Cell Cycle and Cell division- Live session- NEET 2020Contact Number: 8527521718Cell Cycle and Cell division- Live session- NEET 2020Contact Number: 8527521718Bacterium divides every 35 minutes. If a culture containing 105 cells per mL is grown for 175 minutes, what will be the cell concentration per mL after 175 minutes?
1. 5 x 105 cells
2. 35 x 105 cells
3. 32 x 105 cells
4. 174 x 105 cells
What would be the number of chromosomes of the aleurone cells of a plant with 42 chromosomes in its roots tip cells?
1. 21 2. 42
3. 63 4. 84
During mitosis ER and nucleolus begin to disappear at
1. late prophase
2. early metaphase
3. late metaphase
4. early prophase
Mitotic anaphase differs from metaphase in possessing
1. same number of chromosomes and same number of chromatids
2. half number of chromosomes and half number of chromatids
3. half number of chromosomes and same number of chromatids
4. same number fo chromosomes and half number of chromatids
Meiosis I :
1. is always followed by interphase
2. is not followed by any period of rest
3. is followed by period of interkinesis
4. is sometimes followed by interphase
Bivalent chromosomes calearly appear as tetrads during :
1. Zygotene
2. Pachytene
3. Diplotene
4. Diakinesis
How do cells at the completion of meiosis compare with cells that have repliacted their DNA and are just about to begin meiosis?
1. They have twice the amount of cytoplasm and half the amount of dNA
2. They have the half number of chromosomes and half the amount of DNA
3. They have the same number of chromosomes and half the amount of DNA
4. They have the half the number of chromosomes and one-fourth the amount of DNA
The cell shown in the given diagram is in :
1. Early prophase
2. Late prophase
3. Metaphase
4. Telophase
When a cell stops growing due to shortage of nurtrients, this will occur in which phase of the cell cycle?
1. G0
2. G1
3. S
4. G2
DNA replication in bacteria occurs
1. during S-phase
2. within nucleolus
3. prior to fission
4. just before transcription
When cell has stalled DNA replication fork, which checkpoint should be predominantly activated ?
1. G1/s
2. G2/M
3. M
4. Both G2/M and M
The chromosomes in which centromere is situated close to one end are
1. metacentric
2. acrocentric
3. telocentric
4. sub-metacentric
A somatic cell that has just completed the S-phase of its cell cycle, as compared to gamete of the same species has
1. twice the number of chromosomes and twice the amount of DNA
2. same number of chromosomes by twice the amount of DNA
3. twice the number of chromosomes and fout times the amount of DNA
4. four times the number of chromosomes and twice the amount of DNA
During which phase(s) of cell cycle, amount of DNA in a cell remains at 4C level if the initial amount is denoted as 2C?
1. G0 and G1
2. G1 and S
3. Only G2
4. G2 and M
During mitosis ER and nucelolus begin to disappear at
1. late prophase
2. early metaphase
3. late metaphase
4. early prophase
The drug colchicines, used to obtain polyploidy cells, acts on the cytoskeletal structures of the plant cells called
1. microtubules
2. actin filaments
3. intermediate filaments
4. all of the above
Number of mitotic division required in a cell of root tip for formation of 128 cells is
1. 12
2. 3
3. 7
4. 6
Barr body is found in the cytoplasm during
1. interphase in cell of female mammal
2. interphase in cell of male mammal
3. prophase in cell of female mammal
4. prophase in cell of male mammal
Many cells function properly and divide mitotically even though they do not have
1. Plasma membrane
2. Cytoskeleton
3. Mitochondria
4. Plastids
Which of the following statements is incorrect about G0 phase
1. Mitosis occurs after G0 phase
2. Biocatalysts can be used to exit G0 phase
3. Cell volume keeps on increasing during this phase
4. Cell metabolism occurs continuously in G0 phase
Beads on string like structures of A are seen in B, which further condense to form chromosomes in C stage of cell division.
|
A |
B |
C |
|
|
1. |
Chromonema |
Chromatin |
Metaphase |
|
2. |
Chromatin |
Chromatid |
Metaphase |
|
3. |
Chromonema |
Chromosome |
Anaphase |
|
4. |
Chromonema |
Chromatid |
Anaphase |
The checkpoint in cell cycle plays important role in
1. repair DNA damage
2. apoptosis initiation
3. assess DNA damage
4. inhibit cell damage
The exchange of segments of two non-homologous pair fo chromosomes is termed as
1. Crossing over
2. Linkage
3. transformation
4. translocation
The total DNA content of each daughter cell is reduced during meiosis because :
1. Chromosomes do not replicate during the interphase preceding meiosis I
2. Chromosomes do not replicate between meiosis I and II
3. Half of the chromosomes from each gamete are lost during fertilization
4. Chromosomes arms are lost during crossing over
Caclium dependent Kinases can control
1. cell cycle activities
2. DNA replication
3. Cell surface receptors
4. membrane structure
Select the wrong statement :
1. Cell growth is a continuous process
2, Cytoplasmic content increase occurs only during one specific stage in the cell cycle
3. DNA synthesis occurs only during one specific phase of cell cycle
4. None of these
Which one is correct for Go stage?
