Question

1. what maintains cells efficiency in moving materials : select 2

a) cell is divided into smaller cells through mitosis b) temperature & ph of the cell
c) additional cell membranes d) stops growth and enters g₀ phase

1. what is the primary role of cell division?

a) to remove old cells that no longer function b) to add new cells needed for repair & replace
c) to help the stem cells to be specialized d) to make new copies from replication

1. match the correct phases of cell division

m - phase, prophase,s,g₁,anaphase,interphase,g₀,cytokenesis,g₂,telophase

1. _____ dna is replicated, also called synthesis.
2. _____ two new nuclei form, mitosis ends.
3. _____ chromosome pairs separate and move apart to opposite ends
4. _____ chromosome pairs meet in the middle.
5. _____ initial cell growth and in preparation for dna replication.
6. _____ nuclear membrane disappears, chromosome pairs become visible
7. _____ secondary growth in preparation for mitosis.
8. _____ cell division - the cell divides into two new daughter cells.
9. _____ 90% of the time the cell is in this phase,making copies and preparing for cell division.
10. _____ cell is resting, exits the cell cycle temporarily. the cell is alive and functioning but not actively involved in dividing.

Explanation:

1. Smaller cells have a higher surface - area - to - volume ratio which aids in material movement. Additional cell membranes can also increase the surface area for transport. Temperature and pH affect enzyme activity rather than directly maintaining cell material - movement efficiency, and entering the G₀ phase stops cell division and growth which is not related to material - movement efficiency.
2. Cell division primarily adds new cells for repair and replacement of damaged or old cells. Removing old cells is not the main role of cell division, helping stem cells specialize is a different cellular process, and making new copies from replication is part of the process but not the primary role of cell division as a whole.

20.

• S phase is when DNA replication (synthesis) occurs.
• Telophase is when two new nuclei form and mitosis ends.
• Anaphase is when chromosome pairs separate and move to opposite ends.
• Metaphase (not listed but the stage where chromosome pairs meet in the middle).
• G₁ is the initial cell growth phase and preparation for DNA replication.
• Prophase is when the nuclear membrane disappears and chromosome pairs become visible.
• G₂ is the secondary growth phase in preparation for mitosis.
• Cytokinesis is when the cell divides into two new daughter cells.
• Interphase is when the cell spends about 90% of its time, making copies and preparing for cell division.
• G₀ is when the cell is resting and exits the cell cycle temporarily while still being alive and functional but not actively dividing.

Answer:

1. a) Cell is divided into smaller cells through mitosis, c) additional cell membranes
2. b) To add new cells needed for repair & replace

20)

1. S
2. Telophase
3. Anaphase
4. (Metaphase - not in list but correct for this description)
5. G₁
6. Prophase
7. G₂
8. Cytokinesis
9. Interphase
10. G₀