Science week quiz Grade 9

What are the main stages of the cell cycle?

• Interphase (G1, S, G2) and Mitotic phase (M)

• Photosynthesis phases

• Protein synthesis steps

• Cellular respiration stages

During which phase does DNA replication occur?

• S phase

• M phase

• G1 phase

• G2 phase

What is the purpose of the G1 phase in the cell cycle?

• The purpose of the G1 phase is to prepare the cell for DNA synthesis and ensure it has the necessary resources for division.

• To repair damaged DNA from previous cell cycles.

• To facilitate protein synthesis for cell growth.

• To initiate mitosis and divide the cell immediately.

What happens during the S phase of the cell cycle?

• Protein synthesis is initiated, leading to cell growth.

• DNA replication occurs, resulting in the duplication of chromosomes.

• The cell prepares for mitosis by condensing chromatin.

• Cell division occurs, separating the chromosomes.

What is the role of the G2 phase before mitosis?

• The G2 phase is responsible for cell division.

• The G2 phase is when DNA is replicated.

• The G2 phase ensures the cell is fully prepared for mitosis by completing growth and organelle duplication.

• The G2 phase occurs after mitosis is complete.

What are the key events that occur during prophase?

• Spindle fibers disassemble and centrosomes move closer together

• Chromatin condenses, nuclear envelope breaks down, spindle forms, centrosomes move apart.

• Chromatin unravels and becomes less dense

• Nuclear envelope forms around the chromosomes

During which stage do the chromosomes align at the cell's equator?

• Metaphase

• Interphase

• Telophase

• Anaphase

What is the significance of anaphase in the cell cycle?

• Anaphase is when DNA is replicated before cell division.

• Anaphase occurs during the G1 phase of the cell cycle.

• Anaphase ensures proper segregation of chromosomes, crucial for genetic stability in daughter cells.

• Anaphase is responsible for the synthesis of proteins in the cell.

What occurs during telophase?

• Chromosomes decondense, nuclear envelopes reform, and spindle apparatus disassembles.

• Chromosomes replicate and align at the equator.

• Spindle apparatus forms and pulls chromosomes apart.

• Nuclear envelopes break down and chromosomes become visible.

the spindle apparatus of plants differs from that of animals in not having

• microtubules
• spindle fibers
• chromosomes
• centrioles