3.4 - Research in DNA Replication

Question 1

What are DNA strandds tightly wound up around?

Answer 1

Proteins, called histones

Question 2

What is the name of the protein that has DNA strands wound up around?

Answer 2

Histones

Question 3

What charge do histones have? Why/how does this help wound DNA around it?

Answer 3

Histones have a positive charg, which helps the DNA wrap around it because DNA has a slightly negative charge

Question 4

To replicate and and read DNA, what is required to happen?

Answer 4

It needs to be unwound first before those can occur

Question 5

What happens when a DNA strand is copied and the primers at the end are removed?

Answer 5

When there is a primer at the end that is removed, there is no DNA that replaces it.
Therefore, a little piece of genetic information is lost each time DNA is replicated

Question 6

What are telomeres?

Answer 6

• They are long repeating nucleotide sequences, placed at the end of new DNA strands
• They don’t have any genes or important information

Question 7

What are the purpose of telomeres?

Answer 7

It’s purpose is to be joined at the ends of replicated DNA strands, so that each time it gets copied, the piece that isn’t replaces is the telomere and not anything important.
From note : to be slowly lost each time the cell replicates

Question 8

What is the theory behind the natural loss/ decrease in telomeres?

Answer 8

It’s beleived to be a main factor as to why we age and die

Question 9

What is the protein that cancer cells have, that normal cells do not?
What is its purpose?

from DNA unit

Answer 9

They have a protein called telomerase.
Purpose : It lengthens telomeres. This prevents cancer cells from dying when they are supposed too.