MCQ: CELL REPRODUCTION

 Cell reproduction

1. The duration of the cell cycle in humans is
    a. 20 minutes
    b. 22-25 hours
    c. 20 hours 

    d. 26 hours
Answer: d, The duration of the cell cycle in humans is 26 hours.

2. Which of the following statements is true about the G1 phase?

    a. DNA content doubles in the G1 phase.

    b. There is no change in the DNA content of cells in the G1 phase.

    c. Chromatin threads are formed in the G1 phase.

    d. Cell organelles are formed in the G1 phase.

Answer:d,  Cell organelles like mitochondria, lysosome, Golgi body, and ribosomes are formed in the G1 phase.

3. DNA replication takes place in

    a. G1 phase

    b. S phase 

    c. G2 phase

    d. M phase
Answer: d, DNA replication takes place in S-phase. S-phase means the synthesis phase. M phase is characterized by actual cell division by mitosis or meiosis 

4. In which phase of the cell cycle are the proteins required for the formation of spindle fibers formed?

    a. Metaphase
    b. Prophase
    c. G2 phase 

    d. S phase 

Answer: c,  Proteins required for the formation of the spindle are formed in the G2 phase by centrioles. 

5. Cell cycle continues in
    a. meiosis
    b. mitosis
    c. Both 1 and 2
    d. Neither 1 nor 2
Answer:b,  Cell cycle does not stop in mitosis after the formation of daughter cells

6. Who used the term mitosis for the first time?

    a. Strasburger
    b. Fleming
    c. Nageli
    d. Virchow
Answer: b,  Fleming used the term mitosis for the first time for somatic cell division (1882). 

7. If one cell cycle takes 100 minutes for completion, then the time spent in M-phase is 

    a. 30 minutes 

    b. 40-minute

     c. 10 minutes 

     d. 20 minutes 

Answer:c,  10% of the time is spent in M-phase. Thus, 10 min

8. In which phase of mitosis do nucleoli and nuclear membrane disappear?
    a. Metaphase
    b. Anaphase
    c. Telophase
    d. Prophase

Answer: The nucleoli and nuclear membrane disappear in the prophase of mitosis.


9.In animal cells, astral rays in prophase emerge out from

    a. telomeres
    b. centromeres
    c.  centrioles
    d. centrosomes

Answer: In animal cells, the astral rays emerge out from centrosomes and give centrioles a star-like appearance.

10. In which phase do chromosomes start becoming visible under a light microscope?
    a. Prophase
    b. Anaphase
    c. Metaphase
    d. S-phase

Answer: a,  Chromosomes start becoming visible under a light microscope in prophase. 


11. Which is the most suitable phase for counting and identifying chromosomes? 

    a. Telophase
    b. Metaphase
    c. Anaphase
    d. Prophase

Answer: d, The metaphase stage is the most suitable phase for counting and identifying chromosomes. 

12. Why can chromosomes be best identified and counted at metaphase?

    a. Because chromosomes are arranged at the equator
    b. Because each chromosome becomes more compact and short
    c. Spindle fibers are attached at each centromere
    d. Chromosomes become thick and long

Answer: b,  Chromosomes can be identified and counted because each chromosome becomes more compact and short. 

13. In which phase of mitosis does centromere divide into two?
    a. Prophase 

    b. Metaphase 

    c. Anaphase 

    d. Telophase 

Answer: c,  In anaphase, centromeres of each chromosome divide and permit the separation of two chromatids. 

14.What happens during telophase?
    a. Nuclear membrane reappears.
    b. Chromosomes form a chromatin network.
    c. Spindle fibers disappear.
    d. All of the above

Answer: d, During telophase, nuclear membrane reappears, chromatin network is formed and spindle fibers disappear.

15. What is the chemical composition of spindle fibers? 

    a. Cellulose
    b. Proteins
    c. Pectin
    d. Lipids

Answer: Spindle fibers are composed of proteins, called microtubules. 


16. What is the number and appearance of chromosomes in the nucleus of a eukaryotic cell called?
a. Karyogram
b. Karyology
c. Karyotype 

d. Kinetochore 

Answer: c, A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell. 

17. Which human chromosome is the result of the fusion of two ancestral ape chromosomes?
    a. Chromosome X
    b. Chromosome 2
    c. Chromosome Y
    d. Chromosome 1
Answer: b, Human chromosome 2 is now known to be a result of an end-to-end fusion of two ancestral ape chromosomes. It is the second-largest human chromosome. 


