Cell Division - Mitosis
Cell cycle phases and mitosis processes
Questions
DNA replication takes place in
- G1 phase
- S phase
- G2 phase
- M phase
Which of the following statements is true about G1 phase?
- DNA content doubles in G1 phase.
- There is no change in DNA content of cell in G1 phase.
- Chromatin treads are formed in G1 phase.
- No cell organelles are formed in G1 phase.
Cell cycle continues in
- meiosis
- mitosis
- Both 1 and 2
- Neither 1 nor 2
In which phase of cell cycle are the proteins required for the formation of spindle fibres formed?
- Metaphase
- Prophase
- G2 phase
- S phase
If one cell cycle takes 100 minutes for completion, then time spent in M-phase is
- 30 minutes
- 40 minutes
- 10 minutes
- 20 minutes
Who used the term mitosis for the first time?
- Strasburger
- Fleming
- Nageli
- Virchow
In animal cells, astral rays in prophase emerge out from
- telomeres
- centromeres
- centrioles
- centrosomes
In which phase of mitosis do nucleoli and nuclear membrane disappear?
- Metaphase
- Anaphase
- Telophase
- Prophase
Why can chromosomes be best identified and counted at metaphase?
- Because chromosomes are arranged at the equator
- Because each chromosome becomes more compact and short
- Spindle fibres are attached at each centromere
- Chromosomes become thick and long
In which phase do chromosomes start becoming visible under light microscope?
- Prophase
- Anaphase
- Metaphase
- S-phase
Which is the most suitable phase for counting and identifying chromosomes?
- Telophase
- Metaphase
- Anaphase
- Prophase
The duration of cell cycle in humans is
- 20 minutes
- 22-25 hours
- 20 hours
- 26 hours
In which phase of mitosis does centromere divide into two?
- Prophase
- Metaphase
- Anaphase
- Telophase
What happens during telophase?
- Nuclear membrane reappears.
- Chromosomes form chromatin network.
- Spindle fibres disappear.
- All of the above
What is the chemical composition of spindle fibres?
- Cellulose
- Proteins
- Pectin
- Lipids