Copying DNA, dividing the cell
Copy the DNA, share the apparatus.
Where does the copy go?
A cell makes a copy of its DNA. Now it has two copies. Someone says, "Just keep one copy and push the other out of the cell."
What do you think happens to the copy pushed out?
What this lesson covers
The idea
A basic event in reproduction is making a DNA copy along with an additional cellular apparatus; the DNA copies then separate, each with its own apparatus, so one cell divides into two.
Where does the copy go?
A cell makes a copy of its DNA. Now it has two copies. Someone says, "Just keep one copy and push the other out of the cell."
What do you think happens to the copy pushed out?
- It cannot keep life going by itself
- It becomes a new cell at once
- It joins the first copy again
Copy and divide
Press Next step to watch one cell become two.
Copy, then share
Each new cell needs both: the DNA and a working cellular apparatus. That is why the cell makes the apparatus along with the DNA copy, and then the two sets go to two cells.
A basic event in reproduction is making a DNA copy along with an additional cellular apparatus. The DNA copies then separate, each with its own apparatus, so one cell divides into two.
Notes
Reproduction makes a DNA copy and an additional cellular apparatus. The copies separate, each with its own apparatus, and one cell divides into two.
Check yourself
Why does it not work to keep one DNA copy and push the other one out of the cell?
What is created along with the DNA copy?
What is the result when the DNA copies separate, each with its own cellular apparatus?
- Pushing out takes too much energy. The book's reason is that the pushed-out copy would not have any organised cellular structure for maintaining life processes.
- The copy pushed out has no organised cellular structure to maintain life processes — correct. Yes!
- Cells cannot make a copy of DNA. Cells use chemical reactions to build copies of their DNA. The problem is what happens to a copy with no cellular structure.
- Nothing else, only DNA is copied. The book says DNA copying is accompanied by the creation of an additional cellular apparatus.
- A second body for the organism. What is created is an additional cellular apparatus, so that each DNA copy has its own.
- An additional cellular apparatus — correct. Yes!
- One cell divides to give two cells — correct. Yes!
- Two DNA copies stay together in one cell. The copies separate, each with its own apparatus, and the cell divides to give two cells.
- A cell with no DNA is formed. Each of the two cells gets a DNA copy and its own cellular apparatus.