18.Which stage of the cell cycle should be observed for the determination of the sex of an unborn fetus?
    a. Anaphase
    b. Prophase
    c. Metaphase
    d. Interphase

Answer: d, The sex of an unborn fetus can be determined by observation of interphase cells. DNA is in the replication stage at interphase, therefore observation of fetal DNA is very convenient.


19. Different amounts of DNA duplication could probably cause a difference in

    a. relative size of chromosomes
    b. the absolute size of chromosomes
    c. position of centromeres
    d. the basic number of chromosomes
Answer: b, Differences in the absolute size of chromosomes were probably due to different amounts of DNA duplication. 

20. The darker staining areas on G-banding are produced by
a. euchromatin
b. heterochromatin
c. centromeres
d. telomeres
Answer: b,  The dark regions on G-banding tend to be heterochromatin. 


21. By which technique of depiction of karyotypes are fluorescent patterns obtained?
1. G-banding
2. C-banding
3. Q-banding
4. R-banding
Answer: c, Q-banding is a fluorescent pattern obtained using quinacrine for staining. Quinacrin (atebrin) binds both regions rich in AT and in GC, but only the AT-quinacrin-complex fluoresces. Since regions rich in AT are more common in heterochromatin than in euchromatin, these regions are labeled preferentially. 

22. What is the ploidy in which the chromosome number in the cells is not the typical number for the species called?
    a. Endopolyploidy
    b. Haplo-diploidy
    c. Euploidy
    d. Aneuploidy
Answer: d,  The ploidy in which the chromosome number in the cells is not the typical number for the species is termed aneuploidy

23. In karyotype analysis, which stain can be used to identify Nucleolus Organiser Region (NOR)?
    a. Giemsa stain
    b. Silver stain
    c. Gentian violet stain
    d. Quinacrine
Answer: b, In karyotype analysis, a silver stain can be used to identify the NOR silver nitrate inserts into the NOR-associated protein in the stalks and satellites, staining the proteins dark black. 

24. Paratomy is a form of
    a. sexual reproduction
    b. asexual reproduction
    c. vegetative reproduction
    d. behavior in which an animal sheds or discards one or more of its own appendages
Answer: b,  Paratomy is a form of asexual reproduction in animals where the organism splits in a plane perpendicular to the anteroposterior axis and the split is preceded by the pregeneration of the anterior structures in the posterior portion. 

25. Which of the following replication processes is/are observed in Apicomplexa?
    a. Closed mitosis
    b. Shizogamy
    c. Meiosis
    d. All of these
Answer. d,  In Apicomplexa, mitosis is usually closed, with an intranuclear spindle; in some species, it is open at the poles.  In Apicomplexa, cell division is usually by schizogony, and In Apicomplexa, meiosis occurs in the zygote. 

Thus, All three replication processes are observed in Apicomplexa. 

26. Hayflick limit correlates with
    a. length of chromosomes
    b. position of centromeres
    c. length of telomeres
    d. number of divisions a cell has undergone 

Answer:  The Hayflick limit has been found to correlate with the length of the telomere region. 

27. Which of the following sentences is untrue about heterochromatin?
    a. Heterochromatins are compactly coiled regions.
    b. Heterochromatin is only found in prokaryotes.
    c. The functions of heterochromatin are gene expression, gene repression, and DNA transcription.
    d. Heterochromatin is late replicative.
Answer: b, Heterochromatins are compactly coiled regions. Heterochromatin is only found in eukaryotes.  The functions of heterochromatin are gene expression, gene repression, and DNA transcription  Heterochromatin is late replicative. 

28. Polytene chromosomes are found in
    a. oocytes of vertebrates
    b. drosophila
    c. maize plant 

    d. Hemiptera
Answer: b, Polytene chromosomes are found in drosophila. Here, the chromosome replicates several times and becomes an exceptionally giant size called polytene. Lamp-brush chromosomes are found in the oocytes of vertebrates. Maize plants have B-chromosomes. Holokinetic chromosomes are found in Hemiptera. The kinetic activity is distributed over the entire chromosome and such chromosomes are called holokinetic chromosomes 

29. What is the number of visible major chromosomal arms per set of chromosomes called?
    a. Aneuploidy
    b. Fundamental number
    c. Digital karyotyping
    d. Basic number
Answer: d,  Aneuploidy is the condition in which the chromosome number in the cells is not the typical number for the species.  The fundamental number, FN, of a karyotype is the number of visible major chromosomal arms per set of chromosomes.  Digital karyotyping is a technique used to quantify the DNA copy number on a genomic scale.  The number of visible chromosomal arms per set of chromosomes is not called the basic number. 

