Cell cycle and cell division Flashcards
The two major characteristics of living cells are
Growth and reproduction
The three important events of a cell cycle are
Cell division, DNA replication and cell growth
The sequence of events by which a cell duplicates a genome, synthesises the other constituents of cell and eventually divides into two daughter cells is termed as
Cell cycle
A cell cycle of a typical eukaryotic cell which is illustrated by human cells in culture is completed in
24 hours
A yeast cell can complete one cell cycle is about
90 minutes
A cell cycle is divided into two basic phases, namely
Interphase and M phase(Mitosis phase)
The phase of cell cycle when actual cell division occurs is?
M phase (Mitosis phase)
The phase between two successive M phases is represented by
Interphase
The % duration of interphase during the cell cycle is
more than 95%
The % duration of M phase during the cell cycle is
Less than 5%
M phase starts with the process of
nuclear division
M phase ends with the process of
cytokinesis
The process of separation of daughter chromosomes is called
Karyokinesis
The process of division of cytoplasm is termed as
Cytokinesis
Interphase is also known as
resting phase
During interphase, cell prepares itself for division by undergoing both processes, namely ____ and ____
cell growth and DNA replicaton
The phase during which cell prepares for division is
interphase
Interphase is divided into 3 phases, namely
G1 phase, S phase and G2 phase
The phase which acts as an interval between mitosis and initiation of DNA replication is
G1 phase
The phase in which cell is metabolically active and continuously grows but does not replicate its DNA is
G1 phase
The phase of cell cycle during which DNA replication takes place
Synthesis phase
During S phase, the amount of DNA per cell
doubles
If the chromosome number is 2n, then by the end of S phase, it will be
2n
If the initial amount of DNA is 2C, then by the end of S phase, it will be
4C
In animal cells, during S phase, DNA replication begins in ___
nucleus
Duplication of centriole during S phase occurs in ___
Cytoplasm
Proteins for preparation of M phase are synthesised during ____
G2 phase
The cells of adult animals which do not undergo division are
heart cells
The cells which do not divide further exit G1 phase to enter into an inactive stage are called
Quiescent stage (G0)
The phase of cell cycle in which cells remain metabolically active but donot poliferate unless called upon is
Quiescent stage (G0)
The metabolic stage of cells during G0 phase is
Active
In animals, mitotic cell division is only seen in
diploid somatic cells
In which organisms, haploid cells divide by mitosis?
male honey bees
Reorganisation of virtually all components of the cell occurs during which phase?
M phase
The phase of cell cycle which is called as an equational division is
M phase
The four stages of karyokinesis are namely
Prophase, metaphase, anaphase and telophase
The first stage of karyokinesis occuring after G2 phase is
Prophase
The stage of mitosis marked by the initiation of condensation of chromosomal materials is
Prophase
During prophase, the structure which begins to move towards opposite poles of the cell is
Centrosome
Centrosome duplicates during ____ of interphase
S phase
During prophase, chromosomal material condenses to form compact mitotic ____
chromosomes
Chromosomes are composed of two chromatids attached together at
Centromere
Asters radiating out of centrosome are structurally
microtubules
Each centrosome radiates out microtubules called
asters
Mitotic apparatus is formed by spindle fibres and
2 asters
The component which along with asters form mitotic apparatus is
spindle fibres
The complete disintegration of nuclear envelope marks the start of which phase of mitosis?
metaphase
_____ of chromosomes is completed by the beginning of metaphase
Condensation
Metaphase is the stage to study ____ completely
Morphology of chromosomes