I. It is a quiescent stage
II. In this phase cell cycle is stipped
III. G0 cell in this stage do not grow or proliferate but metabolically active
IV. G0 cells can divide in response to some stimulus
1. All are correct
2. I,II,III are correct
3. I,II are correct
4. Only I and IV are correct
Which of the following statements is false ?
1. Mitosis or the equational division is usually restricted to the 2N cells only
2. in onion 2N=16
3. Growth and reproduction are characteristics of cells indeed of all living organisms
4. In plants meristematic tissues show meiosis
At metaphase of mitosis, each chromosome consists of ___chromatid(s)___centromere(s)____ kinetochore(s) and ____molecules of DNA:
1. 2,1,2,2
2. 2,2,2,2
3. 2,1,1,1
4. 2,1,2,1
Which event is not associated with prophase I?
1. Synizesis
2. Synapsis
3. Segregation
4. Terminilization
Synaptonemal complex is more conspicious at :
1. Zygotene
2. Pachytene
3. Diplotene
4. Leptotene
Centrosomes are :
1. Constricted regions of chromosomes
2. Regions where microtubules polymerise
3. Part of Cilia
4. The central part of the same cell
The members of a homologous pair of chromosomes
1. Are identical in size and appearance
2. Contain indentical genetic information
3. Separate to opposite poles of the cell during mitosis
4. Are found only in haploid cells
At which stage of meiosis does the genetic constitution of gametes is finally decides :
1. Metaphase I
2. Anaphase II
3. Metaphase II
4. Anaphase I
If a yeast cell is grown for 540 minutes in a Cell culture, how many cycles of division can be expected in that time ?
1. 9
2. 6
3. 3
4. 63
If a person forgets to take the reading of his cell culture data now he needs to conclude among the two plates A(with 16 cells) and B(with 128 cells)
If these plates A and B happen to be of human cells, then plate A is of
1. 96 hrs
2. 105 hrs
3. 72 hrs
4. Both A and B
What will be the amount of DNA content before S phase
1. C
2. 2C
3. 3C
4. Can be any amount
The duplication in S phase and has started moving towards opposite poles in Prophase, we are talking about which cell component ?
1. DNA
2. Microbodies
3. Centriole
4. Nuclear envelope
Kinetochores are not
1. Formed by spindle fibres
2. Formed by asters
3. Help in attachment of chromosomes to the spindle fibres
4. Large disc-shaped structure
Mitosis doesn't perform which of the following functions ?
1. Cell repair
2. Growth of multicellular animals
3. Restoration of nucleolus cytoplasmic ratio
4. Continuation of cell growth
Recombination completion leads to
1. Chromosomes attached to each other at centromere
2. Chromosomes attached to each other at sites of crossing over in the sister chromatids
3. Chromosomes linked at the sites of crossing over
4. Both A and C
Chromosomes are fully condensed and the meiotic spindle is assembled to prepare the homologous chromosomes for separation. This is a characteristic feature of which of the following option
1. Diplotene
2. Diakinesis
3. Prophase
4. Metaphase
What does result in dyad of cells?
1. Telophase II
2. Telophase I
3. Cytokinesis I
4. Meiosis II
When does Prophase II start usually ?
1. Chromosomes are fully elongated
2. Before chromosomes are fully condensed
3. Before chromosomes are fully elongated
4. After chromosomes are fully elongated
Tetrad of cells is a result of
1. Meiosis I
2. Meiosis II
3. Mitosis
4. Prophase II
Fruit flies have a diploid number of chromosomes of eight, how many chromosomes will be there in the tetrada of cells ?
1. 4
2. 8
3. 16
4. Both A and B
Which of the following events occurs in the end, in Meiosis ?
1. Terminalisation
2. Crossing over
3. Disjunction
4. Synapsis
If at the end of meiosis a cell has 12 chromosomes, then how many chromosomes will be there in G2 phase ?
1. 12
2. 24
3. 6
4. Cannot be predicted
What will be the number of kinetochore in 2 bivalents ?
1. 4
2. 2
3. 1
4. 8
What will be the number of centromeres in two tetrads ?
1. 4
2. 2
3. 8
4. 6
