binary fission and viral replication

Question 1

1. Describe how prokaryotes divide.

Answer 1

Binary fission occurs; Replication of the circular DNA; Division of cytoplasm to produce 2 daughter cells; Each with single copy of circular DNA; and a variable number of plasmids

Question 2

2. Describe how new viruses infect cells and are replicated

Answer 2

The virus’s attachment protein binds to receptors on the cell surface membrane. The viral nucleic acid enters the cell’s cytoplasm The viral DNA is replicated the cell uses viral DNA to make viral proteins viral DNA and protein are used to assemble new viruses The virus buds off wrapped in cell membrane which becomes its lipid envelope.

Question 3

3. Describe how viruses with RNA as their genetic material are produced?

Answer 3

The virus’s attachment protein binds to receptors on the cell surface membrane. The virus enters the cell by endocytosis. DNA copy made of viral RNA using reverse transcriptase; The DNA is inserted into host DNA the cell uses viral DNA to make viral proteins/particles; and makes new viral DNA The host cell makes new viruses; The virus buds off wrapped in cell membrane which becomes its lipid envelope.

Question 4

4. Why can cancer cells grow rapidly?

Answer 4

Mutations to DNA affect genes controlling cell division, accelerating the division of cells. Damaged cells usually get destroyed, but cancerous cells divide rapidly and form a tumour.

Question 5

5. What can uncontrolled cell division lead to?

Answer 5

The formation of tumours and cancers.

Question 6

6. How are cancer treatments targeted

Answer 6

Cancerous cells divide faster, cancer treatments target rapidly dividing cells and control the rate of cell division, therefore slowing the rate of growth of the tumour.