Pre Medical Exam PMT Foundation – Cell Cycle and Cell Division
Multiple Choice Questions
l. Find the correctly matched pairs and choose the correct option
I. Leptone – The chromosomes become invisible.
II. Zygotene – Pairing of homologous chromosomes.
III. Pachytene – Dissolution of the synaptonemal complex takes place.
IV. Diplotene – Bivalent chromosomes appear as tetrads.
V. Diakinesis – Terminalisation of chiasmata takes place.
(a) I and II (b) II and IV
(c) II and V (d) II and III
2. Identify the following figures (A-D) and choose the correct option.
(a) A – Metaphase – II, B – Anaphase -1, C – Prophase-I, D – Anaphase – II
(b) A – Prophase -1, B – Anaphase -1, C – Interphase, D – Metaphase -1
(c) A – Metaphase -1, B – Anaphase -1, C – Prophase-I, D – Anaphase – II
(d) A – Prophase – II, B – Anaphase -1, C – Interphase, D – Metaphase – II
3. Select the correct option with respect to mitosis.
(a) Chromatids start moving towards opposite poles in telophase.
(b) Golgi complex and endoplasmic reticulum are still visible at the end of prophase.
(c) Chromosomes move to the spindle equator and get aligned along equatorial plate in metaphase.
(d) Chromatids separate but remain in the centre of the cell in anaphase.
4. What is the number of mitotic cell divisions required to produce 256 cells from a single cell?
(a) 10 (b) 12
(c) 6 (d) 8
5. Consider the following statements about plant cytokinesis.
I. It usually occurs by cell plate method.
II. The spindle usually persists during cytokinesis.
III. Cell plate grows centrifugally.
6. Which of the statements given above are correct? (a) I and II (b) I and III
(c) II and III (d) I, II and III
7. Match the following columns.
|B.||Histone synthesis||(ii)||Anaphase -1|
|D.||Interkinesis||(iv)||Meiosis – II|
|E.||Double equatorial plate||(v)||G1-phase|
8. From the following, identify the two correct statements with reference to meiosis.
I. Bead like structures are absent on chromosome.
II. Displacement of chaismata occurs in diakinesis.
III. Separation of two basic sets of chromosomes.
IV. No division of centromere.
9. Choose the correct answer for the statements given below.
(a) II, III (b) II, IV (c) III, IV (d) I, III ^9. Choose the correct answer for the statements given
I. Protein involved in the shortening and thickening of chromosome fibres.
II. The name of early prophase when elongated chromosomes occur in overlapped condition like a ball of wool without their ends being visible.
III. Each group of astral rays along with its centriole pair.
IV. The narrow point which is responsible for attaching two sister chromatids to each other.
(a) I – Condensins, II – Aster, Ill-Spireme stage, IV-Kinetochore
(b) I – Condensins, II – Aster, Ill-Spireme stage, IV-Centromere
(c) I – Condensins, ll-Spireme stage, III – Aster, IV-Centromere
(d) I – Tubulins, ll-Spireme stage, III – Aster, IV-Centromere.
10. Match the following columns.
|A.||Chromosomes in matching pairs||(i)||Metaphase plate|
|B.||In mitosis, each chromosome is copied||(ii)||Homologous|
|C.||Precursor for cell wall formation that represents the middle wall of two adjacent cells is called||(iii)||Cell plate|
|D.||The plane of alignment of the chromosomes at equator of the cell is referred to as the||(iv)||Cell divides to give two daughter cells|
11. Identify A-C in the given statements, and choose the correct option.
I. Spindle microtubules that extend from the two poles of a dividing cell are called A
II. A centromere connects two identical copies of a single chromosome. These two copies are called C
III. In ‘X’ phase, the paired chromosomes separate and begin moving to opposite ends of the cells. This ‘X’ is called
(a) A – kinetochore fibres; B- chromatids, C-metaphase
(b) A-polar fibers, B-homologous chromosomes; C-prophase.
(c) A – polar fibres, B-sister chromatids; C- anaphase
(d) A – kinetochore fibres; B-asters; C-anaphase. fel2 . Cell would normally proceed to mitosis without interruption.
(a) Once it had started the S period
(b) Once it had entered the G2-phase
(c) at anytime during cell division
(d) None of the above.
13- Meiosis in a plant cell occurs when there is a change from
(a) gametophyte to sporophyte
(b) sporophyte to gametophyte
(c) gametophyte to gametophyte
(d) sporophyte to sporopyte.
14. If we ignore the effect of crossing over, how many different haploid cells arise by meiosis in a diploid cell having 2n = 12?
(a) 8 (b) 16
(c) 32 (d) 64
fel5. Identify A-D to complete the given statements (l-lll).
I. Phase of cell cycle are controlled by proteins, A_ and B.
II. There are two regulatory mechanisms, called C
which take decision about cell division.
III. The second check point, called D is responsible for transition from G2 to M-phase.
(a) A -cyclins; B- CdKs; C- check points, D – mitotic cydin (Cm)
(b) A – cyclins; B – checkpoints, C-mitotic cydin, D – CdKs
(c) A – mitotic cydin (Cm), B – CdKs; C – checkpoints, D- Cydin
(d) A – mitotic cydin (Cm), B – cyclins, C – check points; D – CdKs.
True or False questions
16. Spindle is formed inside the nucleus in eumitosis, which is observed in many protists, fungi and algae.
17. In an aster, the microtubular astral rays are connected to centrioles.
18. Chiasmata between homologous chromosomes of bivalents are observed during pachytene, soon after crossing over.
19. Dissimilar chromosomes move towards opposite poles in anaphase I while the chromatids move towards opposite poles in anaphase II.
