetochores of chromosomes during

Accepted Answer

Spindle fibers attach to kinetochores of chromosome in metaphase stage.

Cell Cycle and Cell Division — Previous Year Questions & Solutions