30. Bladder cancer is a disease related to
    a. chromosome 3
    b. chromosome 4
    c. chromosome 5
    d. chromosome 6
Answer: b, Bladder cancer is a disease related to chromosome 4. 54 cancer genes are located in this chromosome. Hereditary non-polyposis colorectal cancer and ovarian cancer are related to chromosome 3.  None of the cancers is related to chromosome 5. There are no cancer-related genes on chromosome 5 None of the cancers is related to chromosome 6 

31. S phase of the cell cycle is accompanied by:
a. Synthesis of DNA
b. Duplication of centrosome
c. Copying of organelles
d. Making molecular building blocks
1. a and b
2. a and c
3. a and d
4. c and d
Answer: 1,  In the S phase, the cell synthesizes a complete copy of the DNA in its nucleus. It also duplicates a microtubule-organizing structure called the centrosome, which helps separate DNA during the M phase.  Cell copies organelles and makes the molecular building blocks it will need in later steps in the G1 phase. 

32. In the cell cycle, damaged DNA is repaired in
    a. G0 phase
    b. G1 phase
    c. G2 phase
    d. S phase 

Answer: c, In the G2 phase, damaged DNA is repaired. The G0 phase is the 'resting phase' in the cell cycle in which cells exist in an inactive state. In the G1 phase, the cell increases in size and synthesizes rRNA, mRNA ribosomes, and proteins. In the S phase, the cell synthesizes a complete copy of the DNA in its nucleus. 

33. The cells which never enter the G0 phase are
    a. erythrocytes
    b. hepatocytes
    c. germ cells
    d. lymphocytes

Answer: c, Germ cells never enter the G0 phase. They divide rapidly with a short G1phase. Cells that never enter the G0 phase are termed labile cells. Erythrocytes permanently remain in the G0 phase. These cells do not divide they are highly specialized cells that do not regenerate if damaged. These are called permanent cells. Hepatocytes leave G0 and re-enter G1 on being stimulated by growth factors. These are stable cells. Lymphocytes leave the G0 phase and re-enter the G1 phase when stimulated by growth factors. These are stable cells. 

34. Histone production occurs maximally during
    a. M phase
    b. G1 phase
    c. G2 phase
    d. S phase

Answer: d, Maximum histone production occurs during the S phase. S phase is the one in which DNA replication occurs.  During the mitotic (M) phase, the copied DNA and cytoplasm divides to make two new cells. During the G1 phase, the biosynthetic activities of the cell are resumed at a high rate. G2 phase occurs after DNA replication and is accompanied by protein synthesis and rapid cell growth to prepare the cell for mitosis. 

35. 30-50% generation time of the cell is represented by
    a. S phase
    b. G2 phase
    c. M phase 

    d. prophase 

Answer: a, S phase represents 30-50% of the total generation time of the dividing cell. In this phase, DNA replication, histone synthesis, and the doubling of slender chromosomes take place. G2 phase represents 10-20% of the generation time of the cell. 

 M phase represents 5-10% of the generation time of the cell. Prophase takes less than 10% of the generation time of the cell. 

36. In mitosis, the spindle fibers start disappearing at
    a. metaphase
    b. anaphase
    c. prometaphase
    d. telophase

Answer: b, In anaphase of mitosis, the spindle fibers start disappearing as the chromosomes reach the poles. In Metaphase Spindle fibers are intact but the chromosomes are aligned at the equator in metaphase. In prometaphase, the nucleolus disappears and spindle formation continues.  Spindle fibers completely disappear in telophase. 

37. Degradation of structural proteins associated with the chromosomal kinetochore is promoted by 

    a. anaphase-promoting complex (APC)
    b. cyclin-dependent kinases (CDKs)
    c. G1/S cyclins
    d. p53 protein

Answer: a,  Anaphase-promoting complex (APC) promotes the degradation of structural proteins associated with the chromosomal kinetochore.  Cyclin-dependent kinases (CDKs) determine a cell's progress through the cell cycle.  G1/S cyclins move the cell from the G1 phase to the S phase.  p53 (TP5) is a gene that codes for a protein that regulates the cell cycle by binding to the tumors. 

