What I sometimes show students is a many-paged book. A thousand pages or so. Tell them to think that each page holds a thousand letters. Which makes a million letters in that book. Then say that you need approx 3000 books to equal the same amount of information which is contained by all chromosomes.
Of which there are 22 pairs plus X and Y
of which all are present in each cell in our body (except the ones you know, explain how & why later).
human body contains 3 zillion cells
And if you take all DNA contained in a human and lay it out in a straight line, you could go to the moon and back (or sumthing, dunno the exact comparison)

When a cell divides all 3 bill letters are copied for the new cell.

And then i usually would use some examples of when one of those 3 billion letters is wrong, you could get diseases like cystic fibrosis.

Alledged harmful radiation by cell-phones

99% of human and chimp DNA are homologues (more or less)
Only 30000 genes, many less then thought, examples of other organisms (flowers) with many more genes)

and other trivia i can't remember just now.

Good stuff!!

I will definitely use the book analogy (if I may?) it just so happens the core text is just over 1000 pages!

Some of the other stuff is outside the LO's but thanks for the help.

What I sometimes show students is a many-paged book. A thousand pages or so. Tell them to think that each page holds a thousand letters. Which makes a million letters in that book. Then say that you need approx 3000 books to equal the same amount of information which is contained by all chromosomes.
Of which there are 22 pairs plus X and Y
of which all are present in each cell in our body (except the ones you know, explain how & why later).
human body contains 3 zillion cells
And if you take all DNA contained in a human and lay it out in a straight line, you could go to the moon and back (or sumthing, dunno the exact comparison)

When a cell divides all 3 bill letters are copied for the new cell.

And then i usually would use some examples of when one of those 3 billion letters is wrong, you could get diseases like cystic fibrosis.

Alledged harmful radiation by cell-phones

99% of human and chimp DNA are homologues (more or less)
Only 30000 genes, many less then thought, examples of other organisms (flowers) with many more genes)

and other trivia i can't remember just now.

Talk about da different genes amongst humanz geographically!! How one can trace where their ancestorz came from, the life they led and da food they ate n stuff like dat. I read "The Seven Daughters of Eve" and it was incredibly interestingz!!