Class XI Biology - MCQs

Which phase of the cell cycle is the longest?

• M phase

• G1 phase

• S phase

• G2 phase

The interphase consists of:

• G1 phase

• S phase

• G2 phase

• All of the above

DNA replication occurs during:

• G1 phase

• G2 phase

• S phase

• M phase

Mitosis results in:

• Four haploid cells

• Two haploid cells

• Two diploid cells

• Four diploid cells

Which checkpoint ensures that DNA has replicated correctly before mitosis begins?

• G1 checkpoint

• S checkpoint

• G2 checkpoint

• M checkpoint

Cytokinesis refers to:

• Division of cytoplasm

• Division of nucleus

• Division of DNA

• Division of mitochondria

Chromosomes become visible during:

• Interphase

• Prophase

• Telophase

• Metaphase

Which of the following is a phase of mitosis?

• G1

• G2

• Prophase

• S

Spindle fibers attach to chromosomes at:

• Centrosome

• Centromere

• Chromatid

• Nucleosome

Crossing over occurs in:

• Zygotene

• Pachytene

• Diplotene

• Leptotene