38. Chromatin is visible under the microscope for the first time from
    a. S of interphase
    b. prometaphase
    c. G1 of interphase
    d. prophase

Answer: d, In prophase, chromatin in the nucleus begins to condense and becomes visible in the light microscope as chromosomes. : Though the chromosomes have duplicated by the S phase, still the chromatin can't be observed under a microscope in S-phase as the condensation has not taken place.  Distinct chromosomes appear in prometaphase as the chromosomes begin moving after Microtubules attach at the kinetochores.: Chromatin material is not visible in the G1 phase.

39. In mitosis, plate formation takes place in
    a. telophase
    b. anaphase
    c. metaphase
    d. prometaphase

Answer: c, In metaphase, spindle fibers line-up the chromosomes along the middle of the cell nucleus. This line is referred to as the metaphase plate. 

 In prometaphase, proteins attach to the centromeres creating the kinetochores. Microtubules attach at the kinetochores and the chromosomes begin moving. In telophase, chromatids arrive at opposite poles of the cell, and new membranes form around the daughter nuclei.  In anaphase, the paired chromosomes separate at the kinetochores and move to opposite sides of the cell.

40. Chromomeres in meiosis appear at
    a. zygotene phase
    b. leptotene phase
    c. pachytene phase
    d. diplotene phase

Answer: b, At the leptotene stage, chromatin condenses, and fine chromatin fibers appear with granule like chromomeres in them. Chromatin fibers are highly coiled at chromomeres.  Two homologous chromosomes lay side by side i.e. pairing takes place at the zygotene phase. The homologous chromosomes exchange the segments at the pachytene phase.  Bivalents move away from each other and chiasmata disappear at the diplotene phase.

41. Mitotic cycle of animals differs from that of plants as plants' mitotic cycle involves
    a. centrosomes
    b. anastral spindle
    c. mid-body
    d. centripetal cleavage

Answer: Spindle is anastral in plants, whereas it is amphiastral in animals.  Centrosomes do not occur in the mitotic cycle of the plants. Mid-body is absent in plants but it is present in animals. It is formed during cytokinesis. Cell plate grows centrifugally in plants, cleavage proceeds centripetally in animals. 

42. Gene p53, which regulates the cell cycle and functions in tumor suppression, is located on
    a. Chromosome 6
    b. Chromosome 7
    c. Chromosome 17
    d. Chromosome 16 

Answer: Gene p53 is not located on Chromosome 16. Chromosome 6 does not contain gene p53. 
Gene p53 is not located on Chromosome 7.  The human p53 gene is located on the seventeenth chromosome. This is a gene that codes for a protein that regulates the cell cycle and hence functions in tumor suppression

43. Which of the following sentences is false about meiosis?
    a. Chromosomes converge towards one side during early prophase I.
    b. The centromeres face the equator in metaphase.
    c. Chromosomes divide only once.
    d. DNA replicates once.
Answer: b,  In meiosis, chromosomes converge towards one side during early prophase I. It is known as the bouquet stage. In meiosis, the metaphase chromosomes are arranged in such a way that centromeres face poles. In meiosis, though there are two cell divisions, still the chromosomes divide only once. DNA replicates only once for two cell divisions. 

44.In meiosis, the part of the chromosome where crossing over takes place is
    a. chromomeres
    b. chiasmata
    c. telomeres
    d. centromere

Answer: b,  Crossing over takes place at chiasmata. This is the point at which members of a chromosome pair are in contact during the prophase of meiosis and because of which, recombination or crossing over occurs on separation. Chromomeres are small bead-shaped and heavily staining masses of coiled chromatin that are linearly arranged along the chromosome.: A telomere is a region of repetitive nucleotide sequences at each end of a chromosome. The part of the chromosome where sister chromatids are linked is called the centromere.

45. Cytokinesis in plants is accompanied by
    a. pinching of cell membrane
    b. division of homologous chromosomes
    c. formation of cell plate 

    d. the non-existence of metaphase plate

Answer: In cytokinesis, the spindle fibers are used to bring in vesicles that line up along the cell plate and produce a new cell wall. Cytokinesis in animal cells is accompanied by pinching of cell membranes. Mitosis in eukaryotic cells results in the equal division of all chromosomes Movement from the metaphase plate occurs during the separation of chromatids at anaphase. 

