3.2.2 All Cells Arise from other cells

Question 1

What is the cell cycle?

Answer 1

The cycle in which a cell divides

Question 2

What are the main stage of the cell cycle?

Answer 2

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokenisis

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Question 3

What is interphase?

Answer 3

1. DNA unravelles and is replicated to double its geneitc content
2. Its organelles also begin to replicate and ATP levels increase
   (The cell carries out its usual function while interphase is happening)

Question 4

What is prophase?

Answer 4

1. Chromosomes condense by getting shorter and fatter
2. Tiny bundles of protien centrioles move to the poles of the cells
3. The nuclear envelope begins to break down

Question 5

What is metaphase?

Answer 5

1. Chromosomes line up at the equator of the cell
2. The spindle fibres from the centrioles attach to the chromosomes centromere

Question 6

What is anaphase?

Answer 6

1. The centromere divide seperating each pair of sister chromatids.
2. The spindle contract pulling chromatids to opposite poles
3. This makes the centromere look v-shaped

Question 7

What is telophase?

Answer 7

1. The chromatids reach the poles of the cell and begin to unfold
2. A nuclear envelope forms around each group of chromosomes

Question 8

What is cytokenisis?

Answer 8

The division of the cytoplasm to for two identical daughter cells

Question 9

Is mitosis controlled or uncontrolled. What can happen if it become uncontrolled.

Answer 9

Mitosis a type of controlled cell division
Tumors may occur due to uncontrolled cell division. Which could lead to cancer which is a tumor that invades the surrounding cell.

Question 10

Difference between Maliganant and Benign tumors

Answer 10

Maligant tumors are : Faster growing, Tumor metastisises (moves)
Benign tumors are : Slower growing, Tumor stay in one place.

Question 11

How do some cancer treatments work?

Answer 11

They focus on destroying parts of the cell cycle.
However, the treatments can’t distinguish between cancer cell dividing and normal cells divide.

Question 12

What happens if cell growth and protein production is stopped?

Answer 12

If no DNA was produced then the whole process is stopped as the next step of interphase cannot occur.

Question 13

What happens if DNA isn’t replicated?

Answer 13

At points in the cycle, the DNA is checked for damage and if it detects damage, then the cell kills itself preventing tumour growth.

Question 14

What binary fission?

Answer 14

The process during which prokaryotes replicate

Question 15

What is the process of Binary Fission?

Answer 15

1. Circular DNA (once) and plasmids (many times) replicate
2. The cell gets bigger and the circular DNA and Plasmids move to opposite poles
3. Cytoplasm begins to divide
4. The cell divides into two daughter cells

Question 16

What is viral replication?

Answer 16

Viruses aren’t alive therefore don’t undergo cell division.
Instead they inject their DNA/RNA into a host cell and replicate using their ‘machinery’ (organelles)

Question 17

What is the process of Viral Replication?

Answer 17

1. Virus attaches to the host cell with its attachment proteins
2. Genetic material is released into the host cell
3. Genetic material and proteins are replicated by the host’s ’machinery’
4. Viral components assembles
5. Replicated viruses related from host cell