Tag: component of the cell
Questions Related to component of the cell
Yeast complete cell cycle in _____________.
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30 minutes
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60 minutes
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90 minutes
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120 minutes
One cell cycle of yeast is almost 90 minutes and a human cell takes almost 24 hours to divide by mitosis therefore by calculations it seems that a yeast can perform mitosis almost 16 times in the time of 1 division of a human cell.
Cell cycle was discovered by
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Farmer and Moore
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Prevost and Dumas
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Howard and Pelc
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Remak
In a culture of E.coli the cell population increased from $1.5 \times 10^6$ cells /ml to $ 12 \times 10^6$ cells/ml in 36 minute.The generation time is
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6 mt
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9 mt
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12 mt
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18 mt
At the start, the culture of E. coli has cell population of 1.5 X 10$^6$ cells/ml. After first generation, it will be doubled, that is 3 X 10$^6$ cells/ml. After second generation, it will be 6 X 10$^6$ cells/ml. After third generation, it will be 12 X 10$^6$ cells/ ml. It is given that for a cell population to increase from 1. 5 X 10$^6$ cells/ml to 12 X 10$^6$ cells/ml, it takes 36 minutes. It means, for 3 generation, it takes 36 minutes. So, its generation time is 36/3 = 12.
Cdk which control progression through cell cycle check points are fully activated by.
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Binding to cyclin
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Phosphorylation by Cdk activating protein kinase
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Binding to cyclin, plus phosphorylation by Cdk activating protein kinase
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Phosphorylation by tyrosine kinase
Through phosphorylation, Cdks signal the cell that it is ready to pass into the next stage of the cell cycle. As their name suggests, Cyclin-Dependent ProteinKinases are dependent on cyclins, another class of regulatory proteins. Cyclins bind to Cdks, activating the Cdks to phosphorylate other molecules.
So, the correct option is ‘binding to cyclin, plus, phosphorylation by Cdk activating protein kinases’.
Which cellular organelles are involved in initration of intrinsic pathway of apoptosis?
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ER
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lysosme
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mitochondria
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All of the above
The death of cells which occurs as a normal and controlled part of an organism's growth or development is called apoptosis. In this endoplasmic reticulum, lysosome, mitochondria, Golgi complex are involved.
So, the correct option is ‘ER, lysosome, mitochondria’.
Which represents the correct sequence of stages in the cell cycle?
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$G _1$ ,$G _2$, S,M
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$G _1$, $G _2$,M,S
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$G _1$ ,M, $G _2$,S
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$G _1$ , S, $G _2$,M
The cell progresses through defined phases of the cell cycle during its division.
Of the total duration of cell cycle, the interphase lasts more than.
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$95$%
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$5$%
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$90$%
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$92$%
The cell is not allowed to past the cell cycle restriction point, DNA damage is detected. Which of the following proteins are involved in detection of DNA damage and inhibition of cycle at the restriction point?
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Replication protein A (RPA)
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ATM (ataxia telangiectasia mutated ) protein
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Cyclin D
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PSS
A. Replication protein (RPA) - is the major protein that binds to single-stranded DNA (ssDNA) in eukaryotic cells. ... During DNA replication, RPA prevents single-stranded DNA (ssDNA) from winding back on itself or from forming secondary structures.
B. ATM (ataxia telangiectasia mutated ) protein
It activates checkpoint signalling upon genotoxic stresses such as ionizing radiation (IR), ultraviolet light (UV), or DNA replication stalling, thereby acting as a DNA damage sensor.
C.Cyclin D - a member of the cyclin protein family that is involved in regulating cell cycle progression.
D.PSS - an autoimmune disease of the connective tissue. It is characterized by thickening of the skin caused by the accumulation of collagen, and by injuries to small arteries.
So, the correct option is ‘Replication protein A (RPA)’.
In order to enter cell cycle a cell must be stimulated from outside. What type of molecule provides this stimulation?
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cyclin
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colk
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cytokines and growth factor
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tyrosine kinases
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Cyclin-dependent kinases, through phosphorylation, signal the cell that it is ready to pass into the next stage of the cell cycle. As their name suggests, Cyclin-Dependent Protein Kinases are dependent on cyclins, another class of regulatory proteins. Cyclins bind to Cdks, activating the Cdks to phosphorylate other molecules.
Select the correct option:
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Interphase and M phase
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Prophase, metaphase, anaphase and telophase
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$G _1$, S and $G _2$ phases
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Karyokinesis and cytokinesis
The cell cycle starts from interphase . Interphase is the phase in the cell cycle that prepare a cell and its nucleus for division. It has three stages- $G _1,S $ and $G _2$.M- phase is the final phase of cell cycle..It represent the phase of actual division. It consists of karyokinesis (division of nucleus ) and cytokinesis (division of cell protoplast).