46. Equational division refers to
    a. first meiotic division
    b. second meiotic division
    c. mitotic division
    d. direct nuclear division 

Answer: b, Second meiotic division is an equational division because it does not reduce chromosome numbers. It is a nuclear division that maintains the same ploidy level of the cell.  The first meiotic division is not known as equational division because the reduction in chromosome number occurs here. The mitotic division is not referred to as equational division. Direct nuclear division is not referred to as equational division. It is a direct division of the nucleus and cell without the nuclear changes that usually occur during cell reproduction. 

47. Phase(s) of interphase is/are:
    a. Second growth phase
    b. Synthesis phase
    c. Both of the above 

    d. None of the above

Answer: c, Both the second growth phase and synthesis phase are the phases of interphase. The second subphase of the interphase is known as the second growth phase. The synthesis phase is a part of the interphase. During this phase, replication of DNA and synthesis of histones occur. 

48. Which of the following proteins is/are not synthesized in the G1 phase?
    a. Enzymes
    b. Histone proteins
    c. Regulatory proteins 
    d. Tubulin

Explanation: b, Synthesis of histone proteins occurs in S-phase to provide a new DNA with nucleosomes. Enzymes are synthesized in the G1 phase.  Regulatory proteins, which control various events of mitosis, are synthesized in the G1 phase. Tubulin is a protein synthesized in the G1 phase. It is required for the formation of the mitotic apparatus. 

49. The metaphase chromosomes in mitosis are
    a. short and thick
    b. long and thick
    c. short and thin
    d. long and thin

Answer: Chromosomes are short and thick at metaphase as each chromosome becomes more compact in this phase. Chromosomes are not long in metaphase, they are compact. Due to compactness, chromosomes are short during metaphase. Chromosomes are long and thin in prophase. 

50. Enzyme ribonuclease is a poison for 

    a. metaphase
    b. prophase
    c. anaphase
    d. interphase

Answer: b, The enzyme ribonuclease is prophase poison. A higher concentration of this poison may lead to the death of the cell. Explanation: Colchicine is a metaphase poison. It inhibits the spindle formation and holds the cell in the metaphase stage. Explanation: Enzyme ribonuclease is not an anaphase poison. Explanation: Enzyme ribonuclease is not an interphase poison. 

51. Synapses of a pair of homologous chromosomes lead to the formation of which of the following?
    a. Dyad
    b. Chiasmata
    c. Bivalent
    d. Telomere

Answer: c, The complex formed by a pair of synapsed homologous chromosomes is called as bivalent.  Dyad is a replicated chromosome having two sister chromatids. Chiasmata is the point at which the two homologous chromosomes cross. The telomere is a region of repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. 

52. In the fetal stage, the first meiotic arrest of oogenesis occurs at which of the following?
    a. Diplotene stage
    b. Diakinesis
    c. Pachytene stage 
    d. Metaphase 1

Answer: a,  The first meiotic arrest of oogenesis occurs at the diplotene stage. This resting phase lasts till puberty, during which each month till menopause, a pair of primary oocytes complete the first meiosis.  At diakinesis, first, the meiotic arrest does not occur. In fact, due to the arrest at the diplotene stage, meiosis never progresses to diakinesis in the fetal stage.  The first meiotic arrest does not occur at the pachytene stage. Metaphase 1 stage never comes in fetal oogenesis as meiosis is arrested at the diplotene stage. 

53. During the process of terminalisation in meiosis, 

    a. exchange of the segments between non-sister chromatids takes place
    b. migration of dyads to poles takes place
    c. movement of sister chromatids takes place
    d. displacement of chiasmata takes place

Answer: The displacement of chiasmata is termed as terminalisation, which is initiated in diplotene but is completed in the diakinesis stage. Exchange of the segments between non-sister chromatids is crossing over, which takes place in the pachytene stage.  At anaphase 1, the homologous dyads separate and migrate towards their respective poles. Movement of sister chromatids takes place at metaphase 1 of meiosis. 