20. Cytokinesis follows immediately after mitosis and meiosis I.
21. G0 is also called anaphase, in which the cell stores energy as ATP for completion of cell division later.
22. The chromosomes replicate prior to meiosis I and meiosis II.
23. If the amount of DNA in a non-dividing cell of an organism is y, then the DNA in the same cell at anaphase I will also be y.
24. During anaphase, a diploid (2n) cell from the pancreas of a frog will be tetraploid (4n).
25. Homologous chromosomes have the same length of DNA, banding pattern, genes and alleles.
Match The Columns
26. Match Column-I with Column-II
|D.||Anaphase I||(iv)||Mid body|
27. Match Column-1 with Column-ll.There may be more than one correct matches for items in Column-1.
|B.||Direct cell division||(ii)||Prophase II|
|D.||Anaphase I||(iv)||Energy stage|
Passage Based Questions
28.(A) Complete the given passage with appropriate words or phrases.
During (i) stage, the chromosomes become compact and are visible under the light microscope. This is followed by the next stage called (ii) . during which chromosomes start pairing by a process called (iii) . Electron micrographs of this stage indicate the formation of a complex structure called (iv) . This complex is formed by a pair of homologous chromosomes and is called (v) or (vi) .
(B) Read the passage and correct the errors wherever present.
(i) The beginning of diakinesis is recognized by the association of the synaptonemal complex.
(ii) During G2 phase DNA remains same, but chromosome number doubles.
(iii) Cells that do not divide further, remain in inactive G1 stage.
Assertion & Reasoning questions
In each of the following questions, a statement of Assertion is given and a corresponding statement of Reason is given just below it. Of the statements, mark the correct answer as:
(a) if both A and R are true and R is the correct explanation of A
(b) if both A and R are true but R is not the correct explanation of A
(c) if A is true but R is false
(d) if both A and R are false.
29. Assertion : Gametic meiosis occurs in diplohaplontic life cycle.
Reason: The diploid sporophyte forms gametes which undergo meiosis, thereby forming haploid gametes.
30. Assertion : Meiosis II is similar to mitosis as it is a homotypic division.
Reason : There is no reduction in chromosome number.
31. Assertion : Disjunction refers to the separation of homologous chromosomes.
Reason : It occurs during anaphase, anaphase I and anaphase II.
32. Assertion : The daughter chromosomes remain connected to each other by the tractile fibrils. Reason : The tractile fibrils extend between the daughter chromosomes.
33. Assertion : Cytokinesis does not always follow karyokinesis.
Reason : It results in a multinudeate condition called coenocyte or synctium.
34. Assertion : Cancer of the scrotum is due to uncontrolled meiotic divisions.
Reason : Gametes are produced by mitosis in the testes present in the scrotum.
35. Assertion : Mitosis produces multicellular condition that provides opportunity for differentiation.
Reason : It results in variations which are the driving force for evolution.
36. Assertion: A genome consists of chromosomes which are represented singly.
Reason: A diploid cell has 46 genomes, while haploid cell has 23.
37. Assertion : The check points C0 and Cw regulate interphase during G, and G2 of meiosis only.
Reason : They represent the deciding factor based on the availability of mitogens only.
38. Assertion : Human nerve cells do not divide after birth.
Reason : The interphase period of human nerve cells lasts throughout the life of a person.
Figure Based Questions
39. Refer to the figure given below and identify P, Q, R, S.
40. Refer to the given figure and complete the blank spaces with the appropriate words/letters.
(a) (i)contains multienzyme complex called (ii).
(b) (iii) enzyme develops breaks in individual chromatids by a process called (iv).
(c) Enzyme (v) develops gaps in individual chromatids, while (vi) enzyme helps in the separation of the segments.
(d) (vii) is the process by which the separated chromatid segments get reunited by the enzyme called (viii).
I. (c) 2. (b) 3. (c) 4. (d) 5. (d)
6. (d) 7. (c) 8. (d) 9. (c) 10. (a)
II. (c) 12. (a) 13. (b) 14. (d) 15. (a)
16. False. Spindle is formed inside the nucleus in premitosis or intranuclear mitosis.
17. False. They are connected to pericentriolar satellites.
18. False. Chiasmata are observed during diplotene, diakinesis and metaphase-l
19. False. Dissimilar chromosomes move towards the opposite poles both in anaphase I and anaphase II.
20. False. Cytokinesis follows every mitosis, but not always after meiosis I.
21. False. Gt is called antephase.
22. False. The chromosomes replicate only once, prior to meiosis I.
23. False. The amount of DNA will be 2y, as the cell has undergone replication during interphase.
25. False. They will not have the same alleles; rest everything will be the same.
26. A-(vii), B-(iii), C-(iv), D-(i), E-(v), F-(ii), G-(vi)
27. A-(iv, xiii), B-(vii, xiv), C-(ii, xi), D-(i, x), E-(v, viii), F-(iii, xii), G-(vi, ix)
28. (A) (i) leptotene, (ii) zygotene, (iii) synapsis, (iv)
synaptonemal complex, (v) bivalent, (vi) tetrad.
(B) (i) The begining of diakinesis diplotene is recognized by the association dissolution of the synaptonemal complex.
(ii) During S phase DNA chromosome number remains same, but ehremosome number DNA doubles.
(iii) Cells that do not divide further, remain in inactive &, G0 stage.
29. (d) 30. (b) 31. (c) 32. (d) 33. (b)
34. (d) 35. (c) 36. (d) 37. (d) 38. (a)
39. P – Central element Q – Chromatid
R – Lateral element S – Recombination nodule.
40. (a) (i) S; (ii) Recombinase;
(b) (iii) Endonuclease; (iv) nicking;
(c) (v) Exonuclease, (vi) Unwindase or U-protein;
(d) (vii) Re-annealing, (viii) R – protein.