54. Which of the following phases of meiosis does not take place in the trillium plant? 

    a. Anaphase 1
    b. Prophase 2
    c. Metaphase 2 

    d. Telophase 1

Answer: d, In the trillium plant, telophase 1 does not occur and anaphase 1 is followed by prophase 2 directly.  Explanation: In anaphase 1, the centromere divides and sister chromatids are pulled towards the poles. In the trillium plant, prophase 2 comes immediately after anaphase 1.  Daughter chromosomes are pulled towards the poles in metaphase 2 of the trillium plant. 

55. Two equatorial plates are formed by the centromeres in
    a. all metaphases
    b. metaphase 2 of meiosis 

    c. metaphase of mitosis 

    d. metaphase 1 of meiosis 

Answer: a, Two equatorial plates are formed by the centromeres in metaphase 1 of meiosis.  A single equatorial plate is formed by the centromere in metaphase 2 of meiosis as the chromosomes are not paired. One equatorial plate is formed by the centromeres in the metaphase of mitosis. Two equatorial plates are formed by centromeres in metaphase 1 of meiosis. 

56. Match the events with the stages of the cell cycle.
Events                                                                              Stage of the cell cycle
1. Chromosomes are moved to spindle equator                 a. Mitotic anaphase
2. Centromere splits and chromatids separate                    b. Meiosis I pachytene
3. Pairing between homologous chromosomes                   c. Mitotic metaphase
4. Crossing between homologous chromosomes                 d. Meiosis I zygotene

1. 1 - c, 2 - a, 3 - d, 4 - b
2. 1 - a, 2 - c, 3 - d, 4 - b 
3. 1 - c, 2 - a, 3 - b. 4 - d 
4. 1 - a, 2 - c, 3 - b, 4 - d

Answer: 1.During mitotic metaphase, chromosomes become arranged at the equator of the spindle. In the anaphase stage, the centromere of each chromosome divides and permits the separation of two sister chromatids. At the zygotene of meiosis, the two homologous chromosomes lie side by side, which is known as pairing. At the pachytene stage, crossing over between homologous chromosomes takes place. 

57. The sister chromatids are kept close together by which of the following during the formation of the synaptonemal complex?
    a. Adhesins
    b. Cohesions
    c. Motor proteins
    d. Tubulin 

Answer: b, Cohesion is required to keep the sister chromatids together until their separation at anaphase. Cohesion is created by multi-protein subunit complexes called cohesins.  During cell division, motor proteins are required for spindle formation, chromosome alignment, and segregation.  Tubulin is required for spindle formation. 

58. Pachytene phase of meiosis is characterized by which of the following? 

    a. Synapsis
    b. Crossing over
    c. Terminalisation 

    d. Astral rays 

Answer: b, Crossing over takes place in the pachytene phase of meiosis. In this process, two homologous chromosomes exchange segments. Synapsis takes place in the zygotene phase. In synapsis, the pairing of homologous chromosomes takes place  Terminalisation takes place in the diplotene phase. Each bivalent moves away from each other and chiasmata finally disappear.  Astral rays emerge out of the centriole during diakinesis. 

59. Which of the following meiosis is there in organisms having a haplontic life cycle?
    a. Zygotic meiosis
    b. Gametic meiosis
    c. Sporic meiosis
    d. Either gametic or sporic meiosis 

Answer: a, Organism having zygotic meiosis has a haplontic life cycle. Meiosis in most of the animals takes place during gametogenesis. It is termed as genetic meiosis. When two gametes fuse in fertilization, a diploid zygote is formed. Thus, gametic meiosis results in a diplontic life cycle. 

In Sporic, plant meiosis takes place in the zygote and the resulting organism is haploid In plants, meiosis generally occurs during sporogenesis. It is called sporic meiosis. Spores produce a new gametophytic phase in the life cycle. Gametes are formed by gametophytes. Because of the presence of two distinct multicellular phases, diploid and haploid, the life cycle of plant is diplohaplontic. In organisms showing a haplontic life cycle, both gametic or sporic meiosis are absent. 

60. Which of the following parts of the chromosome attaches to the spindle fiber?
    a. Telomere
    b. Kinetosome 
    c. Centrosome 
    d. Kinetochore

Answer: d,  Spindle fibers attach to kinetochore of chromosomes during cell division. They help the chromosomes to get separated to the two daughters towards opposite poles.  The telomere is a region of repetitive nucleotide sequences at each end of a chromosome, which protects the end of the chromosome from deterioration. : Kinetosome is a structure in some flagellate protozoans, which forms the base of the flagellum. Explanation: Spindle fibers do not attach to the centrosome.